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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Volcanic Breccia
Description
An account of the resource
This is a volcanic breccia from the farm Murrelfontein adjacent to the contact with the gabbro unit. It includes partially melted glass and tridymite, a high temperature polymorph of quartz, and has a brecciated appearance. The breccia has a allotriomorphic- granular texture and is holocrystalline. Coarse, anhedral, chaotic-looking dark black crystals (3-12mm) are surrounded by slightly lighter colored, smaller anhedral crystals (2 mm -6 mm). There are trace olivine phenocrysts (2 mm).
Abstract
A summary of the resource.
<a href="http://link.springer.com/article/10.1007/BF00375423"><span>Differentiation of tholeiitic Karroo magma at Birds River, South Africa</span></a>
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-19
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
607_Dolerite_1
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
2560
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Bit Depth
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Dolerite
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Diabase or Microgabbro
Description
An account of the resource
This is dolerite from the "Dragon's Back" dyke, from the farm Romance. It is the youngest dolerite body in the area and contains biotite and hornblende. Emplacement of this dolerite took place at a much deeper crustal level than the gabbros. It has an aphanitic- porphyritic texture and is holocrystalline. The groundmass is light gray and subhedral. It contains slightly darker gray fine grained subhedral phenocrysts that comprise 30% of the dolerite. There is pinkish- brown blotchy weathering.
The thin sections are shown in plain polarized light and cross polarized light at a magnification of 400x and contains 60% plagioclase, 35% pyroxenes, and 5% opaques.
Abstract
A summary of the resource.
<span>Differentiation of tholeiitic Karroo magma at Birds River, South Africa</span>
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-18
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals. Inc.
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Metasomatised Pyroclastics
Description
An account of the resource
The metasomatised pyroclastics are from the farm Thysfontein. They are baked and well indurated. Induration is the hardening of rocks by heat or baking as well as the hardening of sediments by cementation or compaction. The pyroclastics are metesomatised, chemically altered by hydrothermal fluids. It has coarse to medium grained, holocrystalline,and hypidiomorphic-granular texture. There are black subhedral crystals (1 mm- 4 mm). The surface is weathered to be white and yellow. There are 1 mm- 2 mm pock marks of red staining on the fresh surface.
Abstract
A summary of the resource.
<a href="http://link.springer.com/article/10.1007/BF00375423"><span>Differentiation of tholeiitic Karroo magma at Birds River, South Africa</span></a>
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-17
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Adinole
Description
An account of the resource
Adinole was collected from the farm Murrelfontein and occurs above a conspicuous dolerite pegmatite. Adinole is a dense rock of mostly quartz and albite formed as the alteration product of contact metamorphism. It is potassium-rich and has hercynite, a mineral that can occur in high-grade metamorphosed iron rich argillaceous sediments. This adinole is a medium grained, holocrystalline, hypidiomorphic-granular texture.There are gray crystals ranging from < 1 mm- 3 mm. It has a dusty red and yellow weathered surface. It has a vein of a very dark aphanitic material.There is a radiating structure present in thin section.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-16
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
2560
Height
1920
Bit Depth
8
Channels
3
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Hornfels
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Contact Rock
Description
An account of the resource
This hornfels was collected from a section of contact metamorphism immediately above the dolerite of the formation from the farm Murrelfontein. It has "spots" of quartz, most likely inverted from tridymite spherulites, in a matrix of devitrified glass with mullite and cordierite. It has an aphanitic- porphyritic texture and is holocrystalline. The ground mass is light gray and anhedral, medium-grained dodecahedral brownish gray phenocrysts make up 25% of the hornfel. Some small spots of bright red iron staining (~1 mm) occur. The phenocrysts are opaque in thin section.
