Geology

Due to old oceanic crust being recycled at subduction zones, all oceanic crust is less than _____

200 MA

Minerals are divided into mineral classes based on anionic groups. Carbonates, such as calcite (CaCo3), display _______ directions of cleavage where the cleavage planes are _____ to one another.

3; Inclined

The age of the earth is approximately ______

4.54GA

Phyllite (Metamorphic)

A fine-grained metamorphic rock with a well-developed laminar structure, and is intermediate between slate and schist rocks. Crinkled or wavy appearance.

Batholith

A mass of rock formed when a large body of magma cools inside the crust

Laccolith

A massive igneous body intruded between preexisting strata

cinder cone

A steep, cone-shaped hill or small mountain made of volcanic ash, cinders, and bombs piled up around a volcano's opening

Dikes

A structure built to prevent ocean waters from flooding adjacent land

glassy texture

A term used to describe the texture of certain igneous rocks, such as obsidian, that contain no crystals.

gneissic texture

A texture of metamorphic rocks in which dark and light silicate minerals are separated, giving the rock a banded appearance.

plate tectonics

A theory stating that the earth's surface is broken into plates that move.

slate

A type of Metamorphic rock that was once shale rock formed by heat and pressure.

slaty cleavage

A type of foliation that is characteristic of slates, in which there is a parallel arrangement of fine-grained metamorphic minerals.

dormant volcano

A volcano that has not erupted for a long time, but may erupt again one day.

extinct volcano

A volcano that has not erupted for thousands of years and probably will not erupt again.

alluvial fan

A wide, sloping deposit of sediment formed where a stream leaves a mountain range

flux melting

AKA Volatile-Driven Melting: Melting aided by the addition of water or other fluid -the addition of water to the already hot mantle rocks lowers their melting temperature resulting in partial melting of ultramafic mantle rocks to yield mafic magma.

hot spot

An area where magma from deep within the mantle melts through the crust above it

Foliation

An arrangement of minerals in flat or wavy parallel bands.

effusive eruption

An eruption that yields mostly lava, not ash.

Igneous rock has a different name depending on whether the rock is intrusive or extrusive, an intermediate composition igneous rock is called a ____ if extrusive and ____ if intrusive.

Andesite; Diorite

The distance a volcanic arc occurs from the trench is determined by the _____ of the down going lithospheric plate.

Angle

physical weathering

Any process that breaks rock down into smaller pieces without changing the chemistry of the rock; typically wind and water.

volcaniclastic debris

Ash, cinders, and blocks are all types of ____________.

Magmas can be modified in a number of ways, what is the process called where a magma body incorporates surronding country rock?

Assimilation

The lithosphere floats on a plastic layer called the ______ that flows very slowly at temperatures > 1,280 C

Asthenosphere

graded bedding

Bedding in which the particle sizes become progressively heavier and coarser toward the bottom layers

______ states that all matter and energy was packed into an infitesimally small point which exploded _____ years ago.

Big Bang Theory, 13.8 GA

The heated, mineral-laden water then circulates back out of the crust, which causes minerals to precipitate forming what feature?

Black Smokers

A turbidity current is the rapid downslope movement of a mizture of sediment and water which is denser than the surronding clear water producing a graded deposit with coarser grains at the _____ with finer grains at the _____

Bottom;Top

When a critical volume of magma have been evacuated from a magma chamber during an eruption, a collapse feature called a _____ is formed

Caldera

grain sizes

Clay, Silt, Sand, Gravel/Pebble, Cobble, Boulder

If a mineral breaks to form distinct planar surfaces that have specific orientation in relation to the crystal lattice, then the mineral exhibits _________

Cleavage

As a basaltic lava flow cools, the rock contracts due to heat loss, which may cause the rock to frature into a polygonal pattern called ____

Columnar Jointing

The viscosity of lava is primarily determined by it's ____, which in addition to _____ control the explosivity of an erruption.

Composition; volatiles

Conglomerate

Conglomerate is a coarse-grained clastic sedimentary rock that is composed of a substantial fraction of rounded to subangular gravel-size clasts, e.g., granules, pebbles, cobbles, and boulders, larger than 2 mm in diameter.

