Geology final exam 1103

The Richter scale for earthquakes is an exponential scale, meaning the Japanese 2011 earthquake of magnitude 9 was how many times stronger than the Haitian 2010 earthquake of magnitude 7:

100

A mineral is defined as:

A naturally occurring solid crystalline substance, generally inorganic, with a specific chemical composition.

An example of eolian (wind) deposits transported as a suspended load in Louisiana is:

A. Loess deposits on the east side of the Mississippi River

Potholes in the bedrock of rivers are primarily formed by:

Abrasion by smaller rocks inside the pothole

The North American craton is composed of:

An ancient continental shield and interior platform

The wavy line between E and the group ABCD is called :

Angular unconformity

Alfred Wegener developed what concept that led to the Theory of Plate Tectonics:

Continental Drift

A blueschist rock indicates______ metamorphism typical of ________.

High pressure, low temperature / subduction zones

The mineral olivine :

Is an isolated tetrahedral silicate mineral

The process that moves rock and soil downhill under the influence of gravity is called

Mass wasting or mass movement

Climate variations caused by variations in the Earth's orbit around the sun and the tilt of its axis are called

Milankovitch cycles

False River is an example of a:

Oxbow lake / cut off meander

At divergent plate boundaries:

Plates move apart and new lithosphere is created.

A debris flow, such as the one from the Andes mountains in the video

Rapidly moves large quantities of rock downhill, primarily under the force of gravity

From the above diagram, what size type of sediment would be eroded at the level of the blue line, and what could be deposited?

Sand /Gravel

Major annual flooding of the Mississippi River at Baton Rouge is most associated with:

Snow melt in the Rocky Mountains

20th century observations (1920's to 1960's) along mid-ocean ridges went against older notions of the nature of the ocean because:

The ocean was shallower in the middle than along the sides of the ocean There was almost no sediment in the middle of the ocean The seafloor was youngest in the middle and composed of volcanic rock

The sweet spot to build a sand castle at the beach is:

Where the sand is just damp, because there is enough capillary attraction to hold the sand together

During metamorphism, a rock undergoes mineralogical and textural changes:

While primarily in a solid state, due to changes in heat and/or pressure.

A depositional feature found at the end of a glacier where it has melted and deposited sediment is called a:

Moraine

Basaltic lava flows in Hawaii that move like oozing molasses and form a smooth, ropey surface are called:

Pahoehoe

The Base Level of a stream is:

The elevation at the end of a stream where it enters a large standing body of water, such as a lake or ocean

The three axes of the metamorphic rock diagram should be labeled:

A= Pressure, B=Temperature, C= Depth

A permeable and porous geological stratum that can store and transmit enough groundwater to sustain water supply wells is:

An aquifer

The maximum angle at which a slope of loose material will lie without sliding is called

Angle of repose

In a river delta, smaller channels that branch off from the main channel and flow into receiving water bodies are called:

Distributaries

Natural land loss in the Mississippi River delta area is due:

Growth faulting Compaction of older delta sediments Erosion of abandoned deltas

A spring tide:

Happens when the Sun and the Moon line up relative to the Earth's oceans

According to the __________, earthquakes occur when ___________ accumulates until it exceeds the strength of the rock.

Elastic Rebound Theory / stress

A type of metamorphism created by the intrusion of an igneous dike at into shallow pre-existing rock is called:

Contact metamorphism

The tectonic boundaries with the deepest focus earthquakes would be:

Convergent boundaries

Major earthquakes of magnitudes greater than 8 on the Richter scale are typically related to:

Convergent plate boundaries Subduction zones The Pacific "Ring of Fire"

A barchan sand dune is:

Crescent shaped, with its points facing downwind

The geologic history of this sketch can be summarized in order by:

Deposit A through D, Uplift / Deformation, Erosion, Deposit E through G, Intrude volcanic dike

We interpret the sedimentary environment that formed the sandstone in the cliffs of Zion Canyon as:

Desert sand dunes because they are identical to modern sand dune sedimentary structures

If a rock body is subjected to a force, and it deforms by breaking or faulting, that represents ______________ deformation

brittle

Which of the following is not a mineral?

coal

Which of the following alluvial sedimentary environments would be the most likely area for early settlers in Louisiana to use for cultivation:

natural levee

Carbon-13 has six (6) protons. Therefore, this carbon isotope has how many neutrons in its nucleus?

7

A fjord is :

A glacial valley that is flooded by the ocean

Quartz is:

A hard, framework silicate mineral, with conchoidal (glass-like) fracture

In a sequence of sedimentary strata, an unconformity represents:

A missing interval of time, during which sedimentary rocks were either eroded or not deposited

Granite rocks that form mountains on continental crust (and are favorites for counter tops!) are what types of igneous rocks:

Felsic / Intrusive

Lake Pontchartrain was formed by:

The deposition of the St. Bernard delta to the south

If an igneous rock contains mostly quartz, it's composition is considered to be:

Felsic

Coarse-textured igneous rocks have large crystals because:

They have cooled slowly.

