Browse Items (1651 total)

Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Family: Genus: Species:

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)

Mica-based schist containing significant quartz

This foliated sample is dominated by micas and quartz. It is a sample from the Hubbard Hill member.

Metamorphised sandstone with a gray, glassy appearance. From the Paughquag quartzite, a late Cambrian formation. The basal Cambrian quartzite rests on pre-Cambrian gneisses.

The thin section shows quartz and plag with some biotite and grain…

This specimen is typical of the 5-10 foot thick coarse grained layers of glassy quartzites that comprise this formation. In most instances the quartzites are about 90% quartz. Feldspar and garnet are encountered locally. This is presumed to be the…

Image is of the North Side of the Tanzawa Mountains (Wikipedia)

high-grade metamorphism

orthoclase is concentrated in watery clear megacrysts with crushed borders

This specimen displays an unusual and distinctive lithology that occurs primarily in lower, marble-rich units (for example, the Cedar River Formation).
Thin section shows quartz, K-feldspar and clinopyroxene.

contact with wall rock is sharp and with very thin, chilled margin

porphyritic, pink, coarse grained

Sample is not representative of whole body -- there are coarser and finer samples

Some feldspar shows slight alteration

slight iron staining, somewhat less leucocratic than other local features

medium-coarse grained

possibly quartz monzonite porphyry