What type of metamorphism develops in response to heat without change in pressure or differential stress, typically due to an igneous intrustion, and would the metamorphic rock produced be foliated or non foliated?

Contact Metamorphism, Nonfoliated

_____ boundaries are marked by deep-ocean trenches and volcanic arcs where oceanic lithosphere subducts beneath an overriding plate

Convergent

Continental collision occurs at _____ when a buoyant piece of crust or an island arc moves into the subduction zone, causing the continetal crust to become _________ during collison.

Convergent Boundaries, Thicker

Lamination

Covering the surface of a material with a thin sheet of another material typically for protection, preservation or aesthetic reasons.

Sedimentary rock structures and textures

Cross Bedding and Ripple Marks, Dunes, Scour Marks, Tool casts, fossils, mud cracks, lamination, layering, stratification

What is the process called which modifies the composition of magma by mafic minerals crystallizing first and settling out of a magma body (therefor not reacting with it), enriching the liquid component of the magma in silica?

Crystal Fractionation

The _____ of a mineral referes to the shape of a single crystal with well-formed crystals faces.

Crystal Habit

Obsidian is often a black volcanic glass that has a similar chemical composition to the mineral quartz (SiO2). What feature does quartz have that obsidian does not that prevents it from being classified as a mineral?

Crystalline Lattice

What is the process called where hot mantle rock undergoes a decrease in pressure, commonly near mid-ocean ridges, causing a melt to form?

Decompression Melting

What process is responsible for gerenating a melt and the formation of new crust at Mid-ocean Ridges?

Decompression Melting

A _____ is a wedge of sediment that accumulates where moving water enters standing water and deposits sediment load, composed of gravely topset sandy foreset and silly bottomset beds.

Delta

cross bedding

Depositional feature of sedimentary rock that forms as inclined layers of sediment are carried forward across a horizontal surface

scour marks

Depressions or erosional features formed as a current flows across a bed of sand.

Which process caused the internal stratification of Earth into different layers, where heavier elements formed the core and mantle, while lighter elements formed the crust?

Differentiation

Eruptive Styles of Volcanoes

Effusive vs. Explosive Volatiles Viscosity Silica Content

If a mineral displays well-formed crystal faces then it is often described as a ____ crystal.

Euhedral

eustatic sea level

Eustatic (global) sea level refers to the sea level change of the volume of Earth's oceans. This is not a physical level but instead represents the sea level if all of the water in the oceans were contained in a single basin.

As the viscosity of a magma/ lava is increased, the resulting eruption is more likely to be ____

Explosive

At convergent plate boundaries, such as the Cascadia Subduction zone, an arc is formed where ____ eruptive styles are expected due to the ____ composition of magamas that are generated.

Explosive; silica-rich

Viscosity, or resistance to flow, depends on temperature, volatile content, and silica content. Based upon this information, which magma type would be the most viscous?

Felsic

What magmas are characterized by having the lowest concentration of iron (Fe) and magnesium (Mg) and the highest silica (SiO2)

Felsic

Large igneous provinces (LIPS') such as the columbia river plateau are broad pleateaus built by successive basaltic lava flows called ______

Flood Basalts

During subduction, volatiles such as H2O and CO2 are realses from the descending oceanic plate which lower the melting point of the hot rock above it, causing a melt to form in a process called _______

Flux melting

The rate of change in temperature with depth is called the:

Geothermal Gradient

Cementation/ Compaction

Gluing together of sediment and rock

What high grade metamorphic rock is typically composed of alternating felsic and mafic layers that range in thickness from millimeters to meters?

Gneiss

What perssure-temperature environment produces a blue amphibole called glaucophane?

High Pressure, Low Temperature

nonfoliated metamorphic rock

Hornfels, Quartzite, Marble

Ultramafic

Igneous rocks with low silica content and very high levels of magnesium and iron. Periodite, dunites, and doirite are examples.

Volcanic ash, or ash mixed with lapilli, typically deposited from a pyroclastic flow, form a/an ____ when transformed into a coherent rock after cooling and solidification.

Ignimbrite

The presence of certain minerals, known as ___ minerals, indicate the metamorphic grade which corresponds to the pressure and temperature of the parent rock was exposed to.

