TEST 2 GEOL

What kind of melting is expected at subduction zones?

Flux-induced melting

What rocks have banded foliations?

Gneiss and Migmatite

Give an example of a place currently undergoing continental rifting:

East African Rift

With increasing P, inside the earth:

High density minerals are formed

Dikes and sills are

High-angle, low-angle igneous intrusions

What does sorting of a clastic sedimentary rock indicate?

Number of sources involved

What is the primary factor that keeps the mantle rocks from melting at very high temperatures of 3000 C?

Overburden pressure

Metamorphic grade implies

P, T Conditions of a rock environment

Metamorphism implies

P, T, Stress, Fluid conditions of a rock environment

what rock displays glassy black textures

obsidian

What is a chemical sedimentary rock?

Oolitic Limestone

Burial metamorphism is common in

Sedimentary basins

The Grand Canyon has what type of rocks exposed?

Sedimentary, Igneous and metamorphic rocks

What would you call a very fine clastic grained sedimentary rock with clay minerals?

Shale

T/F: A conglomerate can contain volcanic glass

T

T/F: Sedimentary formations are arranged in layers

T

T/F: Sedimentary formulations are mappable

T

T/F: Sedimentary formulations may contain sedimentary structures

T

Does tabular or spherical chambers cool faster

Tabular

What does red shale tell us about its depositional environment?

The enviro of deposition was exposed to atmosphere

The original, unmetamorphosed rock from which a given metamorphic rock is formed (parent rock)

protolith

another name for fragmental texture is

pyroclastic texture

What minerals are part of Bowen's Reaction Series?

Ca- and Na- rich plagioclase

What is the dominant mineral composition of marble?

Calcite

What is the dominant mineral in limestone?

Calcite

Give an example of LIP in continental US:

Columbia River Flood Basalts

Vesicles in vesicular textures are remnants of

Volatile passages in an igneous rock

The rock type produced by contact metamorphism is called

hornfels

Match: Volcano tops

High T/Low P metamorphism

fragmental texture is formed from

Volcanic ash and rock debris

What is a temperature adequate for Metamorphism?

200-700 F

Alternating red and black shales in a sedimentary sequence indicate that the deposition environment experienced:

A rise and fall of sea level

What is a biochemical sedimentary rock?

Chalk

What words may be used t describe portions of rock with porphyritic texture

Aphanitic, Phenocrysts, Groundmass

Cross beds indicate

Average flow direction

Where would you expect a chemical sedimentary rock like salt to be deposited?

Beaches

What would you call a rock that has pebble-size angular clasts?

Breccia

What sequence represents a correct sequence of deposition away from source?

Breccia-Conglomerate-Sandstone-Shale

Lithification involves:

Burial, Compaction & Cementation

in a flux-inducing melt, what can act as flux

CO2, H2O, SO2

Alluvial fan is a type of depositional environment where the following happens:

Changes in riverflow velocity, change in slope of the land, deposition of sediments eroded from mountain tops

A low-grade metamorphic rock containing chlorite-biotite-muscovite is subjected to higher P/T conditions> Which mineral will be replaced first during neocrystallization?

Chlorite

All phaneritic textures are

Coarse-grained, derived from magma, and cooled slowly

What is process that can turn a sedimentary rock into a metamorphic rock?

Contact, Subduction, Burial - metamorphism

List 3 tectonic and/or mantle processes that trigger decompression melting

Continental rifting, sea floor spreading, mantle plume

What rock is made entirely of marine organisms?

Coquina

Ripple marks on sandstone indicate

Current flow conditions

What kind of melting is expected at mid-ocean ridges?

Decompression melting

What kind of melting is expected in a continental rift tectonic setting?

Decompression melting

Graphite after new P/T conditions that causes it to become unstable and convert into a new phase:

Diamond

Match: Mylonites

Dynamic metamorphism

Quartzite and marble lack foliation why?

Equant mineral grains

What process cools rocks inside the Earth?

Exhumation

T/F: A granite can contain olivine

F

T/F: A metamorphic rock can contain shell fragments

F

Pyroclastic flow occurs in:

Felsic melt flows and Extrusive settings

All aphanitic textures are

Fine-grained, derived from lava, and cool faster

Principle of uniformitarianism states that:

Geologic processes occurring now, happen throughout Earth's history

The characteristic mineral for subduction zone metamorphism which imparts blue hue to the subduction zone metamorphic rocks is:

Glaucophane

During metamorphic crystallization, there is a change in:

Grain size of the protolith minerals and the texture

A coarse grained magmatic igneous rock with 65% SiO2 and containing minerals like quartz, K-feldspar may be called:

Granite

Porphyritic rocks are named for the size of

Groundmass grains

Match: Deeper parts of subduction zones

High P/High T metamorphism

Chemical alteration of ocean floor basalts is an example of

Hydrothermal metamorphism

A dike intrudes into

Igne, Sedi, Meta rocks

A metamorphic rock-specimen contains the minerals muscovite and biotite but no chlorite, what can you infer about the P/T conditions where the rock was formed?

