Graywacke Siltstone

Title

Graywacke Siltstone

Identifier

FR-5

Description

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)

Date

Not given

Contributor

Western Minerals, Inc.

Spatial Coverage

Roadcut on south side of Petaluma Pt.
Reyes Station road 1/2 mi. upstream (east) from dam which is about 4 miles east of Point Reyes Station.

Temporal Coverage

Mesozoic

Accrual Method

Purchased from Western Minerals, Inc.

Number of Thin Sections

1