metamorphic rocks

Vesicles are the result of

gas expansion (bubbles), which often occurs during volcanic eruptions.

Metamorphic rocks with segregated light and dark minerals are called

gneiss

Porphyritic textured rocks

is really a subtype, but usage of the term often confuses the beginner. rocks are composed of at least two minerals having a conspicuous (large) difference in grain size.

What does the term protolith mean?

parent rock before metamorphism

What metamorphic environment is most likely to result in the rock gneiss?

regional metamorphism

granite chemical composition

felsic

Which of the following rocks represents the highest metamorphic grade

gneiss

which rock has mineral banding where the light and dark minerals are separated?

gniess

Place these rocks in order from highest silica content to lowest silica content.

granite diorite gabbro peridotite

Which of the following metamorphic rocks is not paired with its true parent rock?

hornfels - dolomite

Vesicular

if the rock contains numerous holes that were once occupied by a gas phase, then this term is added to the textural description of the rock.

Scoraceous

if vesicles are so abundant that they make up over 50% of the rock and the rock has a density greater than 1, then the rock is said to be scoraceous.

Pumiceous

if vesicles are so abundant that they make up over 50% of the rock and the rock has a density less than 1 (i.e. it would float in water), then the rock is pumiceous.

In contact metamorphism there is a

local heat source

The metamorphic rock that is white, but it can occur in a variety of colors. It will fizz with hydrochloric acid. What is it's rock name?

marble

Which of the following metamorphic rocks can not form from a shale?

marble

nonfoliated rocks

marble ambhibolite quartzite

Previously existing rocks transform into new rocks due to an increase in heat and pressure

metamorphic

During metamorphism a quartz arenite will change into what type of rock

quartzite

As magma moves up through the crust, pieces of already solidified rock fall into the magma chamber. What is the name for this process?

Magma assimilation

What process allows for a previously existing rock to change WITHOUT melting?

Solid state recrystallization

Phaneritic cooling

This texture forms by slow cooling of magma deep underground in the plutonic environment.

The intrusion of dikes and sills would likely cause what type of metamorphism?

Contact metamorphism

What are the three main categories for depositional environments?

Continental Marine Transitional

What is the name of our state rock?

Serpentinite

A geothermometer is?

a mineral assemblage that can reveal the minimum temperature attained during heating

Fibrous

a term used to describe grains that occur as long fibers

Acicular

a term used to describe grains that occur as long, slender crystals.

Prismatic

a term used to describe grains that show an abundance of prism faces.

Tabular

a term used to describe grains with rectangular tablet shapes.

Spherulitic

a texture commonly found in glassy rhyolites wherein spherical intergrowths of radiating quartz and feldspar replace glass as a result of devitrification.

Graphic

a texture consisting of intergrowths of quartz and alkali feldspar wherein the orientation of the quartz grains resembles cuneiform writing. This texture is most commonly observed in pegmatites.

Obicular

a texture usually restricted to coarser grained rocks that consists of concentrically banded spheres wherein the bands consist of alternating light colored and dark colored minerals.

What are the categories of sedimentary rocks? Select all that apply.

biochemical chemical organic detrital

what minerals are found in Phaneritic Rocks

biotite mica, potassium feldspar, quartz, hornblende

Which of the following metamorphic rocks forms in the forearc of a subduction zone

blueschist

In which of the following metamorphic environments would you expect to find bedding and other sedimentary structures to be preserved

burial metamorphism

Limestone and marble are made up of the mineral

calcite

Alluvial fan/deltas

conglomerate

Sediments are broken rock and mineral fragments only.

false

What is the chemical composition of andesite?

intermediate

Shallow marine

limestone

A rock that has undergone cataclastic metamorphism would most likely display which of the following

pulverized rock fragments

magma type Andesitic

solidified Andesite

magma type Basaltic

solidified Basalt

magma type Rhyolitic

solidified Rhyolite

A combination of shallow earthquakes, tension, and contact metamorphism characterizes

spreading centers

In regional metamorphism the source of increased temperature and pressure is

the increase in temperature with increasing depth of burial

The pressure and heat that drive metamorphism result from which three forces?

the internal heat of the Earth, the weight of overlying rocks, and horizontal pressures developed as rocks become deformed

Which of the following is not used to classify foliated rocks

the texture of the parent rock

Pyroclastic Texture

those blown out into the atmosphere during violent volcanic eruptiions. These rocks are collectively termed fragmental. t is comprised of numerous grains or fragments that have been welded together by the heat of volcanic eruption.

