Browse Items (1651 total)

Hand Sample: Holocrystalline, phaneritic, medium-grained granitoid with an abundance of alkali feldspar. Other minerals include quartz and biotite. Some chemical weathering has produced a white coating.

Hand Sample: Holocrystalline, phaneritic, porphyritic, diorite with quratz crystals up to 3mm in diameter set in a field of smaller light gray, and dark gray crystals. Some small oxidized pyrite crystals. Very weathered on two sides to orange yellow…

Hand Sample: Holocystalline, phaneritic, medim-grained granitoid with subhedral grains of smoky quartz, plagioclase feldspar, potassium feldspar, and biotite. Weathering to red-yellow on some surfaces.

Dark colored phaneritic peridotite containes micas, garnets, olivine pyroxene and plagioclase all visible from hand sample. Sample is speckled with light colored material and larger crystals of pyroxcene, olivine and michas visible in hand sample,…

Dark grey to black peridotite, phaneritic texture, containing numerous phenocrysts with a soft grey to white color. Small crystals of olivine visible in hand sample, characterized by a darker color than the surrounding rock and a more glassy luster,…

Dark grey to black, aphanitic texture, fine grained matrix, smooth texture, euhedral light-colored garnets, pyroxene and garnet cystals in thin section show a yellow border in plain polarized light, additional long spindly pyroxene crystals visible…

Porphyritic texture with large (>0.5 cm) euhedral garnets in a fine grained, green matrix shows serpentinization, one side containing mass of light colored transloucent pyroxcene; contains pyroxcene, plagioclase, olivine.

Thin Section.
Large…

Collected from blocks moved during road construction. Have been moved perhaps 200 yards. More quartzite and igneous and crystaline metamorphic rocks than at Sternenberg sampling site. Thin Section Coarse to fine (7-.1 mm) poorly sorted grains of…

Sandstone with ripple marks and cross bedding and strong flute casts along surface indicating mid-high energy. Poorly sorted coarse sandstone with ripple marks, cross bedding and strong flute casts, as well as small pebbles that vary from angular to…

Shale, foliated, and bearing organic matter, from the interbeds between sandstone layers. Fine grained laminated sands between shales were uncollectible, but present. Friable and fragile.

Thin Section:
Very fine to fine grain, poorly sorted…

Very fine grained sandstone and silty shale noted between shale and dark, fine grained sandstone (sample 4 &5).

Thin Section:
Very fine sized sub rounded grains of pyroxene, quartz, and feldspar in a calcic matrix.

Poorly sorted, coarse grained conglomerate; bearing chert, quartzite and granitoid fragments in calcite cement, with an odd mica flake indicating very short transport. The facies that this rock is representative of is uncommon. Conglomerate beds at…

Coarse grained mainly quartz sandstone with minor lithic and mud incorporated. Cross bedding present. Note the larger grain size of the sample, as well as the grains composed of conglomerate material indicating reworking of older sediments. Present…

Gray, medium to coarse grained quartz-rich lithic sandstone with rip up clasts and mud rich areas present. Thin Section Fine, (.7-.1 mm) sub angular crystal fragments floating in mud matrix, with feldspar, quartz, and pyroxene present.

Organic rich to moderate black to light grey shale. Some parts of FM-4 are silty shale. Minor rust stains are present on lighter samples. Representative of upper portion of a turbidite sequence.

Thin Section
Very fine (

Fine grained relatively soft calcareous sandstone. Thin Section Fine angular grains with fairly close packing characterize this thin section, with unusually sharp angles. Sample is still clay dominated.

Conglomerate, dominated by carbonate pebbles). Only a medium grained (1-10cm) facies collection of out of what was perhaps a 50ft exposure of coarse conglomerates. Light pink quartzite pebbles are interpreted to have been deposited during the…

Fresh water marl with plant remains. Specimens selected to include leaf and or stem remains. Hand sample specimen is small and crumbly. Fossil bearing biofloatstone composed of soft silt, mud and limestone matrix, with carbon imprint and original…

Rock Sample:
The color is mainly blue and black. The sample is aphanitic and the cross section of the sample reveals very fined grained phenocrysts (~1mm in diameter). The colors of the phenocrysts range from white, blue, black, or green.
It has…

Rock Sample:
The sample appears to be a conglomerate of crystals.The color is tan to dark green. The rock has low specific gravity . There are green, white, and brownish-orange clasts. There are some minor fractures on the outside of the sample. …