Thin sections are shown in plain polarized light and cross polarized light at a magnification of 40x. The rock is 70% quartz and 30% opaques. The groundmass is quartz.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-15
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
2560
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1920
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
2560
Height
1920
Bit Depth
8
Channels
3
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Porphyroblastic Metasediments
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Hybrid rock
Description
An account of the resource
The porphyroblastic metasediments/hybrid rocks were interpreted by Eales and his co-workers to be metamorphosed "Red Beds" Formation sediments but could be magmatic in origin. The samples illustrate the range in textures; see KBR 12 and KBR 13 to note this range. This sample is medium grained, holocrystalline, and has a hypidiomorphic-granular texture. It has dark gray crystals, ranging from < 1 mm- 3 mm. Dramatic labradorite-like striations cover about half of the rock. Groups of striations are roughly at right angles to one another. The rusty looking weathered surface is more vibrant on this rock (than the other samples).
The thin sections shown in plain polarized Light and cross polarized light at 40x magnification.
The rock is 60% plagioclase, 40% pyroxenes (mainly enstatite), and <1% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-14
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
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https://geosciencecollections.milne-library.org/files/original/5f5d36ab885ce119e95bba00cdcf0494.JPG
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
2560
Height
1920
Bit Depth
8
Channels
3
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Porphyroblastic Metasediments
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Hybrid rock
Description
An account of the resource
The porphyroblastic metasediments/hybrid rocks were interpreted by Eales and his co-workers to be metamorphosed "Red Beds" Formation sediments but could be magmatic in origin. The samples illustrate the range in textures; see KBR 12 and KBR 14 to note this range. This sample has an aphanitic- porphyritic texture and is holocrystalline. There is a light gray anhedral ground mass and medium-grained phenocrysts (1 mm- 3 mm).There are fine, snaky veins of reddish material on the fresh surface. Minor euhedral phenocrysts of plagioclase with reaction rims (4 mm).
The thin sections shown in plain polarized light and cross polarized light at 40x magnification.
The rock is 40% plagioclase, 20% pyroxenes (Enstatite), and 20% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-13
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
2560
Height
1920
Bit Depth
8
Channels
3
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Porphyroblastic Metasediments
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Hybrid rock
Description
An account of the resource
The porphyroblastic metasediments/hybrid rocks were interpreted by Eales and his co-workers to be metamorphosed "Red Beds" Formation sediments but could be magmatic in origin. The samples illustrate the range in textures; see KBR 13 and KBR 14 to note this range. This sample has an aphanitic porphyritic texture. There are unfoliated coarse-grained metasediments (2 mm- 4 mm) and subhedral muscovite phenocrysts (2 mm - 3 mm) as well as red anhedral phenocrysts. There is a rusty-looking weathered surface. In thin section, radiating pyroxenes are clearly visible.
Thin sections are shown in plain polarized light and cross polarized light at 40x magnification.
The rock is comprised of 70% plagioclase, 22% pyroxene (mainly augite), and 8% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-12
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Intersertal Ferrothoeleiite
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Ferrotholeiite
Description
An account of the resource
The intersertal ferrotholeiite samples are highly fractionated and were most likely emplaced before the gabbro of the formation. They have textures associated with rapidly frozen or highly viscous melts. KBR-7 through KBR-10 are also intersertal ferrotholeiites. Intersertal is a texture marked by the occurrence of interstitial glass between laths of feldspar, usually in basalts. It has an aphanitic porphyritic texture and is holocrystalline. It has a consistent dark gray color and contains fine veins of quartz <1mm wide. There are medium grained subhedral plagioclase phenocrysts (2 mm- 5 mm). There is a calcic residue on a heavily oxidized weathered surface. There is a subophitic micro-texture. Radiating pyroxenes are clearly visible in plain polarized light.
Thin sections are shown in plain polarized light and cross polarized light at 40x magnification.
The rock is comprised of 65% plagioclase, 30% pyroxenes (mainly enstatite), and 5% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-11
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
2
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Intersertal Ferrothoeleiite
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Ferrotholeiite
Description
An account of the resource
The intersertal ferrotholeiite samples are highly fractionated and were most likely emplaced before the gabbro of the formation. They have textures associated with rapidly frozen or highly viscous melts. KBR-7 through KBR-9 and KBR 11 are also intersertal ferrotholeiites. Intersertal is a texture marked by the occurrence of interstitial glass between laths of feldspar, usually in basalts. It has an aphanitic- porphyritic texture and is holocrystalline. It has a consistent dark gray color with fine veins of quartz < 1mm wide. There are medium grained subhedral plagioclase phenocrysts (2 mm - 5 mm). There is a calcic residue on a heavily oxidized weathered surface. There is also a subophitic micro-texture. Poikolitic pyroxenes are visible in plain polarized light.