Index

Transgression vs. Regression

Ingression, Regression, and Transgression. A transgression is a landward shift of the coastline while regression is a seaward shift. The terms are applied generally to gradual changes in coast line position without regard to the mechanism causing the change.

Neocrystallization

Initial minerals become unstable and change to new minerals, original minerals are digested by chemical reaction

A magma with >55% and <65% SiO2 would be classified as a _____ type magma?

Intermediate

Plutons

Intrusive igneous rock bodies, including batholiths, stocks, sills, and dikes, formed through mountain-building processes and oceanic-oceanic collisions; can be exposed at Earth's surface due to uplift and erosion.

Igneous rock with a course grained interlocking crystalline texture is typically _____ and therefore has a _____ cooling rate.

Intrusive; slow

Which four elements make up approximately 91% of the Earths Mass?

Iron (FE), Oxygen (O), Silicon (SI), and Magnesium (MG)

Wet, ash-rich debris flows formed from the mixture of volcaniclastic debris with snow, ice, rain or water produce a volcanic debris flow with the consistency of wet cement is called

Lahar

The tranformation of a loose sediment into a solid rock is referred to as _________. Thus process involves two steps, compaction wher the weight of the overlying material squeezes out water and air trapped between clasts and ____ where sediments are stuck together by minerals that precipitate from groundwater to form a cohert sedimentary rock.

Lithification, Cementation

Plate Tectonics theory explains of all of the following except:

Location of polar ice caps

Shield volcanoes from broad, gentle domes due to the ____ viscosity of the lavas, causing them to spread out of large areas.

Low

Volatiles are released from subducting oceanic lithosphere, hydrous minerals, and water-rich sediments, which causes melting in the overiding plate due to volatiles ____ (Raising/Lowering) the melting point of minerals in the mantle wedge above.

Lowering

Lava vs. Magma

Magma is composed of molten rock and is stored in the Earth's crust. Lava is magma that reaches the surface of our planet through a volcano vent.

The heat source for hot spot volcanism is a ____ a column of very hot rock rising up through the mantle to the base of the lithosphere

Mantle Plume

Recrystalization of limestone forms a nonfoliated rock called _____ composed of interlocking calcite crystals

Marble

If the ripple crest is symmetrical, that indicates formation within a _____ enviornment while an inclined ripple crest indicates formation within a ______ environment

Marine; Fluvial

Continental Crust is _________ buoyant, and _________ dense than oceanic crust.

More, Less

As you increase the silica content and decrease the temperature of a magma, it becomes ____ viscous, typiaclly resulting in ____ style eruptions.

More; Explosive

Tephra (cinder) cone

Much steeper, much shorter, a lot of pyroclasts, not much lava, can't pack on pyroclasts for very high-nothing to consolidate it together

____ is the growth of new mineral crystals that differ from those of the parent rock due to chemical reactions

Neocrystalization

Based on Bowen's Reaction series, as you cool a mafic melt, what is the first mineral expected to crystalize?

Olivine

active volcano

One that is erupting or shows signs that it may erupt in the near future.

orogenic belts

Orogeny refers to forces and events leading to a large structural deformation of the Earth's lithosphere (crust and uppermost mantle) due to the interaction between tectonic plates. Orogens or orogenic belts develop when a continental plate is crumpled and is pushed upwards to form mountain ranges, and involve a great range of geological processes collectively called orogenesis. How mountains are built on continents.

Convection of the liquid iron alloy that composed the ___ generates the Earth's magnetic field. It remains molten despite the great pressure due to the extreme heat not allowing atoms to form a solid crystalline structure.

Outer Core

lithostatic overburden

Overburden pressure, also called lithostatic pressure, confining pressure or vertical stress, is the pressure or stress imposed on a layer of soil or rock by the weight of overlying material.

Which two gases compose 99% of Earth's Atmosphere?

Oxygen (O2) and Nitrogen (N2)

Basalt flows whose surfaces are warm and pasty wrinkle into smooth, glassy, rope-like ridges called _____

Pahoehoe

Decompression Melting

Partial melting of hot mantle rock when it moves upward and the pressure is reduced to the extent that the melting point drops to the temperature of the body.

