Just spent all evening in the lab sawing up my samples to get sent off and made into thin sections! This was my first time ever using the rock saw, and it’s both terrifying and super fun!
Tag: geology
Staurolite
Scoria
Scoria is an extrusive igneous rock formed during volcanic eruptions. It is highly vesicular, meaning that it has many cavities (vesicles) both inside and at its surface. It has a very low density, so for a rock, it’s pretty darn light! Image by author
Larvikite
Larvikite - igneous rock from Norway featuring ternary feldspar
Metamorphic Rocks
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Thin sections
Talc-actinolite schist in thin section Images by author
<3 Geology
Heart-shaped greenschist facies pillow basalt from Ely, Minnesota.
Banded Iron Formation, Soudan
Some absolutely gorgeous ~2.7 Ga Banded Iron Formation (BIF) from Soudan, Minnesota. The rotating silver and reddish layers are hematite and jasper respectively, and these BIFs differ from their Proterozoic counterparts in that they were chemically precipitated. The outcrop is intensely folded and shows numerous interference patterns, meaning that there are folds that have been… Continue reading Banded Iron Formation, Soudan
Pegmatite
Red Ace Pegmatite (WI); Lithium feldspar with pink tourmaline
Welded Tuff
Welded tuff is a type of pyroclastic rock. A pyroclastic deposit consists of fragmented material that is formed from explosive volcanic activity or from aerial expulsion from a volcanic event. These pyroclasts may be deposited in the form of pyroclastic flows [a dense, ground-hugging cloud of ashy material], forming ignimbrites (Greek for “fire cloud material”).… Continue reading Welded Tuff
Emily Zawacki, Ph.D. 