Thin sections are shown in plain and cross polarized light at 40x magnification.
The rock is comprised of 70% plagioclase, 30% pyroxenes (mainly augite), and <2% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-10
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
2
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Intersertal Ferrothoeleiite
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Ferrotholeiite
Description
An account of the resource
The intersertal ferrotholeiite samples are highly fractionated and were most likely emplaced before the gabbro of the formation. They have textures associated with rapidly frozen or highly viscous melts. KBR-7, KBR 8, KBR 10, and KBR 11 are also intersertal ferrotholeiites Intersertal is a texture marked by the occurrence of interstitial glass between laths of feldspar, usually in basalts. It has an aphanitic- porphyritic texture and is holocrystalline. It has a consistent dark gray color and fine veins of quartz <1mm wide. There are medium grained subhedral plagioclase phenocrysts (2 mm- 5 mm). There is a calcic residue on a heavily oxidized weathered surface. There is also a subophitic micro-texture. Radiating pyroxenes are clearly visible in plain polarized light.
Thin sections are shown in plain and cross polarized light at 40x magnification.
The rock is made up of 55% plagioclase, 30% pyroxenes (mainly augite), and 15% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-9
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
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Bit Depth
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Intersertal Ferrothoeleiite
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Ferrotholeiite
Description
An account of the resource
The intersertal ferrotholeiite samples are highly fractionated and were most likely emplaced before the gabbro of the formation. They have textures associated with rapidly frozen or highly viscous melts. KBR-7 and KBR-9 through KBR-11 are also intersertal ferrotholeiites. Intersertal is a texture marked by the occurrence of interstitial glass between laths of feldspar, usually in basalts. It has an aphanitic- porphyritic texture and holocrystalline. It has a consistent dark gray color with fine veins of quartz <1 mm wide. There are medium grained subhedral plagioclase phenocrysts (2 mm - 5 mm). There is a calcic residue on a heavily oxidized weathered surface. Radiating pyroxene crystals are clearly visible in plain polarized light.
Thin sections are shown in plain and cross polarized light at 40x magnification.
The rock is comprised of 55% plagioclase, 15% pyroxene, 12% biotite, 10% opaques, and 8% olivine.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-8
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Intersertal Ferrothoeleiite
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Ferrotholeiite
Description
An account of the resource
The intersertal ferrotholeiite samples are highly fractionated and were most likely emplaced before the gabbro of the formation. They have textures associated with rapidly frozen or highly viscous melts. KBR-8 through KBR-11 are also intersertal ferrotholeiites. Intersertal is a texture marked by the occurrence of interstitial glass between laths of feldspar, usually in basalts. Between the location this sample was collected and KBR-6 was collected, there is a thin gabbro pegmatite which was not collected. It has an aphanitic porphyritic texture and is holocrystalline. It has a consistent dark gray color with fine veins of quartz < 1mm wide. There are medium grained subhedral plagioclase phenocrysts ( 2mm - 5 mm). There is a calcic residue on heavily oxidized weathered surface. A subophitic micro-texture is also present. Spherulitic pyroxenes are clearly visible in cross polarized light.
Thin sections are shown in plain and cross polarized light at 40x magnification.
The rock is composed of 40% plagioclase, 40% pyroxene (mainly augite), 10% biotite, 5% olivine, and 5% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc.
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-7
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals, Inc.
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
2
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Tholeiitic Gabbro
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Gabbro
Description
An account of the resource
KBR-3 through KBR-6 are a second gabbro mass, distinguished from the first by a repetition of the differentiation cycle. Between the location this sample was collected and the location KBR-7 was collected there is a thin gabbro pegmatite that was uncollected. This sample is medium grained and holocrystalline with a hypidiomorphic-granular texture.There are gray and black crystals, both about ranging from <1mm- 3mm. There is a reddish, rusty looking weathered surface. This rock has an average specific gravity.
