Metamorphic Rocks (Foliated textures)

Question 1

Fine-grained, aluminum-rich,
pelitic metamorphic rocks that possess flat, planar cleavage that develops during metamorphism under non-uniform stress at relatively low temperatures (-150- 200 °C) and low pressures.

Answer 1

Slate

Question 2

Rock cleavage characterized by larger crystals and more wavy surfaces compared to slaty cleavage.

Answer 2

Phyllitic Cleavage

Question 3

Metamorphic rock characterized by its phyllitic cleavage and glossy sheen, and commonly develop by the recrystallization of slate, possessing the same protolith as slates, at temperatures -250-300 °C and pressure conditions exceeding slates’.
-covered in phyllite

Answer 3

Phyllite

Question 4

A very common foliation defined by the sub-parallel arrangement of macroscopic platy minerals in closely spaced metamorphic layers.

Answer 4

Schistosity

Question 5

Metamorphic rock characterized with schistosity, enriched in aluminosilicate minerals, derived from various protoliths, and produced by dynamothermal metamorphism at convergent plate boundaries with temperatures ~300- 400 °C

Answer 5

Schist

Question 6

A foliation characterized by the arrangement of minerals into distinct color bands which are commonly alternating light-colored quartz and dark- colored biotites and amphiboles.

Answer 6

Gneissosity

Question 7

Metamorphic rock with a gneissose structure that develop from lower grade metamorphic rocks from a wide variety of protoliths, and form from dynamothermal settings at temperatures exceeding - 600 deg C
-Characterized by its compositional banding.

Answer 7

Gneiss

Question 8

Gneisses that develop from igneous protoliths.

Answer 8

Orthogneiss

Question 9

Gneisses that develop from sedimentary protoliths.

Answer 9

Paragneiss

Question 10

**“Mixed” rocks that possess textural and structural characteristics of both igneous and metamorphic rocks, **displaying an irregular, swirling mix of colors, and develop under high temperature (>800 °C) conditions in the lower crust.
-has myrmekitic texture

Answer 10

Migmatite

Question 11

Commonly banded metaquartzite that contains 20-30% iron.

Answer 11

Taconite

Question 12

Pervasively deformed metamorphic rocks that have their original composition and texture largely obliterated.

Answer 12

Tectonite

Question 13

A by-product glassy rock produced by the explosion during the Trinity Test.

Answer 13

Trinitite