Geology 101 Exam Questions

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

- A divergent plate margin when Godowanaland broke away from north america - A convergent continental margin during the assembly of Pangea - An oceanic setting on a passive continental margin

A braided stream has the following characteristics

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

Two types of magmatic intrusions:

- Plutons, batholiths, stocks, sills, and dikes

Geological evidence for global warming:

- Retreat of glaciers throughout the world - Reduction of Arctic Ocean sea ice - Thinning of arctic permafrost

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

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

Global glaciation conditions can be influenced by:

- Variation in the energy from the sun - Milankovich cycles - Arrangement of continents

Land loss in the Mississippi river delta is due to a combination of:

- reduced sediment load from upriver - growth faulting - compaction of older delta sediments

Supporting evidence for continental drift:

- the jigsaw puzzle fit of the continents - Fossils of the same reptile mesosaurus are found in both south america and africa

Alfred Wegner

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Hugo benioff

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J. Tuzo Wilson

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Vine and Mattewss

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Magma differentiation may happen by:

1. Fractional crystallization 2. minerals selectively settling out of the liquid part of the magma 3. Crystallization through Bowen's Reaction series

Carbon-14 has 6 protons. Therefore, this carbon isotope has how many neutrons in its nucleus?

8

Quartz is:

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

A mineral is defined as:

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

The Atlantic mid-ocean ridge is a type of:

Divergent Margin

An antecedent stream:

Flows over a different landscape than when the stream first formed

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

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

A large intrusion of magma would form a:

Granite batholith

The part of the floodplain immediately adjacent to the channel that is flooded when a stream initially floods over its banks, depositing silt and sand from the main channel and building up an elevated land form at the edge of the channel is a:

Natural Levee

Early settlers in Louisiana most likely used what alluvial sedimentary environments?

Natural levee

An island arc is where:

Oceanic crust subducts beneath another oceanic plate and forms volcanic islands

According to Bowen's reaction series, the first mineral to crystalize out of a melt are:

Olivine and Calcium-rich feldspar

False River is an example of:

Oxbow lake/ cut off meander

At convergent margins:

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

What occurs at divergent plate boundaries?

Plates move apart and new lithosphere is created

At transform fault boundaries:

Plates move horizontally past each other

A curved, coarse-grained sand deposit that forms on the inside curve of a stream channel?

Point bar

Milankovich cycles describe:

Position and orientation of the Earth relative to the sun

What type of drainage network would you expect to find on a volcano:

Radial drainage

The Mississippi river delta is described as a 'birds foot' delta with long distributary channels reaching into the gulf because it is what?

River dominated delta

Which of the following is considered part of a stream's bed load? - dissolved salts - saltating sand grains - potholes - suspended clay particles

Saltating sand grains

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

Saltation

Basaltic lavas usually form what type of landform?

Shield volcanoes

What mass movements slide along a near vertical fault plane and scarp on the up slope side and migrates as a more or less intact mass rather than getting all mixed up?

Slump

Major annual flooding of the Mississippi river in Baton Rouge is associated with:

Snow melt in the rocky mountains

The most devastating phenomenon of a hurricane in a coastal region is:

Storm surge

Andesitic lavas usually form what landforms?

Stratovolcanoes

The sediment carried steadily within the water column flow of a stream is:

Suspended Load

Bed load

The material a stream carries along its bed by sliding, rolling, or bouncing (saltation)

What was Pangea?

a name for a former supercontinent that was made up of all present continents

A layered earth is important why?

because lighter continental rock allowed for the development of terrestrial life

High rainfall enhances what

chemical weathering

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

distribuataries

Alluvial sedimentary enviroments where the dominant deposits of clay and mud ?

floodplains

Rock Weathering can be:

form physical processes

Oceanic crust always subducts below continental crust because:

it is composed of denser mafic rocks

The French quarter in New Orleans is built on what?

natural levee

Where might you find a meandering stream

on a gently sloping plain of fine-grained sediment

Volcano domes are associated with ______ magma.

Felsic

Potholes in bedrock are formed by:

Abrasion by smaller rocks inside the pothole

Large, cone shaped deposits of sediment built up at the foot of a mountain in dry climates is called:

Alluvial fans

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

Basaltic

The type of lavas found at mid-ocean ridges and oceanic hot stops like Hawaii are:

Basaltic

The lava composition type would be more likely to flow a longer distance than other lavas?

Basaltic, because it has a lower viscosity than other lavas

Elongate, elevated sand ridges parallel to the coast of Western Louisiana are called:

Cheniers

Which of the following is most likely to be transported by suspended load? - Sand - Clay - Gravel

Clay

The surface of continental crust is at a higher elevation than oceanic crust because:

Continental crust has more felsic rock, which is less dense than the oceanic crust

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:

Delta

In general, Over the gradual opening of the Gulf of Mexico after Gondwanaland separated North America and the tectonic development of the Rocky Mountains, the deposition of sedimentary rocks in Louisiana progressed from:

Evaporite deposits,, to limestones, to sandstone and shale deposits

Gypsum (calcium sulfate) is an example of what?

Evaporitic mineral

What is true about the explosiveness of volcanic eruptions?

Explosiveness increases as the silica content of lava increases

If an igneous rock contains mostly quartz and feldspar, it's more likely to be:

Felsic

Fine-textured igneous rocks are typically formed where?

In the matle

The mineral olivine is an:

Isolated tetrahedral silicate

Calcite has perfect mineral cleavage which means:

It can break into flat surfaces in all three directions (rhombohedrons)

Diamond is the hardest mineral on Mohs scale of hardness because:

It has covalent bonding in a 3 dimensional framework

Salt from the deep Luann Formation can form salt diapirs that have been injected upward into overlying strata to form salt domes in Louisiana because:

It has low density and is Ductile under shallow crustal pressures It is squeezed upward by sediments deposited on top of it

Discovering the Benioff zone was important to the theory of plate tectonics because:

It used earthquake locations and depth trends to to define subduction zones

The most lethal phenomena to surrounding human communities of an erupting stratovolcano?

Lahars, a torrential mud flow of wet volcanic debris

The eolian deposit in the Baton Rouge area and is typical along the eastern side of the Mississippi River is called:

Loess

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

Mass movement

The maximum angle at which loose material on a slope will lie without sliding is called what?

The Angle of repose

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.

Coarse-textured igneous rocks have large crystals because:

They have cooled slowly

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

where isochrons are wider and farther apart