Thin sections shown in plain and cross polarized light at 40x magnification.
The rock is made up of 65% plagioclase, 35% pyroxene, (mainly augite), and 3% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-6
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals Inc
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
2
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Tholeiitic Gabbro
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Gabbro
Description
An account of the resource
KBR-3 through KBR-6 are a second gabbro mass, distinguished from the first by a repetition of the differentiation cycle. The gabbro is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both ranging from <1mm- 3mm. There is a reddish, rusty looking weathered surface. This rock has an average specific gravity.
Thin sections shown in plain and cross polarized light at 40x magnification.The rock is made up of 80% plagioclase, 20% pyroxene (mainly augite), and ~2% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-5
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals Inc
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
2
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Tholeiitic Gabbro
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Gabbro
Description
An account of the resource
KBR-3 through KBR-6 are a second gabbro mass, distinguished from the first by a repetition of the differentiation cycle. The gabbro is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both ranging from <1mm- 3mm. There is a red rusty looking weathered surface. This rock has an average specific gravity.
Thin sections shown in plain and cross polarized light at 40x magnification.
The rock is made up of 65% plagioclase, 25% pyroxene (mainly augite), and 10% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-4
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals Inc
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Tholeiitic Gabbro
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Gabbro
Description
An account of the resource
KBR-3 through KBR-6 are a second gabbro mass, distinguished from the first by a repetition of the differentiation cycle. The gabbro is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both ranging from <1mm- 3mm.There is a red rusty looking weathered surface. The rock has an average specific gravity.
Thin sections are shown in plain and cross polarized light at 40x magnification.
The rock is made up of 65% plagioclase, 34% pyroxene (mainly augite), and <2% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-3
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals Inc
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Tholeiitic Gabbro
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Gabbro
Description
An account of the resource
Samples KBR-1, KBR-2, KBR-2A are from a vertical mass of gabbro showing progressive differentiation inward.This sample is the second sample for KBR-2. This sample is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both ranging from <1mm- 3mm. There is a red rusty looking weathered surface. This rock has an average specific gravity.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-2A
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals Inc
-
https://geosciencecollections.milne-library.org/files/original/54aaaaa5d93ffd48096e3d52c0e9f9de.JPG
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
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Height
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Bit Depth
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Channels
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Tholeiitic Gabbro
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Gabbro
Description
An account of the resource
Samples KBR-1, KBR-2, and KBR-2A are from a vertical mass of gabbro showing progressive differentiation inward. This sample is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both ranging from <1mm- 3mm. There is a red rusty looking weathered surface. This rock has an average specific gravity.
Thin sections are shown in plain and cross polarized light at 40x magnification.
The gabbro is composed of 70% plagioclase, 30% pyroxene (mainly augite), and <1% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-2
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals Inc
-
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The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
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Omeka Image File
The metadata element set that was included in the `files_images` table in previous versions of Omeka. These elements are common to all image files.
Width
2560
Height
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Bit Depth
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Channels
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Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
(KBR) Karroo Igneous Complex -- Birds River, South Africa
Description
An account of the resource
The Birds River Complex is a "Bell-Jar" intrusion first described by du Toit in 1905 and then by Ealey and Robey in 1976. One of the best exposed sections across the margin of the complex is on the farm Denwood, in the southwestern corner of the complex. The samples were collected from a mafic intrusion near Denwood farm. These samples from the Karroo Complex were collected from the previously studied section of the complex and neighboring areas.
Contributor
An entity responsible for making contributions to the resource
Dr. Brian Lock, Rhodes University
Western Minerals, Inc.
References
A related resource that is referenced, cited, or otherwise pointed to by the described resource.
