Holy moly

Which of the following igneous rocks crystallizes at or near the Earth's surface?

a) rhyolite

b) gabbro

c) granite

d) peridotite

a) rhyolite

Sandstone, siltstone and shale are?

a) clastic sedimentary rocks

b) organic sedimentary rocks

c) chemical sedimentary rocks

d) meramorphic rocks

a) clastic sedimentary rocks

A flexural basin is formed at what type of plate boundary?

a) divergent

b) convergent (ocean - ocean)

c) convergent (ocean - continent)

d) transform

c) convergent (ocean - continent)

The parent rock of a quartzite is a _____.

a) granite

b) limestone

c) shale

d) sandstone

d) sandstone

Piles of talus at the base of cliffs in high alpine areas are likely the result of:

a) chemical weathering

b) pressure relief fracturing

c) abrasion

d) frost wedging

d) frost wedging

What is the correct metamorphis sequence of increasing degrees of metamorphism?

a) phyllite > slate > schist > gneiss

b) gneiss > schist > slate > phyllite

c) slate > phyllite > schist > gneiss

d) schist > gneiss > phyllite > slate

c) slate > phyllite > schist > gneiss

The ____ is the maximum slope, or steepness, at which loose material remains stable.

a) dip slope

b) mass wasting angle

c) angle of repose

d) slip slope angle

c) angle of repose

One hypothesis proposes that large igneous provinces form at hot spots by mantle plumes that originate at what boundary within the Earth?

a) crust - mantle

b) mantle - outer core

c) outer core - inner core

d) mantle - lithosphere

b) mantle - outer core

What is molten rock beneath the Earth's surface called?

a) granite

b) lava

c) batholith

d) magma

d) magma

Which of the following is not a pyroclastic material?

a) rock

b) ash

c) lava

d) cinders

c) lava

In a flow:

a) material free falls

b) material moves as a coherent mass

c) particles are greater than sand size

d) particles move independently of one another

d) particles move independently of one another

Which of the following statments about transportation of sediments is false?

a) Smaller particles settle faster than larger particles

b) as a current slows, the largest particles settle first

c) faster currents can carry larger particles than slower currents

d) river and ocean currents move much more material than air currents

a) Smaller particles settle faster than larger particles

During ____, water dissolves a mineral to form a solution.

a) dissolution

b) hydrolysis

c) frost wedging

d) salt cracking

a) dissolution

In a meandering stream, where are sediments being deposited?

a) along both sides of the channel

b) along the bottom of the channel

c) along the outside of the curve

d) along the inside of the curve

d) along the inside of the curve

Where do atolls form?

a) on beaches along active continential margins

b) on subsiding volcanic islands

c) on tidal flats in humid environments

d) on wave-dominant deltas

b) on subsiding volcanic islands

Which type of volcano is the largest?

a) shield

b) stratovolcano

c) caldera

d) cinder cone

a) shield

Basaltic lava that cools quickly underwater forms distinct ___ features.

a) pillow lava

b) basalt dikes

c) sills

d) gabbro

a) pillow lava

Mechanical weathering

a) reduces solid rock into small fragments by altering the chemical composition of rocks and minerals

b) reduces solid rock to small fragments without altering the chemical composition of rocks and minerals

c) causes iron minerals to rust

d) picks up can carries off weathered rocks and minerals

b) reduces solid rock to small fragments without altering the chemical composition of rocks and minerals

Foliation in a metamorphic rock is oriented

a) perpendicular to the direction of the greatest compression

b) parallel to the direction of the greatest compression

c) perpendicular to the direction of streatching

d) parallel to the original bedding

a) perpendicular to the direction of the greatest compression

The least soluable mineral in granite is

a) calcite

b) feldspar

c) quartz

d) mica

c) quartz

Rust is an example of

a) dissolution

b) hydrolysis

c) exfoliation

d) oxidation

d) oxidation

Which of the following types of sandstones is composed mostly of feldspar grains?

a) arkose

b) graywacke

c) quartz arenite

d) litharinite

a) arkose

During a ____, a coherent block of material fractures and moves downslope.

a) slide

b) fall

c) flow

d) slump

a) slide

All of the following are factors that affect rates of weathering except for

a) rock properties

b) surface area

c) climate

d) geologic age

d) geologic age

Large igneous bodies greater than 100 km2 that form at depth in the earths crust are called?

