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)
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)
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.
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)
Permanent Cement Co. quarry, near Cupertino. Take I 280 south from San Francisco to Foothill Expressway, then west to Stevens Creek Road, then right on Stevens
Creek Road to end.
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)
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)
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.
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)
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)
Roadcut on northwest side of Sausalito road east of US 101 and just north of Golden Gate Bridge. It is the first outcrop northeast of the Fort Barry Road
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)
Roadcut on east side of Highway 1 (Panoramic highway) 17 miles El of south side of Golden Gate Bridge go along US 101 then turn on state highway 1 to 17 miles,