Browse Items (15 total)

  • Collection: (FR) Sedimentary and Igneous Franciscan Assemblage Suite -- California

DSC_1864.jpg
Clay sized feldspars and quartz present, but majority of crystal grains too small to identify in thin section. Surface contains some calcite that formed after lithification. Fresh surfaces do not effervesce with acid meaning reaction is caused by…

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Equal mix of angular and rounded sand-sized grains of quartz, with clay sized feldspars. Surface contains significant coverage of calcite that formed after lithification. Fresh surfaces do not effervesce with acid meaning that reaction is based on…

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Sand sized quartz grains and smaller feldspars make up the matrix. Grey-brown sand weathers to a rusty golden color.

(Thin Section FOV: 1.28mm)

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More orange in color that FR-3 (Red Chert). Radiolaria fossils are visible in thin section amongst red-orange martix.

(Thin Section FOV: 1.28)

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Coarse sand grains made of quartz, surrounded by smaller feldspar grains. Greenish blue surface color, minimal surface weathering.

(Thin section FOV: 1.28)

FR-9 PPL 100x.JPG
Fresh surfaces contain grey-white, anhedral calcite and dolomite crystals. Weathered surfaces are dark brown, with a fine powder observable after handling in hand sample. Bubbles from acid reaction turn dark brown on weathered surfaces. These…

FR-8 PPL 100x.JPG
Groundmass dominated by grey calcite and dolomite. Calcite and dolomite crystals are subhedral in thin section and hand sample.. (FOV: 1.28)

FR-7 XPL 100x.JPG
Angular sand size grains, dominated by quartz, have a brown color with a greenish tint. Calcite found on weathered bedding planes after lithification. Slight folding of the bedding planes in one direction. (FOV: 1.28)

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Holocrystalline, medium grained, anhedral, ophitic, dibastic crystals. Low silica percentage (46.3%) for a Diabase, bordering on ultramafic compostion. Calcite is present on weathered surfaces, but not on fresh surfaces. (FOV: 3.2mm)

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Angular, silty size gains, composed of equal parts quatz, feldspars and rock fragments. Prominent orange and brown surface oxydation on all samples. Some samples contain evidence of bedding planes. Calicte is found along bedding planes, as well as…

FR-4 XPL 100x.JPG
Fresh surfaces are dark blue in color, while weathered surfaces range in shades of green. Asbestos veins intersect throughout the rock, making up ~5% of the crystal mass. (FOV: 1.28)

FR-3 PPL 200x.JPG
Red jasper matrix with interescting veins of while quartz. Prominent physcial weathering, brittle areas fall apart to the touch. Several prominent fractures run through the rock, contributing to the weakened structure. Most fresh surfaces are reddish…

FR-2.jpg
Grain size is fine sand to silty sand, mostly angular with some rounded crystals. Various shades of surficial weathering with distinct pockets of orange-brown oxydation. Fresh surfaces brown-green in color. Collected from same quarry as sample FR-1.…

FR-1.jpg
Grain sizes sand to silty sand, rounded and angular with very minor examples of weathering and thin quartz vein present. Collected from the same quarry as FR-2. (FOV: 1.28mm)

FR.pdf
OCR PDF of supplemental information of the "Sedimentary and Igneous Franciscan Assemblage - California" collection.