Browse Items (1651 total)

Hand Sample: Aphanitic dark gray vesicular basalt. Basalt has ropey pahoehoe texture on top surface and contains numerous elongated vesicles.

Hand Sample: Aphanitic vesicular dark gray-black basalt with larger light crystals throughout the sample. The vesicles throughout the sample are elongate in shape, and range in size from 0.5 cm to 2.5 cm. Sample surface displays rough AA texture.

Hand Sample: Aphanitic light gray hawaiite with inclusions containing numerous vesicles. Inclusions are darker in color with abundant vesicles less than 0.01cm in diameter. The surface of the sample is heavily weathered, resulting in sample's tan…

Hand Sample: Aphanitic, light gray alkalic olivine basalt. Sample contains abundant feldspar phenocrysts ranging in diameter from 0.1cm to 0.9cm in length. Phenocrysts are generally blocky in shape. Occasional vesicles throughout sample ranging in…

Hand Sample: Aphanitic, light-gray alkalic olivine basalt. Sample contains abundant phenocrysts of feldspar, olivine, and augite. Phenocrysts range in diameter from 0.1cm to 0.5cm. Many of the phenocrysts in sample have an iridescent luster. Sample…

Hand Sample: Aphanitic dark gray vesicular oceanite with phaneritic olivine crystals. Olivine crystals are scattered throughout the sample and are either growing in clusters or as a single crystal. Olivine crystals range in diameter from 0.1cm to…

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…

Hand Sample: Dark gray, vesicular, glassy sample. Sample surface has a ropey texture with vesicles ranging from 0.01cm to 2.5cm in diameter. Sample has an iridescent luster on unweathered surfaces.

Hand Sample: Glassy, dark gray, vesicular pumice. The sample contains many small pieces of the pumice, ranging from 0.03cm to 1.5cm in diameter. Chunks of glassy pumice and volcanic ash compose sample.

Hand Sample: On cut face, aphanitic, gray basalt with light colored phaneritic crystals (~0.1 cm in size). Subparallel fractures noted across sample. Exterior of sample has been heavily weathered, resulting in the red and orange discoloration.

Hand Sample: Imperfect volcanic bomb. Aphanitic with reddish brown color. Observed mudcrack texture of surface likely formed due to weathering. Sample contains abundant vesicles (< 0.05cm in size).

Hand Sample: Apahanitic vesicular dark gray-black basalt. Larger (

Hand Sample: Aphanitic vesicular dark gray-black basalt. Sample contains numerous vesicles ranging in size from 0.01cm to 1.5 cm.

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…

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…

Sand sized quartz grains and smaller feldspars make up the matrix. Grey-brown sand weathers to a rusty golden color.

(Thin Section FOV: 1.28mm)

More orange in color that FR-3 (Red Chert). Radiolaria fossils are visible in thin section amongst red-orange martix.

(Thin Section FOV: 1.28)

Coarse sand grains made of quartz, surrounded by smaller feldspar grains. Greenish blue surface color, minimal surface weathering.

(Thin section FOV: 1.28)

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…

Groundmass dominated by grey calcite and dolomite. Calcite and dolomite crystals are subhedral in thin section and hand sample.. (FOV: 1.28)