Geology - Metamorphic Rocks Lab

Rocks to be identified on quiz.

What is it?

Garnet - Chlorite Schist

Foliated

Schistose

Med - high grade

no banding

macro micas

protolith → shale

What is it?

Gneiss

Foliated

compositional bands

high grade

felsic and mafic bands

protolith → shale

felsic → quartz and feldpsars

mafic → biotite/amphibole

What is it?

Marble

Non-foliated

protolith → calcite limestone

calcite cleavage

no particular grade

What is it?

Quartz - Muscovite Schist

Foliated

Schistose

Med - high grade

no banding

macro micas

protolith → shale

What is it?

Slate

Foliated

low grade

mostly clay minerals

slaty cleavage (like shale)

protolith → shale

What is it?

Quartzite

Non-Foliated

grains recrystallize and become very hard

sugary texture

not limiteds to grade

leisegang bands

protolith → quartz sandstone

What is it?

Serpentinite

Non - foliated

metamorphosed mantle (ultra mafic)

presence of a lot of fluids 

hydrothermally altered

rich in Mg and Fe

low grade

protolith → commonly peridotite ultra mafic

What is it?

Eclogite

Non-foliated

EXTREME depths and temperature

garnet, omphacite (bulk) and pyroxine

mafic protolith

denser than dunite

keeps slab pull in tectonics!!!

What is it?

Amphibolite

non-foliated

mostly amphiboles

high grade

mafic protolith

usually lack of other minerals

What is it?

Blueschist

Foliated

not actually schist

glaucophane dominant material

mafic protolith

located at accretionary prism

volcanic areas

What is it?

Phyllite

Foliated

protolith → shale

low side of intermediate grade

clay becomes micas

sometimes has graphite

usually chlorite

silky sheen