a) dikes

b) plutons

c) sills

d) batholiths

d) batholiths

The retrograde part of a metamorphic P-T path occurs duning

a) burial and cooling

b) exhumation and cooling

c) burial and heating

d) exhumation and heating

b) exhumation and cooling

In the weathering process of pressure-release fracturing:

a) salts crystallize in cracks enlarging fractures

b) bedrock minerals decompose to clay

c) bedrock expands and fractures when the overlying rock is removed

d) bedrock dissolves and groundwater carries the dissolved ions away

c) bedrock expands and fractures when the overlying rock is removed

Abrasion of sediment particles results in which of the following?

a) they become smaller and more angular

b) they become smaller and more rounded

c) they become smaller and heavier

d) they become larger and more angular

b) they become smaller and more rounded

Blueschists are characteristic of which tectonic setting?

a) mid ocean ridges

b) transform boundaries

c) subduction zones

d) continential collisions

c) subduction zones

A litharanite is a

a) sandstone composed mostly of quartz and feldspar

b) sandstone composed mostly of rock fragments

c) shale composed mostly of very fine grained quartz and feldspar

d) conglomerate composed mostly of quartz and rock fragments

b) sandstone composed mostly of rock fragments

Which of the following pairs of intrusive and extrusive rocks have the same chemical composition?

a) diorite and rhyolite

b) gabbro and rhyolite

c) granite and rhyolite

d) granite and basalt

c) granite and rhyolite

What type of rock makes up the Columbia Plateau of Oregon and Washington?

a) cinder cones

b) flood basalts

c) pyroclastic flows

d) granite

b) flood basalts

Which of the following is not a chemical weathering process?

a) salt weathering

b) hydrolysis

c) oxidaton/reduction

d) hydration

a) salt weathering

Which of the following igneous bodies is a horizontal, tabular, concordant intrusive rock?

a) dike

b) pluton

c) sill

d) batholith

c) sill

Which rock would make the longest lasting tombstone marker?

a) limestone

b) slate

c) granite

d) sandstone

c) granite

Marble is a metamorphic rock that forms from _____

a) granite

b) limestone

c) sandstone

d) shale

b) limestone

Which of the following forces is the dominant cause of mass movements?

a) gravity

b) earthquakes

c) volcanoes

d) frost wedging

a) gravity

What is the name for a basaltic lava flow that has a ropy, folded surface?

a) aa

b) breccia

c) pahoehoe

d) tuff

c) pahoehoe

Weathering is the decomposition and disintergration of rock and minerals at the Earth's surface by:

a) both mechanical and chemical prosesses

b) chemical processes only

c) mechanical processes only

d) internal processes

a) both mechanical and chemical prosesses

Which of the following statements are true?

a) cementation increases porosity, whereas compaction decreases porosity

b) cementation decreases porosity, wheras compaction increases porosity

c) cementation and compaction both increase porosity

d) cementation and compaction both decrease porosity

d) cementation and compaction both decrease porosity

The parallel allignment of mica in a metamorphic rock is an example of ___

a) bedding

b) foliation

c) metasomatism

d) porphyroblasts

b) foliation

On a delta, where are the finest sediments deposited?

a) at the mouth of the river

b) at the furthest extent of the delta

c) along the stream channel

d) they are deposited evenly throughout

b) at the furthest extent of the delta

Which type of volcano erupts the most violently?

a) shield

b) cinder cone

c) stratovolcano

d) caldera

d) caldera

Granite commonly fractures by

a) salt cracking

b) exfoliation

c) chemical weathering

d) none of these

b) exfoliation

In which of the following sedimentary enviroments would gravel most likely be deposited?

a) alluvial

b) continental shelf

c) deep-sea

d) deltaic

a) alluvial

The rock formed by the low grade metamorphism of a slate is

a) gneiss

b) phyllite

c) schist

d) shale

b) phyllite

Wind, flowing water, glaciers and gravity are

a) agents of weathering

b) agents of isostasy

c) agents of erosion

d) agents of orogeny

c) agents of erosion

What type of sediments are accumulations of solid fragments produced by weathering?

a) biochemical sediments

b) clastic sediments

c) chemical sediments

d) all of the above

b) clastic sediments

Comglomerate and breccia differ in and can be readily distinguished by:

a) grain size

b) mineral composition

c) grain roundness

d) abundance of rock fragments

c) grain roundness

What type of metamorphism is caused by high temperature and high pressure imposed over a large volume of crust, for example, by collisions of plates?