Cheniers are:

the high ground along the western coast of Louisiana that early settlers could develop Arcuate shaped, beach ridges along the southwest Louisiana coast

The present location that Louisiana now occupies is or was at one time in the past:

A divergent plate margin when Gondwanaland broke away from North America A convergent continental - continental margin during the assembly of Pangea An open oceanic setting on a passive continental margin

Pangea is a name for:

A former supercontinent that was made up of all present continents

The United States mainland is characterized by which of the following tectonic margins:

A transform margin characterized by frequent strong earthquakes A Passive continental margin characterized by deep sedimentary deposits A convergent margin with deep sea trench and volcanoes on the mainland

In which of the following locations would one most likely find an alluvial fan:

At the mouth of a mountain canyon

Diamond is the hardest mineral on the Mohs Scale of Hardness because:

B. It has covalent bonding in a 3 dimensional framework

The type of lava that forms at the highest temperatures is:

Basalt

What volcanic rock type would spread out a long distance from its source, compared to other lavas?

Basalt, because it has a lower viscosity than other lavas

Oceanic crust always subducts below continental crust because it is:

Composed of denser rocks

Seismic P waves are also known as:

Compression waves

A thrust fault indicates that the rocks were deformed under what type of force:

Compressional

The names of the appropriate metamorphic rocks in the correct places in the chart from the following choices below should be:

D= Slate, E= Schist, F= Gneiss

Evidence for a warming trend in the global climate is:

Declining Arctic sea ice coverage Rising sea levels Retreat of glaciers

A cone- or fan-shaped accumulation of sediment deposited where a stream enters a large standing body of water, such as where the Mississippi River enters the Gulf of Mexico, is a(n):

Delta

Barrier islands along the Louisiana coast were formed by:

Erosion at the seaward margin of former delta fronts

Which of the following statements about the explosiveness of volcanic eruptions is true?

Explosiveness increases as the silica content of the lava increases

Igneous rocks with very small / microscopic crystals or that are mostly glass are typically:

Extrusive igneous rocks

The atoms that compose the heavier elements in the Earth were formed:

From nucleosynthesis in former stars that have gone through a supernova event

Geology is different than physics or chemistry because:

Geology is a diachronous science, so the geological record has been unique through time in any one location

The position of the coast of Louisiana has changed through time due to:

Growth faults have dropped down large blocks of land below sea level along the coast of the Gulf of Mexico Rivers that built deltas out on a passive continental margin Sea level fluctuations during glacial ages

Geology / Earth Science:

Is a process of observing contemporary Earth materials and the rock record; creating and testing hypotheses to explain the processes that form these different rocks types; and relating these to the development of the Earth through time.

A braided stream has the following characteristics:

Multiple channels flowing at the same time No single, dominant channel High sediment load, high velocity

Where an angular unconformity exists, the bedding planes of sedimentary strata above and below the unconformity are:

Not parallel to each other

A geophysicist can determine the distance between a seismograph and an earthquake's epicenter by measuring the elapsed time between the arrival of the ______ and ______ at a seismograph.

P waves and S waves

At convergent plate tectonic margins:

Plates come together and oceanic crust is recycled back into the mantle.

Which of the following is considered part of a stream's bed load?

Saltating sand grains and gravel

The transportation process of sand grains by water by moving them along in a series of short intermittent jumps is:

Saltation

The hillslope that crosses College Drive just south of the BRCC campus and east of the I-10 was formed by:

The offset due to a growth fault

We can reconstruct the continental drift pattern between North America and Gondwanaland by

The pattern of sea floor magnetic isochrons in the North Atlantic

The principle stating that an identical sequence of fossils identified in separate locations is time equivalent is:

The principle of faunal succession

Relative ages of rocks may be determined using:

The principle of original horizontality The principle of cross-cutting relationships The theory of faunal succession

Banded iron formations are important because:

They are a sedimentary rock record of the oxygenation of the oceans by the development of photosynthetic plants They are an important source of iron ore They help build the steel industry of the US

The Southern Hills and Chicot aquifers are important to Louisiana because:

They provide abundant drinking water to Baton Rouge They provide irrigation water to the rice crops and crawfish farms of the Acadia region They provide groundwater for industries in Lake Charles

What is not a major control of climate in any region?

Variation in the orbit of the Earth around the Sun The flow pattern of oceanic currents . Variation in the energy from the Sun.

How do geomagnetic isochrons on the ocean seafloor indicate where there is a faster rate of spreading at a mid-ocean spreading center than others:

Where isochrons are wider and farther apart

Which of the following terms describes a curved, coarse-grained sand deposit that forms on the inside curve of a stream channel?

point bar

Which of the following alluvial sedimentary environments is where the dominant sedimentary deposits are clay size?

floodplains

The actual location on a fault plane where the rupture occurs that causes an earthquake is called the:

focus

Which of the following materials is least likely to be transported as suspended load:

gravel

Clay deposits are lithified into rock called:

shale