GEOL 102 EXAM 2 Study

Earth’s Structure

crust, mantle, outer core, inner core.

hyperthermophiles

Microorganisms that live in high-temperature environments; some of them are chemoautotrophs

Shield

A region uplifted and exposing crystalline basement of Precambrian age (> 2.5 billion years) and undeformed during the past 500 Ma

Platform

A region where flat layering sediments overlie platform basement rocks

Continental Basin

a region of prolonged subsidence where thick sediments have accumulated

Orogen

region where mountain building has been active

Extended Crust

region where recent deformation has involved large-scale extension

Large igneous province

large outpouring of basalt

Faults

are fractures in rocks created by tectonic processes where there has been relative movement of the rock on both sides of the fault

When doo we start seeing unconformities?

with regression

What are pieces of the mantle or lower crust brought up by volcanic eruptions called?

Xenoliths

Order of rock in Frenchman Mountins

Tapeats Sandstone → Bright Angel Shale → Muav Limestone

Scientists use ____ to study the layers of the Earth.

indirect methods

Density

mass/volume; the greater the density of the material, the slower the P-waves travel.

Rigidity

is how strongly the material resists being bent sideways and is able to straighten itself out once the shearing force has passed • The more rigid the material, the faster the P-waves • Solid rock is more rigid than loose soils

Compressibility

is how much the material can be compressed into a smaller volume and then recover once the compressing force has passed • The more compressible the material, the faster the P-waves.

Which part of the Earth does not transmit S-Waves?

Outer Core

Which response is good evidence that the Earth’s inner core is solid rather than liquid?

P waves move faster through the inner core than the outer core

What was the reason for the decline of stromatolites?

rise of other organisms, has to be in a shallow marine environment

How do we identify glaciers within the proterozoic era

striations, not fossils.

Greenville orogeny is related to the formation of what supercontinent?

Rodinia

What are redbeds regarded as

show oxidation of minerals, carbonates forming

Xenolith

foreign piece of rock, pieces of mantle brought up with volcanic intrusions/eruptions.

P Waves

primary waves, travel through solids and liquids (fastest).

S waves

Secondary Waves - only travel through solids.

Hypocenter (focus)

The location where fault slip occurs. it is usually on a fault surface.

Moho

The crust-mantle boundary

Where is the moho located?

lithosphere

Which wave travels the fastest?

P-wave

What is it called when an abrupt change in seismic wave velocity takes place at the base of the crust?

Moho Discontinuity

Which rock type is inferred to make up the mantle?

preidotite

Which of the following is not a type of plate boundary - transform, convergent, divergent, subduction

subduction

The San Andreas Fault in California is an example of which type of plate boundary?

transform, right -lateral strike slip fault

The Himalayas were formed as a result of which type of plate interaction?

Continental-Continental Convergence

In normal faults, the hanging wall moves __.

down

What is the main difference between diorite and andesite?

Texture

Many regionally metamorphosed rocks were once

roots of tall mountains

Thick sequence of sedimentary rocks can accumulate where?

a basin subsides with the accumulation of sediments

The location, thickness, and some properties of the Earth's internal zones may be determined studying.

seismic waves

Plate tectonic movement of the lithospheric plates may be based in part on large thermal convection cells in the Earth’s

asthenosphere

The igneous rock that makes up much of the oceanic crust is

basalt and gabbro

What is the contour interval of this map?

25 feet

What is the approximate elevation of Green Lake?

125-150 feet

To the left is a small portion of a topographic map showing a road and a creek (blue-green line) in Carkeek Park in Seattle.  North is always toward the top of topographic maps such as this

Using the "Rule of V's" determine which way is the creek flowing.

north-to-south

From which direction would it be easiest to climb from the shore to the top of Blake Island?

From the Northeast

What is the elevation difference between the two red arrows?

25 feet.

Which of the following lists of planets are in correct order, from the sun to space.

Mercury, Venus, Earth, Mars

What is a Wilson Cycle?

Opening and closing of ocean basins

Which of the following is false regarding BIFs?

Occurred during a time when photosynthesis did not occur.

Evidence of an iron core generating a magnetic field dates back to __________.

3.4 billion years ago

The Moon is thought to be __.

formed by a collision of the Earth with and object of Mars size

The Earth’s initial crust is composed of

komatiites

Proterozoic was a time of continent building. Which of the following was the Earth’s first known large continent?

Nuna

The Wopmay Orogen recorded what type of event?