<strong>Start Here:<br /></strong>Cox, K.G., 1972, The Karroo Volcanic Cycle: Journal of the Geological Society, v. 128, p. 311-336.<span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages">Â doi: 10.1144/gsjgs. 128.4.0311.<br /></span></span>
<ul><li>The petrogenesis of the Mesozoic igneous rocks of south-Eastern Africa is related to the tectonic event believed to be the initiation of the break up of Gondwanaland. The cycle began with the rise of potassium-rich picritic magma, the source material for rocks of the northern province, Rhodesia. On top of and peripheral to the main magma body, a zone of sodic magma was generated and formed some of the rocks of the north and most southern rocks.</li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><br /><strong>Additional resources:<br /></strong>White, R.S., 1992, Magmatism During and After Continental Break-Up, Geological Society, London, Special Publications, v. 68, p. 1-16. doi:Â <span>10.1144/GSL.SP.1992.068.01.0.<br /></span></span></span></span>
<ul><li>Magmatism that goes along with continental break-up is caused primarily by decompression melting of the underlying mantle as it rises up beneath the rift. The amount of melt produced is determined by the asthenospheric mantle temperature and on the rate of rifting. </li>
</ul><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span class="cit-sep cit-sep-after-article-pages"><span>Eales, H.V., and van Robey, J.A., 1976, Differentiation of Tholeiitic Karroo Magma at Birds River, South Africa, Contributions to Mineralogy and Petrology 10. v. 56, p. 101-117. doi:Â <span>10.1007/BF00375423<br /></span></span></span></span></span>
<ul><li>Strongly fractionated residue from the partial crystallization of tholeiitic gabbroic magma was emplaced at depth within sediment of the upper part of the Karroo succession. The residue was most likely tapped from a deeper intrusion during cauldron subsidence, but was engulfed by a later intrusion of olivine gabbro on a large scale.</li>
</ul>
Walker, F., and Poldervaart, A., 1949, Karroo Dolerites of the Union of South Africa, Geological Society of America Bulletin, v. 60, p. 591-706. doi: 10.1130/0016-7606(1949)60<span>[591:KDOTUO]2.0.CO;2</span><br /><ul><li>The Karroo dolerites are the result of the intrusive phase of the early Jurassic basalts that built up the Basutoland lava plateau. Most of the dolerites show little differentiation but olivine rich types and acidic veins have been recorded. The magma had an effect on the sedimentary rocks; many of the rocks described as granophyre were found to be transformed siltstone. The dolerites occur as sills and dikes but "bell-jar inclusions" occur (the Bird's River complex is a bell jar shaped inclusion). </li>
</ul>
Eales, H.V., and Booth P.W.K., 1974, The Birds River Gabbro Complex, Dordrecht District, Transactions of the Geological Society of South Africa, v. 77, p. 1-15.<br /><ul><li>On the gabbros of the Birds River Complex.</li>
</ul>
Rock
A physical material with a mineral composition.
Unit
Formation or other descriptive rock category
Lesotho Formation
Number of Thin Sections
Number of thin sections associated with this sample
1
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
A name given to the resource
Tholeiitic Gabbro
Alternative Title
An alternative name for the resource. The distinction between titles and alternative titles is application-specific.
Gabbro
Description
An account of the resource
Samples KBR-1, KBR-2, and KBR-2A are from a vertical mass of gabbro showing progressive differentiation inward. This sample is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both ranging from <1mm- 3mm. There is a red rusty looking weathered surface. This rock has an average specific gravity.
Thin section images are shown in plain and cross polarized light at40x magnification.
The gabbro is composed of 65% plagioclase, 30% pyroxene, 3% oIivine, and 2% opaques.
Date
A point or period of time associated with an event in the lifecycle of the resource
No date given.
Contributor
An entity responsible for making contributions to the resource
Western Minerals, Inc
Is Part Of
A related resource in which the described resource is physically or logically included.
http://www.geosciencecollections.milne-library.org/collections/show/17
Identifier
An unambiguous reference to the resource within a given context
KBR-1
Spatial Coverage
Spatial characteristics of the resource.
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
Temporal characteristics of the resource.
183-179 Ma (Jurassic)
Accrual Method
The method by which items are added to a collection.
Purchased from Western Minerals Inc