_____ transforms one mineral into another mineral with the same composition but a different crystal struction

Phase Change

When submarine volcanic eruptions occur, the lava is rapidly quenches forming a blob with a glassy rind called a ____

Pillow Basalts

A large body of magma emplaced within the crust is called a _____

Pluton

Two different minerals (like diamond and graphite) that have the same composition but different crystal structures are called _____

Polymorphs

A sedimentary rock composed of gravel-sized clasts with pointed edges in a silt - or clay sized matric would be classified as a _____ and _____

Poorly-Sorted, Angular

The sedimentary deposits formed from glacial activity are typically ____ and ____ called glacial till, due to how ice transports and deposits clasts.

Poorly-Sorted, angular.

Erosion

Processes by which rock, sand, and soil are broken down and carried away (i.e. weathering, glaciation)

A ____ is the "parent" rock that undergoes a solid-state (without melting) transformation in response to changes in pressure and/or temperate.

Protolith

_____ is a felsic volcanic rock that consists of tiny bubles, each of which is surronded by a thin wall of glass that forms from quickly cooling, volatile-rich frothy lava.

Pumice

A fine grain crystalline texture with a glassy groundmass typically results from magamas which cooled ___ and ____ ground

Quickly, Above

____ changes the size and shape of grains without changing the mineral compositon or struction making up the grains, typically resulting in larger, interlocking grains.

Recyrstallization

Scientists call this the expanding universe theory. This is demonstrated by the _______ shift observed in light emitted by distant stars.

Red

formation

Relative disposition of parts.

A large continent can split into smaller ones by the process of ________

Rifting

intermediate rock or magma

Rock with a chemical content between felsic and mafic compositions.

dunes

Sand accumulates when there is an obstruction across the wind path. The more sand gets collected, the steeper the slope will be.

chemical rock

Sedimentary rock that forms when minerals crystallize from a solution

Layering

Separating components of a design individually or into groups in order to make specific adjustments

shear (of rocks)

Shear is the response of a rock to deformation usually by compressive stress and forms particular textures. ... The process of shearing occurs within brittle, brittle-ductile, and ductile rocks. Within purely brittle rocks, compressive stress results in fracturing and simple faulting.

Biochemical sedimentary rock, one of four major sedimentary rock classes, typically consists of ___ and is composed of ____

Shell Fragments, Calcium Carbonate

Volcano Types

Shield, Cinder, Strato

Magmas are broadly classified into four categories based on the ____ weight percentage.

Silica

_____ minerals are the most common crust minerals, composing of >95% of the continental and oceanic crust and most the mantle.

Silicate

Silicate Minerals are distinguished from each other by the ways in which the _____ that compose them are linked or arranged

Silicon-oxygen tetrahedra

What is the feature called where an igneous intrusion is injected parallel to the bedding or layering of the rock?

Sill

______ and _____ forces contribute to driving tectonic plate motions, with some contribution from convection within the mantle.

Slab-Pull, Ridge-Push

List in order of increasing metamorphic grade the foliated metamorphic rocks formed from a shale (pelitic) protolith.

Slate, Phyllite, Schist, Gneiss, Migmatite

ripple marks

Small waves of sand that develop on the surface of a sediment layer by the action of moving water or air.

The Earth's magnetic field deflects the _____ being continuously emitted from the sun that is composed of fast moving, high energy particles.

Solar Wind

intrusive magma

Solidifies at a depth; has a coarse grain. Example is granite

extrusive magma

Solidifies at or near the surface; cools quickly and has a fine grain. Example basalt

The degree to which all clasts in a sediementary rock are the same size or variety of different sizes is referred to as

Sorting

Elements greater than atomic number 5 (boron) are created through a process called ______

Stellar Nucleosynthesis

Large, typically felsic cone-shaped volcanoes with steep slopes composed of layers of lava, tephra/ash and volcaniclastic debris are called

Stratovolcanoes

Stress vs. Strain

Stress is the total force acting on crustal rocks per unit of area Strain is the deformation of materials in response to stress

Compression

Stress that squeezes rock until it folds or breaks

tension

Stress that stretches rock so that it becomes thinner in the middle

Geologists use the term _____ to refer to the process where the surface of the crust sinks over a long period of time, allowing thick piles of sedimentary rocks to accumulate.