Wilson Cycle

Red Beds are regarded as evidence for __.

sustained free oxygen in the atmosphere

Where did much of the initial oxygen produced by photosynthesis end up?

bonded to iron.

LVZ

lower velocity zone in the upper mantle

Asthenosphere

located below the lithosphere and is weak, hot, and ductile. Flows plastically.

Lithosphere

strong, rigid and cold, includes the crust and part of the upper mantle.

Continental Drift

proposed by Alfred Wegener, suggests that continents were once joined together in a single supercontinent called Pangea.

Paradigm Shift to Plate Tectonics

occurred with developments with bathymetry, paleomagnetism, seafloor spread, and earthquake and volcanic activity.

Convergent Boundaries

plates move towards each other, features mountain building, deep earthquakes, volcanism.

Slab pull

the mechanism driving subduction.

Divergent Plate Boundaries

plates move away from each other, features seafloor spreading at mid ocean ridges, shallow earthquakes, volcanism, rift valleys

Transform Boundaries

plates slide past each other horizontally, results in strike-slip faults, shallow earthquakes.

Mantle Plumes

narrow, rising columns of hot, buoyant rock originating from deep within the Earth’s mantle.

Contour Lines

joining point of equal height above or below sea level

Contour interval

The amount of elevation change between adjacent contours

Strike

compass direction of a rock layer as it interacts with a horizontal surface

Dip

acute angle between the rock layer and the horizontal surface measured perpendicular to strike.

Solar Nebula Theory

formation of our solar system; process began with cold cloud of gas and dust which contracted rotated and flattened into a disk like shape.

Terrestrial Planets

are in the inner part of our solar system

Gas planets

outer part of our solar system

Early Atmosphere

formed through processes related to the planet’s accretion and early geological activity; primitive atmosphere derived from gases associated with the comets and meteorites that accreted to form the Earth. Composed of Hydrogen, helium.

Boring Billion

very little change in the atmospheric evolution.

Prokaryotes

lack a nucleus, unicellular, reproduce asexually by simple cell division. shown little evolutionary change for more than 2 billion years

Eukaryotes

reproduce sexually through the union of an egg and sperm; bigger, more complex, and larger than prokaryotes.

BIFs (Banded iron Formations)

units of sedimentary rock with alternating layers of iron-rich material and chert; photosynthesis was vigorous operation at the time they were deposited. Suggest an oxygen poor atmosphere.

Red Beds

sedimentary rocks with iron oxide cements, including shales, siltstones, and sandstones. Considered evidence for free oxygen in the proterozoic atmosphere.

Rock Record

provides information about earth’s past environments

Stromatolites

organo-sedimentary structures built by photosynthetic cyanobacteria in shallow warm water. Among earliest evidence of life. Indicate aquatic environments.

Ooids

round carbonate concretions form in agitated shallow seawater where back-and-forth wave action causes precipitation of carbonate around a nucleus. Indicate high-energy, shallow marine environments with strong currents and wave activity.

Glacier evidence and deposits

indicate periods of significantly colder global or regional climates; ice ages; deposits show striations, poorly sorted deposits containing a mixture of boulders in a mud matrix.Striations and polish on bedrock, formed by the movement of glaciers over the rock surface(evidence of ice flow)

Sauk Sequences

Neoproterozoic-Early Ordovician; represents major transgression

Tippecanoe Sequences

Formation during Ordovician - major transgression

Kaskaskia Sequences

Devonian-Early Carboniferous

Abasroka Sequences

Mid Carboniferous-Triassic

Wopmay Orogeny

NW Canadian Shield; 2.3-2.1 Ga

Greenville Orogeny

Eastern N. America and Canada; ~1.1 Ga; formation of supercontinent rodina

Taconic Orogeny

Mid Ordovician formation; Eastern margin of N.America

Caledonian Orogeny

Silurian-Devonian formation; NW border of Europe

Antler Orogeny

Late Devonian- Pennsylvanian formation; Western N. America

Nuna Supercontinent

~1.8-1.4Ga; break up in Mesoproterozoic; Wilson Cycle

Rodinia Supercontinent

~900 Ma Broke up ~750Ma; Occurred during the Tippecanoe sequence

Pannotia Supercontinent

~650 Formation; broke up during the cambrian; Wilson Cycle

Pangea Supercontinent

~Late Carboniferous-Early Permian formation; Laurussia and Gondwana collide

Which part of the Earth does not transmit s-waves?

outer core