a) burial

b) contact

c) regional

d) shock

c) regional

Rock

Common, naturally occurring assemblage of at least 1 mineral, compacted/consolidated

Problems with rock definition

Obsidian (glassy volcanic rock)

Coal (sedimentary rock made of organic material)

Intrusive igneous rock

rock that cools under the crust, slower so allows more crystals to grow

Intrusive silica content high to low

Granite, diorite, gabbro

Extrusive igneous rock

rock that cools above the crust, cools very fast so fine grained crystals

Extrusive silica content high to low

rhyolite, andesite, basalt

Basaltic Lava

flows ready and fast, oceanic crust

Andesitic Lava

medium silica content, sticky, smooth peanut butter, can plug up and explode

Rhyolitic Lava

more complex silicate, crunchy peanut butter

Ejecta

ash and bomb, forms tuffs and breccias

Flows

hot expanding gas lifts density flow of ejecta

Pahoehoe

ropy lava that spreads in sheets and forms "skin", close to vent

Aa

blocky, less gasses so more viscous, farther from vent

Aphanitic

crystals too small for human eye

Phaneritic

mineral crystals large enough to be viewed unaided

Porphyry

large grained crystals in fine grained mixture

Rock formed at crust

Rhyolite

large igneous province (LIP)

Layers of flood basalts, 1 event can erupt as much lava as the ocean ridge system's annual output

Shape of LIP

Mantle plume, head, tail

LIP lava type

basaltic

What produces volcano change?

LIP, plates move but jet doesn't

Kileaua eruption length

65M years or more b/c subduction zone eats away

Ocean crust layers

Magma, Peridotite, Gabbro, Sheeted Basalt (dikes)

Differential melting/cooling

crystals settle out of magma layer, forming peridotite layer

Fissure Eruption

Highly fluid basalt flows readily away from vent, forming widespread layers

Ocean-ocean magma source

ocean crust and sediments

Continent-ocean magma source

mix of oceanic and continental crust and sediments

Fluid-induced melting

Ocean layer subducted, trapping water that heats up and melts overlying plate when released

Shield volcanoes

Fluid basalt (low silica content), gentle slope, large diameter, many many layers

Shield volcanoes examples

Mauna Kea, Mauna Loa, Iceland

Cindercones

Formed by pyroclastic fragments, steep and symmetrical small cone, no flowing lava

Cindercone example

Cerro Negro

Pyroclastic material

stuff that gets shot up in the air by the volcano

Composite cones/Stratovolcanoes

"typical" volcano, steep sided profile, snow, erosion resistant, lava and pyroclastic material, sheet dikes form and add stability, andesitic/basaltic lava

Stratovolcano examples

Mt. St. Helens, Mt. Vesuvius

Caldera

collapsed, evacuated magma chamber; steep-walled; circular; 40+ km diameter; gas comes up through fractures and then the ground collapses in

Caldera Example

Yellowstone (3)

Pyroclastic Flows

column of pyroclastic materials and gas fall to ground; Nuee ardente (glowing cloud); hot, fast, and far reaching; 30-200 m/s

Ash flow tuff

post flow the ash may weld/compact into a solid mass

Tuff example

Yosemite's Long Valley (Bishop Tuff)

Ash flow example

Mt. Vesuvius

Regional prediction

areas most likely

- subduction zones

- spreading centers

- hot spots

Violence

related to crustal domain

- continental (granitic/intermediate) - more violent

- basaltic - tend to be less violent

Short-term prediction

looking for time and place of eruption

- changes in shape

- earthquake swarms

- gas/ash emission

- temperature anomalies

Volcanoes and global cooling

ash and sulfur clouds reach high altitudes, reflecting solar radiation

Global cooling example

Pinatubo, 1991; solar radiation reaching Earth declined by 2-4%

Volcanoes and global warming

Eruption releases carbon dioxide gases, warming the earth

Global warming example

Permian extinction, 225 mya; 90% marine species and 65% reptile and amphibians, siberian flood basalts

Weathering

A major geologic process in the rock cycle that shapes the Earth's surface and converts all kinds of rocks into sediment and forming soil

Erosion and Transport

Processes that loosen and transport soil and rock downhill/downwind/downstream