Subsidence

Geologist use the term _____ for unconsolidated fragments resulting from an eruption

Tephra

Weathering

The breaking down of rocks and other materials on the Earth's surface.

pyroclastic flow

The expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption

Silica content of magma

The main factor that accounts for the difference between quiet and explosive volcanic eruptions is

exhumation

The process (involving uplift and erosion) that returns deeply buried rocks to the surface.

Recrystallization

The process by which bonds between atoms in minerals break and re-form in new ways during metamorphism.

fractional crystallization

The process by which the crystals formed in a cooling magma are segregated from the remaining liquid at progressively lower temperatures.

chemical weathering

The process that breaks down rock through chemical changes

Lithification

The process that converts sediments into solid rock by compaction or cementation.

metamorphic zone

The region between two metamorphic isograds, typically named after an index mineral found within the region.

Geologists refer to a point where three plate boundaries meet as a ______

Triple Junction

Weather on our planet is limited to what layer of the atmosphere?

Troposphere

Underwater debris flows called ____ leave normally graded deposits due to settling out in water with the larger clasts towards the bottom and the smaller clasts towards the top.

Turbidity currents

Pahoehoe vs. Aa

Two major types of basaltic lava flows: Pahoehoe: very smooth or ropey lava, looks like flowing toothpaste Aa: broken jumbles of sharp fragments with rough edges

The strongest portion of the magnetic field is called the _________, it is located about 3,000 and 10,500 km away from earth and stop high energy cosmic rays.

Van Allen Radiation Belts

flood basalt

Vast sheets of basalt that spread from a volcanic vent over an extensive surface of land; they may form where a rift develops above a continental hot spot, and where lava is particularly hot and has low viscosity.

Volcanic gases come out of a solution as pressure is released while magma is rising during an eruption, the last bubles to form are trapped within the cooling lava generating ____

Vesicles

transporting medium

Water, Wind, Ice

Aeolian procecsses selectively sort clasts based on grain size. Given this information, what sorting characteristics and grain size would you expect sediments in a desert enviornment

Well sorted, sand-sized clasts

How is magma formed?

When Metamorphic or any rock melts it will form magma

Compaction rock

When pieces of a rock are pushed together. If "glue" is there too, a new rock can form.

Assimilated wall rock does not entierely melt within a magma body is called a _______

Xenolith

cement

a building material that is a powder made of a mixture of calcined limestone and clay

phase change

a change from one state (solid or liquid or gas) to another without a change in chemical composition

Diagenesis

a collective term for all the chemical, physical, and biological changes that take place after sediments are deposited and during and after lithification

mantle plume

a column of very hot rock rising up through the mantle

Cratons

a large, stable block of the earth's crust forming the nucleus of a continent.

columnar jointing

a pattern of cracks that forms during cooling of molten rock to generate columns

metamorphic grade

a representation of the intensity of metamorphism, meaning the amount or degree of metamorphic change

Breccias

a rock composed of fragments of earlier rocks bonded together

Schistosity

a type of foliation characteristic of coarser-grained metamorphic rocks; such rocks have a parallel arrangement of platy minerals such as the micas

shield volcano

a wide, gently sloping mountain made of layers of lava and formed by quiet eruptions

explosive eruption

an eruption that is thick and sticky, has a high gas content, and is high in silica

porphyritic texture

an igneous texture consisting of large crystals embedded in a matrix of much smaller crystals

The smoothness or roughness of clasts composing a sedimentary rock is referred to as _____

angularity

Ignimbrites

ash flow tuff

A single layer of sediment or sedimentary rock with a recognizable top and bottom is called a _____

bed

The process where minerals such as quartz and calcite precipitate from groundwater and fill the remaing spaces between clasts is referred to as _____

cementation

types of sedimentary rocks

clastic, chemical, organic, biochemical

Strato Volcano (composite cone)

conical, steep-side, symmetrical volcano (ratio of height to breadth relatively large) composed of alternating layers of silicic lavas and pyroclastics. Typical of subduction zone volcanism.

Viscosity of magma

depends on its silica content and temperature

Deltas

deposits of sand and soil at the mouth of a river form

Mafic

describes magma or igneous rock that is rich in magnesium and iron and that is generally dark in color

aphanitic texture

fine grained

foliated vs non-foliated

foliated has a banded appearance and particles that align evenly. non-foliated has particles that are scattered.

