EXAM 2 Igneous Rocks, EXAM 2 Sedimentary Rocks, EXAM 2 Metamorphic Rock

magma

BENEATH Earth's surface, often generated in upper asthenosphere and lithosphere in magma chambers

lava

ON Earth's surface, composed of silicate minerals

What is the difference between the formations of chalk versus chert?

They are made of different source materials.

A porphyritic texture where large crystals are embedded in a matrix of small crystal may form when ________.

a magma that has partially crystallized slowly moves to a different location where it then cools rapidly

rock

a solid aggregate of one or more minerals, or mineral material

confining pressure

applies forces equally in all directions

Most commonly, felsic igneous rocks ________________.

are lighter in color than mafic rocks

plutons

blob-shapes intrusions that solidify from magma chambers

burial metamorphism

bottom of thick sedimentary rock piles

mechanical weathering

breaking apart of rock

erosion

broken fragments are removed

Igneous rock is formed ________.

by crystallization of magma

Precipitation of gypsum due to evaporation of seawater produces which kind of sedimentary rock?

chemical

What type of sediments are found in lake bottoms?

clay/mud

how is sediment turned into solid rock?

compaction and cementation

sedimentary rock

compaction and cementation of sediments

alluvial fan

conglomerate and arkose

As compared to coarse-grained igneous rocks, fine-grained igneous rocks ______________.

cool and solidify more quickly

extrusive rock crystal size?

cool fast/small crystals

intrusive rock crystal size?

cool slowly/large crystals

igneous rocks

cooling of molten rock

shallow marine

coquina

dikes

cut across rock layers

chemical weathering

dissolving of the minerals

composition

felsic, intermediate, mafic, ultramafic

texture

fine(aphanitic), coarse(phaneritic)

When a metamorphic rock exhibits a layered or banded appearance, it is said to exhibit a(n) ________ texture.

foliated

schist, slate, gneiss

foliated metamorphic rocks

clastic rock

formed from fragments of other rocks, coarse/medium/fine grained

slow rate of cooling

forms large crystals

fast rate of cooling

forms small crystals

biochemical rock

fossils, fine and coarse grained

heat comes from?

from magmatic intrusions

schist turns into?

gneiss

playa lake

halite

The primary agent of contact metamorphism is ________.

heat

cause changes?

heat and pressure

contact/thermal metamorphism

heat, pre-existing rock comes into contact w molten lava or magma, recrystallize DOES NOT MELT

Lithification occurs ________.

in the shallow subsurface

ripple marks

indicate a shallow stream or ocean environment

mud cracks

indicate arid environment that was drying out

angularity

individual clasts become more rounded and smoother the further they are transported

phaneritic texture

individual mineral grains can be seen w the naked eye

Compaction and cementation of grains occur during ________.

lithification

sorting

long distance transport sifts grains, and carries smaller ones farther leaving coarser ones behind

sediment

loose materials, such as rock fragments, mineral grains, and the remains of once-living plants and animals, that have been moved by wind, water, ice, or gravity.

Slate is associated with ________ metamorphism.

low grade

"formed by fire" examples

magma and lave

Which of the following minerals is particularly prominent in schist?

mica

deep marine

micrite and fossiliferous limestone

rocks classified according to:

mineral composition, chemical composition, texture, how they were formed

cementation

minerals precipitate between the grains, forming mineral cement

porphyritic texture

mixture of coarse and fine crystals, two-stage cooling (slow then fast)

mafic

more dark minerals (black), Augite

felsic

more light minerals, Quarts or K-Feldspar

regional metamorphism

mountain building, greatest volume of metamorphic rock produced, heat and pressure used

lake

mudstone and shale

delta

mudstone and siltstones

marble and quartzite

non-foliated metamorphic rocks

Non-Foliated Metamorphic Rock

not banded, do not break into layers, massive crystalline, pressure

foliated metamorphic rock

parallel layers of bonds, directed pressure

sills

parallel to rock layers

Every metamorphic rock has a ________ from which it formed.

parent rock

protolith

parent rock, metamorphic rocks hold same chemical composition as parent, mineral makeup determines degree of change

slate turns into?

phyllite

organic rock

plant material, fine grained

An irregular-shaped and blob-like igneous rock body that cooled beneath the surface of Earth is a ________________.

pluton

Which igneous texture is characterized by two distinctively different crystal sizes?

porphyritic

The primary difference between breccia and conglomerate is that conglomerate ________.

possesses more rounded grains than breccia

chemical rock

precipitation/evaporation of water, crystalline

compaction

presses the grains together

Metamorphosed sandstone is known as ________.

quartzite

Coarse-grained granite is most similar in mineral composition to fine-grained ________.

rhyolite

Which of the following changes may occur during metamorphism?

rock becomes more compact, crystals may grow larger, certain minerals may recrystallize

"formed by fire"

rocks formed from molten rock material

plutonic or intrusive rocks

rocks formed inside Earth, phaneritic, several colors **rich in Magnesium and Iron

volcanic or extrusive rocks

rocks formed on the surface, aphanitic(crystals too small to see w naked eye), single color, glassy

intermediate

same amount of dark minerals as light (salt and pepper), Hornblende

phyllite turns into?

schist

A fine-grained clastic sedimentary rock that splits into thin sheets is ________.

shale

Siltstone or mudstone containing marine fossils likely formed in a ________ environment.

shallow-marine

shale turns into?

slate

During metamorphism, the material undergoing deformation remains a ________.

solid

weathering

solid rock is broken down

rock cycle

system that links subsurface processes driven by Earth's internal heat to surface processes driven by solar energy

Intrusive igneous rocks are often coarse-grained because ________.

the slow cooling at depth allows large crystals to grow

Grains become rounded primarily during ________.

transportation

The mineral olivine is characteristic of a ________ magma.

ultramafic

differential pressure

unequal in different directions

batholith

vast composite, intrusive, igneous rock formed by the intrusion of numerous plutons in same region

ultramafic

very dark in color, mostly olivine (green)

If magma or lava cools quickly, the resulting igneous rock will have ________.

very small crystals

If a geologist found preserved mud cracks, he or she could conclude that the environment in which they formed ________.

was once covered in wet mud

metamorphic rock

when a rock changes shape/form

does heat increase in temperature with depth?

yes - geothermal gradient

does pressure increase with depth?

yes - mountain formations