Metamorphic Rocks Review (2025)

Which rock forms by the recrystallization of unmelted rock material under conditions of high temperature and pressure?

• granite

• gneiss

• rock gypsum

• bituminous coal

Use the described student decision chart for identifying rock samples. The chart starts at “Rock Sample,” then branches to “Igneous Rock” (intrusive/extrusive) and “Sedimentary Rock” (clastic/bioclastic/chemical), or to “Metamorphic Rock” (foliated/nonfoliated). Which rock specimen should lead the student to choice 4, path (a), which corresponds to Metamorphic → Foliated?

• peridotite

• quartzite

• gneiss

• dolostone

Slate is formed by the

(a)  

• deposition of chlorite and mica

• foliation of schist

• metamorphism of shale
• folding and faulting of gneiss

A rock sample shows distorted banding in wavy layers. This rock would be classified as metamorphic because it shows

• distorted banding

• an organic composition

• a mixture of minerals

• crystals from precipitation

A classification scheme divides rocks into “Sedimentary” and “Nonsedimentary.” Sedimentary rocks can be formed by compaction and cementation (examples: rock gypsum, dolostone, breccia). Nonsedimentary rocks are divided into “Igneous” (example: granite) and “Metamorphic” (circle C).

If the rock in circle C formed from limestone, it would be called

• schist

• anthracite coal

• marble

• quartzite

Which sequence of change in rock type occurs as shale is subjected to increasing heat and pressure?

Place in order. BEGIN WITH SHALE

• phyllite

• slate

• gneiss

• schist

• shale

A diagram shows four rock samples labeled A, B, C, and D. Which sample best shows the physical properties normally associated with regional metamorphism?

During the intrusion of the Palisades Sill, contact metamorphism changed sandstone and shale into

• diorite

• marble

• limestone

• hornfels

A geologic cross section shows sedimentary rock layers, igneous intrusions, and zones of contact metamorphism. At the contact between rock E and rock F, which rock most likely formed in the zone of contact?

• obsidian

• slate

• metaconglomerate

• sandstone

Which physical characteristic best describes the rock phyllite?

​ (a)   texture with​ (b)  

• gas pockets
• angular fragments
• cemented shell fragments
• foliated
• microscopic mica particles
• glassy
• clastic
• bioclastic