The parallel alignments of platy or elongate minerals in response to a differntial stress is called _____

foliation

mud cracks

form when fine-grained sediments at the bottom of a shallow body of water are exposed to the air and dry out

regional metamorphism

formation of metamorphic rock bodies that are hundreds of square kilometers in size

pyroclastic debris

fragmented material that sprayed out of a volcano and landed on the ground or sea floor in solid form

Volatiles

gaseous components of magma dissolved in the melt. They will readily vaporize at surface pressures

pillow basalt

glass-encrusted basalt blobs that form when magma extrudes on the sea floor and cools very quickly

Turbidity currents generate

graded bedding

Turbidites

graded layers of terrigeneous sand interbedded with finer pelagic sediments of the deep sea floor

The diameter of clasts composing a sedimentary rock is referred to as _______

grains sizeang

metamorphic facies

groupings of metamorphic rocks of various mineral compositions formed under different grades of metamorphism from different parent rocks

phaneritic texture

igneous rock texture in which minerals are easily visible without magnification

felsic magma

magma with a high silica content and large volume of gas (explosive eruptions)

The continental shields consist mostly of

metamorphic and igneous rocks

pressure solution

metamorphic formation process; happens when a rock is squeezed more strongly in one direction that in others at relatively low pressures and temperatures, in the presence of water. Mineral grains dissolve where their surfaces are pressed against other grains, producing ions that migrate through the water to precipitate elsewhere.

thermal metamorphism

metamorphism caused by heat conducted into country rock from an igneous intrusion

burial metamorphism

metamorphism due only to the consequences of very deep burial

dynamic metamorphism

metamorphism that occurs as a consequence of shearing alone, with no change in temperature or pressure

index materials

minerals that form within specific temperature and pressure ranges during metamorphism

hydrothermal metamorphism

occurs when very hot water reacts with rock, altering its mineralogy and chemistry

strata (beds)

parallel layers of sedimentary rock

Lapilli

pebble like bits of magma that cool in the air

plastic deformation

permanent change in shape by bending and folding

crustal subsidence

regions once covered by ice during the last ice age were uplifted when all ice was gone

Small, elongated ridges that form on a bed surface at right angles to direction of current flow (water/wind) are called ______

ripple marks

organic rock

sedimentary rock that forms from remains of organisms deposited in thick layers

clastic rock

sedimentary rock that forms when rock fragments are squeezed together under high pressure

biochemical rock

sedimentary rock that was formed by organisms or contains the remains of organisms

Sills

sheetlike intrusions that are oriented parallel to previous rock units

bedding plane

the boundary between two beds

shock metamorphism

the changes that can occur in a rock due to the passage of a shock wave, generally resulting from a meteorite impact

angularity

the degree of edge or corner smoothness

Heat Transfer

the flow of thermal energy from higher temperature to lower temperature

igneous activity

the formation, movement, and in some cases eruption of molten rock

deposition (of rocks)

the geological process in which sediments, soil and rocks are added to a landform or land mass

Groundmass

the matrix of smaller crystals within an igneous rock that has porphyritic texture

Protolith

the original rock from which a metamorphic rock formed

magma chamber

the pocket beneath a volcano where magma collects

Metasomatism

the process by which a rock's overall chemical composition changes during metamorphism because of reactions with hot water that bring in or remove elements

partial melting

the process by which different minerals in rock melt at different temperatures

Stratification

the process in which sedimentary rocks are arranged in layers

magma mixing

the process of altering the composition of a magma through the mixing of material from another magma body

geothermal gradient

the rate of change in temperature with depth

Fossils

the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.

Bowen's Reaction Series

the simplified pattern that illustrates the order in which minerals crystallize from cooling magma according to their chemical composition and melting point

types of metamorphism

thermal, burial, dynamic, regional, hydrothermal, subduction, shock

When relative sea level drops and the shoreline migrates seaward, this process is called _____

transgression

Lahars

volcanic mudflows

Evaporties

when the water in these seas or lakes evaporates, deposits of salts are left behind

Calderas Volcanoes

• Large • Explosive • Felsic pyroclastic material. • magma chamber roof collapses Ex: Yellowstone, Crater Lake