Metamorphic Rocks

In this image of a metamorphic rock viewed through a petrographic microscope, the preferred orientation of the mineral grains is ________, indicating that the direction of greatest compression was oriented ________.

• The grains are too inequant to have a preferred orientation.

• There is no preferred orientation.

• horizontal; vertically

• vertical; horizontally

Tags

NGSS.MS-ESS2-2

What is a metamorphic rock?

• Metamorphic rocks are any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed.

• Metamorphic rock is formed through the cooling and solidification of magma or lava.

• Metamorphic rocks arise from the transformation of existing rock types into an entirely different type of rock that form from the combination of heat, pressure, and time.

• Metamorphic rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by lithification.

This rock is rare. Only half of it has been metamorphosed into gneiss. The other half is the protolith. What is a protolith?

• A type of metamorphic rock that has distinct, repetitive layers. Sometimes these layers are very differently textured or colored.

• Rocks that arise from the transformation of existing rock types, in a process called metamorphism, which means "change in form".

• The original rock from which a given metamorphic rock is formed.

• Metamorphic rocks that appear massive or granular without the characteristic parallel mineral grains in foliated rocks.

Quartzite is the metamorphosed result of the rock that makes up Red Rock Canyon National Conservation Area in Las Vegas. What rock composes Red Rock Canyon and is the protolith of quartzite?

• Limestone

• Marble

• Sandstone

• Gneiss

Mount Charleston is composed primarily of the sedimentary rock limestone. Limestone is the protolith of what metamorphic rock?

• Quartzite

• Gneiss

• Sandstone

• Marble

Phase changes create polymorphs of the original mineral. What is the polymorph of andalusite at 0.2 GPa (pressure) and 450°C?

• andalusite

• kyanite

• sillimanite

• does not exist

Tags

NGSS.MS-PS1-1

The rocks on this map that underwent the deepest burial are now exposed at the surface in which state?

• Rhode Island

• Maine

• New York

• Massachusetts

Tags

NGSS.MS-ESS1-4

NGSS.MS-ESS2-2

Cite factors that can result in metamorphism.

• increased pressure

• lithification of sediment

• weathering and erosion

• increased temperature

Choose the statement that best describes this foliation.

• an alignment of mineral grains perpendicular to the direction of compression

• the texture typical of all metamorphic rocks

• an arrangement of mineral grains that aligns the minerals in various directions

• an alignment of mineral grains parallel to the direction of compression

The metamorphic rock shown below is best classified as

• slate

• schist

• gneiss

• phyllite