Intermediate P/T

Felsic magma:

Is more viscous than mafic magma

Flood basalts are characteristic of

LIPs

LIP is

Large Igneous Provinces

Hot rock melt outside the earth:

Lava

The dominant rock type in coral reefs is:

Limestone

What is the parent rock of marble?

Limestone

Hot rock melt inside the earth:

Magma

Match: Accretionary Prism

Low T/High P metamorphism

What kind of igneous rocks do you expect at mid-ocean ridges?

Mafic fine-grained

Composition of the earths mantle is

Mafic to Ultramafic

How would you get an igneous rock from an igneous rock?

Melting

What rock would react with acid?

Micrite, Limestone, Chalk

What is an example of a rock with banded foliations?

Migmatite

Which is a mixed rock (meta-igne)

Migmatite

During metamorphism in a compressive stress field, how does the mineral acquire preferred orientation?

Mineral long axes aligns normal/perpendicular to the direction of maximum compressive stress

Why does molten rock move upward through the Earth's mantle?

Molten rock is less dense than the surrounding solid rocks

Regional metamorphism is typical of

Mountain belts

A small stream in an arid region which is experiencing severe droughts for a few years continuously is expected to best preserve the following sedimentary structures:

Mudcracks

What minerals crystallize via the discontinuous reaction series

Olivine, Pyroxene, amphibole

What is the dominant mineral in sandstone?

Quartz

When sandstone is metamorphosed, it turns to:

Quartzite

What is a metamorphic rock that is coarse-grained?

Quartzite, Gneiss, Schist

What does black shale tell about its depositional environment

Reducing marine conditions

How would you get a metamorphic rock from an igneous rock?

Reheating

What is a rock with visible mineral grains?

Schist

What is a protolith of Gneiss?

Schists, Shale, Granite

What is the sequence of increasing grain size inside Earth: Schist, Slate, Phyllite, Gneiss?

Slate-phyllite-schist-gneiss

What is the sequence of increasing metamorphic grade inside Earth: Schist, Slate, Phyllite, Gneiss?

Slate-phyllite-schist-gneiss

What is a mineral found in impact craters only?

Stishovite

List 4 tectonic settings where igneous activity occurs

Subductions, Midocean ridges, continental rifts, hotspots

Where would you expect coal to be deposited?

Swamps

Sediments eroded from Putnam County by the Caney Fork River may be deposited in:

The gulf of mexico

Shock metamorphism is associated with:

Ultrahigh P/High T

Formation of migmatite is and indication of:

The rock has just entered the zone of melting in the Earth

what rock is not derived from an igneous rock ment?

Tuff

What is the correct order of melt compositions arranged in order of increasing viscosity

Ultramafic < Mafic < Intermediate < Felsic

What is the correct order of melt compositions arranged in order of increasing volcanic explosivity

Ultramafic < Mafic < Intermediate < Felsic

An igneous rock containing <45% SiO2 is called

Ultramafic Rock

A metamorphic rock contains the minerals coesite and diamond

Very high P conditions

How would you get a conglomerate from granite?

Weathering

Correct order of clastic rock formation: Erosion, Weathering, Deposition, Burial, Compaction, Cementation

Weathering-Erosion-Deposition-Burial-Compaction-Cementation

Does depth inside earth correlate to slower cooling (the deeper the slower)

Yes

Extrusive igneous rock textures can be:

aphanitic or glassy or fragmental in texture

Mafic igneous rocks tend to have _____ color shades

dark

an example of a hotspot induced volcanism

hawaii

intra-plate volcanism is seen at:

hotspots

a porphyritic texture is one in which

individual crystals are a mix of fine and coarse grained crystals

A phaneritic texture is one in which

individual crystals can be seen with the naked eye

An aphanitic texture is one in which

individual crystals cannot be seen with the naked eye

porphyritic textures indicate

initial slow cooling then fast cooling

Felsic igneous rocks tend to have _____ color shades

light

All intrusive igneous rocks have

phaneritic texture

coarse-grained crystals in porphyritic textures are called

phenocrysts

Vesicular texture is one in which

pores are abundant

In most types of metamorphism, bulk element composition of a parent rock is:

same as that of the parent rock

Bowen's Reaction Series

shows that minerals in a cooling magma crystallize in a predictable order.

Magma that is rich in volatiles is called

wet magma