Brahma Schist
Part of the The Granite Gorge Metamorphic Suite, this is usually considered a metavolcanic, and its mineralogy is dominated by quartz and mica.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-2
Bright Angel Shale
Green clay lithology of the Bright Angel Shale.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-6
Bright Angel Shale
Red siltstone lithology of the Bright Angel Shale.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-7
Bright Angel Shale
A silty-shale where the clasts are dominated by quartz. Sample collected from an area typified by interbedded limestones and shale.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-9
Chert
Collected from the Redwall Formation, this is a highly silicious sample defined in the suite's documentation as chert, but the sample lacks the nano-crystalline appearance of a traditional chert. It appears to be more of a slightly metamorphosed quartzose sandstone.
Modal Abundances:
Quartz (95%)
Matrix (5%)
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-12
Coconino Sandstone
A buff-colored siltstone/sandstone. The grains are angular and are quartz-dominated.
Thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-17
Grand Canyon Western Minerals Supplementary Information
OCR PDF of supplemental information for the Grand Canyon collection.
Western Minerals Inc.
Western Minerals Inc.
no date
GCsuite
Hermit Shale
A ferruginous sample.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-16
Kaibab Limestone
A light tan limestone with weathered surfaces
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-20
Muav Limestone
Mottled lithology of the Muav Limestone.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-5
Muav Limestone
Limestone containing fossils of the alga, Girvanella.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-8
Pegmatite
This sample is mis-labeled as a pegmatite. It is really a porphyritic dike material that cuts through the Zoroaster Granite. The phenocrysts are hornblende.
no date
Western Minerals Inc.
GC-3
Redwall Limestone (Conglomerate)
Though listed as a limestone, this sample is best described as a conglomerate with calcite present in the matrix. This sample was collected from a bed of conglomerate lithology just below contact with Supai formation.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-13
Redwall Limestone (green conglomerate lithology)
Fine-grained limestone with occasional fossil remains.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-11
Redwall Limestone (Oblitic and Crinoidal Lithology)
Oblitic and Crinoidal Lithology.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-10
Supai Sandstone
A classic red-bed sample typical of the sandstones from the Supai Formation.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-14
Supai Shale
Classic red-bed sample from the Supai Formation with silt-sized grains of mostly quartz. Some grains are semi-rounded.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-15
Tapeats Sandstone
Sandstone shows metamorphic overprinting with triple junctions between quartz grains common.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-4
Toroweap Limestone
A sample from the gamma member of the Toroweap Formation. It is an orangish-brown sample.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-18
Toroweap Limestone
Sample from the beta member of the Toroweap formation. Sample is light tan-orangish with weathered surfaces.
Both thin section images were taken at a 400x magnification.
no date
Western Minerals Inc.
GC-19