Porphyritic cooling

undergone two stages of cooling; one at depth where the larger phenocrysts formed and a second at or near the surface where the matrix grains crystallized.

Vesicular Texture

vesicles (holes, pores, or cavities) within the igneous rock.

Which category of sedimentary rocks is classified mainly be it's grain size?

Detrital

What type of metamorphism lead to the formation of our state rock?

Hydrothermal metamorphism

examples of limestone.

Oolitic Chalk Coquina

What is the one and only texture that an intrusive igneous rock can have? (according to my powerpoint)

Phaneritic

Pumice and scoria are common types of

Vesicular rocks

Incomplete melting of rocks within our crust due to differences in melting temperatures is termed....

partial melting

what metamorphic rock has a waxy appearance.

quartzite

During metamorphism, changes in the bulk composition of a rock occur primarily as a result of

reaction with hydrothermal fluids

What type of metamorphism is caused by high temperature and high pressure imposed over a large volume of crust

regional

glassy textured rocks

textured igneous rocks are non-crystalline meaning the rock contains no mineral grains.

Phaneritic textured rocks

textured rocks are comprised of large crystals that are clearly visible to the eye with or without a hand lens or binocular microscope. The entire rock is made up of large crystals

Metasomatism is

the change in the bulk composition of a rock during metamorphism

What is the relationship between metamorphic foliation and sedimentary bedding

there is no regular relationship between sedimentary bedding and metamorphic foliation

a very smooth, silica rich rock. It was often used to make arrowheads, and today jewelry. There are a lot of variations of this one rock. It is also a sedimentary rock! What is it's rock name?

chert

What TWO rocks have a gravel sized grains?

conglomerate & breccia

Which type of pressure will result in the alignment of metamorphic minerals?

directed pressure

glassy cooling

results from cooling that is so fast that minerals do not have a chance to crystallize. This may happen when magma or lava comes into quick contact with much cooler materials near the Earth's surface.

Beach, barrier island

sandstone

The atmosphere causes erosion and weathering of rocks/minerals which eventually solidify into a new rock.

sedimentary

Deep ocean

shale

Which of the following sets is arranged in order of increasing metamorphic grade?

shale - slate - phyllite

index minerals forms at the highest metamorphic grade?

sillmanite

Select all the foliated rocks.

slate phylitle schist gneiss

A rock rich in garnet and pyroxene that forms at extremely high pressures and moderate to high temperatures is called a(n)

eclogite

lava cools rapidly not allowing any mineral crystals to grow

extrusive igneous

There are two categories of metamorphic rocks. What are they?

foliated, nonfoliated

The parallel alignment of mica in a metamorphic rock is an example of

foliation

What is the most prominent textural feature of regional metamorphic rocks?

foliation

Which of the following rocks formed extrusively? Select all that apply.

Basalt Rhyolite

Within a 50 mile traverse you walk from a shale into a slate into a phyllite. You are walking in the direction of

increasing metamorphic grade

Magma cools slowly forming large minerals.

intrusive igneous

A Geologist suffers from a black eye after yelling "Gneiss!!!" to a classmate, who happened to be sunning on a large boulder. The geologist really meant to tell the classmate that the rock they were laying on

is a high-grade, silicate-rich, mineralogically banded metamorphic rock

retrograde metamorphism

is the process where rocks previously metamorphosed under high-grade conditions are later metamorphosed under low-grade conditions

You observe mud cracks in the rock record. What depositional environment would be the safest interpretation of this observation?

Dried lake bed (playa)

Depositional environments are where the sediment was deposited after it was lithified.

False

Marble is a metamorphic rock that forms from a ___________ parent

limestone

Which of the following rocks would react with hydrochloric acid because it's made of calcite?

limestone

Sediments become sedimentary rocks through the process of

lithification

chalk is actually an example of which sedimentary rock?

Limestone

Which of the following rocks can be considered gradational between an igneous rock and a metamorphic rock?

migmatite

Both ____ and ____ rocks can be porphyritic,

aphanitic and phaneritic

Hydrothermal metamorphism is very common in which of the following settings?

at mid-ocean ridges

What igneous process is most probably at a divergent boundary?

decompression melting

Metamorphism occurs

adjacent to igneous intrusions, along faults, in subduction zones

A magma

consists mostly of liquid rock matter, but may contain crystals of various minerals, and may contain a gas phase that may be dissolved in the liquid or may be present as a separate gas phase.

The main factor that determines the texture of an igneous rock is the

cooling rate

An igneous rock is any

crystalline or glassy rock that forms from cooling of a magma.