Black Silty Shale
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 secondary calcite growth.
(Thin Section FOV: 0.64mm)
Not given
Western Minerals, Inc.
FR-14
Graywacke
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 secondary calcite formation.
(Thin Section FOV: 1.28mm)
Not given
Western Minerals, Inc.
FR-13
Graywacke
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)
Not given
Western Minerals, Inc.
FR-12
Radiolarian Chert and Shale
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)
Not given
Western Minerals, Inc.
FR-11
Arkosic Graywacke
Coarse sand grains made of quartz, surrounded by smaller feldspar grains. Greenish blue surface color, minimal surface weathering.
(Thin section FOV: 1.28)
Not given
Western Minerals, Inc.
FR-10
Calera type Limestone
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 weathered bubbles leave behind a brown residue. Bubbles on fresh faces remain white and leave no residue. (FOV: 1.28)
Not given
Western Minerals, Inc.
FR-9
Calera-type Limestone with Chert
Groundmass dominated by grey calcite and dolomite. Calcite and dolomite crystals are subhedral in thin section and hand sample.. (FOV: 1.28)
Not given
Western Minerals, Inc.
FR-8
Graywacke
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)
Not given
Western Minerals, Inc.
FR-7
Diabase
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)
Not given
Western Minerals, Inc.
FR-6
Graywacke Siltstone
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 on some surfaces perpendicular to bedding. Some samples include very fine calcite veins (<0.5mm) intersecting through the bedding planes. (FOV: 1.28)
Not given
Western Minerals, Inc.
FR-5
Serpentine
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)
Not given
Western Minerals, Inc.
FR-4
Red Chert
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 brown while weathered surfaces are brown to orange. (FOV: 0.64mm)
Not given
Western Minerals, Inc.
FR-3
Arkosic Graywacke
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. (Thin Section FOV: 1.28mm)
Not given
Western Minerals, Inc.
FR-2
Arkosic Graywacke
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)
Not given
Western Minerals, Inc.
FR-1
Sedimentary and Igneous Franciscan Assemblage - California: Western Mineral's Inc. Supplementary Information
OCR PDF of supplemental information of the "Sedimentary and Igneous Franciscan Assemblage - California" collection.
PDF
FR-suite