Browse Items (1651 total)

OCR PDF of supplemental information for the Grand Canyon collection.

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

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

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.

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.

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

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.

Green clay lithology of the Bright Angel Shale.

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.

Limestone containing fossils of the alga, Girvanella.

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

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.

Oblitic and Crinoidal Lithology.

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

Fine-grained limestone with occasional fossil remains.

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

Collected from the Redwall Formation, this is a highly silicious sample defined in the suite's documentation as chert, but the sample lacks the nano-crystalline appearance of a traditional chert. It appears to be more of a slightly metamorphosed…

Though listed as a limestone, this sample is best described as a conglomerate with calcite present in the matrix. This sample was collected from a bed of conglomerate lithology just below contact with Supai formation.

Both thin section images…

A classic red-bed sample typical of the sandstones from the Supai Formation.

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

Classic red-bed sample from the Supai Formation with silt-sized grains of mostly quartz. Some grains are semi-rounded.

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

A ferruginous sample.

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

A buff-colored siltstone/sandstone. The grains are angular and are quartz-dominated.

Thin section images were taken at a 400x magnification.

A sample from the gamma member of the Toroweap Formation. It is an orangish-brown sample.
Both thin section images were taken at a 400x magnification.