Browse Items (1651 total)

A silty-shale where the clasts are dominated by quartz. Sample collected from an area typified by interbedded limestones and shale.

Both thin section images were taken at a 400x magnification.

Limestone containing fossils of the alga, Girvanella.

Both thin section images were taken at a 400x magnification.

Red siltstone lithology of the Bright Angel Shale.

Both thin section images were taken at a 400x magnification.

Green clay lithology of the Bright Angel Shale.

Both thin section images were taken at a 400x magnification.

Mottled lithology of the Muav Limestone.

Both thin section images were taken at a 400x magnification.

Sandstone shows metamorphic overprinting with triple junctions between quartz grains common.

Both thin section images were taken at a 400x magnification.

This sample is mis-labeled as a pegmatite. It is really a porphyritic dike material that cuts through the Zoroaster Granite. The phenocrysts are hornblende.

Part of the The Granite Gorge Metamorphic Suite, this is usually considered a metavolcanic, and its mineralogy is dominated by quartz and mica.

Both thin section images were taken at a 400x magnification.

Both cross polarized and plain polarized images were taken at a 400x magnification.

Both thin section images were taken at a 400x magnification.

OCR PDF of supplemental information for the Grand Canyon collection.