Geology 1103 test 1

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:

100x stronger

Pangea is a name for:

A former supercontinent that was made up of all present continents

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

A= Pressure, B=Temperature, C= Depth

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

Basalt

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

Compressional

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

Contact metamorphism

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

Continental Drift

The tectonic boundaries with the deepest focus earthquakes would be:

Convergent boundaries

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

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

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

Elastic Rebound Theory / stress

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

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

Felsic

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

Felsic/Intrusive

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

Focus

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

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 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

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

Pahoehoe

At convergent plate tectonic margins:

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

At divergent plate boundaries:

Plates move apart and new lithosphere is created

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

Rhyolite, because it has a higher silica content than other lavas

Volcanoes with felsic composition lavas usually form which of the following landforms:

Stratovolcanoes

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

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

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

The half-life of a radioactive isotope is:

The time required for one-half of the original number of radioactive parent atoms to decay into stable daughter atoms

Coarse-textured igneous rocks have large crystals because:

They cooled slowly

What are the most deadly phenomena of earthquakes from epicenters in or near an ocean:

Tsunami waves

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

During metamorphism, a rock undergoes mineralogical and textural changes:

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

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

The seafloor was youngest in the middle and composed of volcanic rock 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

Seismic P waves are also known as:

Compression waves

A blueschist rock indicates______ metamorphism typical of ________.

High pressure, low temperature / subduction zones

In a sequence of sedimentary strata, an unconformity represents:

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

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

Brittle

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

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

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

Basalt

Oceanic crust always subducts below continental crust because it is:

Composed of denser rocks