Browse Items (1651 total)

Samples KBR-1, KBR-2, and KBR-2A are from a vertical mass of gabbro showing progressive differentiation inward. This sample is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both ranging…

Samples KBR-1, KBR-2, and KBR-2A are from a vertical mass of gabbro showing progressive differentiation inward. This sample is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both ranging…

Samples KBR-1, KBR-2, KBR-2A are from a vertical mass of gabbro showing progressive differentiation inward.This sample is the second sample for KBR-2. This sample is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are…

KBR-3 through KBR-6 are a second gabbro mass, distinguished from the first by a repetition of the differentiation cycle. The gabbro is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both…

KBR-3 through KBR-6 are a second gabbro mass, distinguished from the first by a repetition of the differentiation cycle. The gabbro is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals,…

KBR-3 through KBR-6 are a second gabbro mass, distinguished from the first by a repetition of the differentiation cycle. The gabbro is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both…

KBR-3 through KBR-6 are a second gabbro mass, distinguished from the first by a repetition of the differentiation cycle. Between the location this sample was collected and the location KBR-7 was collected there is a thin gabbro pegmatite that was…

Hand Sample: Aphanitic medium gray vesicular basalt with scattered olivine crystals. Olivine crystals are scattered throughout the sample and are either growing in clusters or as single crystals. Olivine crystals range in size from 0.05cm to 0.5cm in…

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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.

Sample from the beta member of the Toroweap formation. Sample is light tan-orangish with weathered surfaces.

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

Dark, finer-grained

Trachytes are an igneous volcanic rock with an aphanitic or porphyritic texture. Alkali feldspar, low amounts of plagioclase and quartz or a feldspathoid are common in trachytes.

Light gray

Hand Sample: Aphanitic dark gray trachyte. Sample contains zones with abundant tiny vesicles (less than 0.1cm in diameter), however the majority of the sample does not contain any vesicles or phenocrysts.

fine grained trap with abundant fragments of brecciated syenite

No associated sulfides