GEO 401 exam 2

Fossils are most common in which types of rocks?

sedimentary

The area on the surface of the Earth where P waves and S waves are not recorded by seismograms following an earthquake event are reffered to as______________.

shadow zones

What type of earthquakes would most likely occur in the middle of a divergent boundary?

shallow focus earthquakes caused by normal faulting

What type of earthquakes would happen on a lateral fault?

shallow focus earthquakes caused by strike-slip faulting

The Earth's magnetic field shields the surface of the Earth from ________________________.

solar winds

The Big Bang Theory indicates the universe originated as a single concentration of mass energy that rapidly expanded. Which of the following evidence supports this idea?

the Doppler redshift of the universe

In which region of the Earth is conduction the dominant heat transfer mechanism?

the crust

Which of the following Earth systems powers the Earth's magnetic field that can protect life on Earth's surface from harmful cosmic rays?

the geodynamo system in the Earth's core

Which of the following earth systems powers the Earth's magnetic field?

the geodynamo system in the Earth's core

The principle of superposition states that _______________.

undisturbed sedimentary layers get progressively younger from bottom to top

The only other planet in the solar system besides the Earth thought to be tectonically active is _____________.

venus

Which planet is surrounded by a hot atmosphere of carbon dioxide and clouds of sulfruic acid?

venus

The oldest continental crust contains rocks as old as ____________.

4 billion

A rock formed with 100 atoms of a radioactive parent element but contains only 25 radioactive parent atoms today. Let's assume that the rock did not contain any daughter isotopes to start with. If the half-life for the radioactive element is two billion years, how old is the rock?

4 billion years old

The Earth's upper mantle is mainly made of peridotite, an ultramafic igneous rock with lots of olivine crystals. Which type of magma can be produced when the upper mantle undergoes decompression melting of the upper mantle peridotite at mid-ocean ridges?

Basaltic

What types of lavas are erupted at mid-ocean ridges?

Basalts

what causes tides

gravity from the moon and the sun

Radioactive isotope dating is commonly used in geology to understand the ages of minerals and rocks. The parent radioactive isotope decays into the daughter isotope at a constant rate. The decay rate is measured by the amount of time required for half the remaining mineral to decay. This decay rate is called _____________.

half life

The giant outer planets are composed mostly of _______.

hydrogen and helium

Where are the oldest rocks in North America located?

in the canadian shield

The mineralogy of terrestrial planets evolves as a consequence of a range of physical, chemical, and biological processes. Based on the statement, the number of minerals in the Earth would ________ as the planet evolves through time.

increase

Seismic studies of the earth have shown that the platnet's interior is made of a few layers with distinct seismic signatures and chemical compositions. The major layers of the planet include (from innermost to the outermost layers) ____________.

inner core, outer core, mantle, crust

What principle is based on the continents being less dense than the underlying mantle?

isostasy

Earth's interior is made of a few distinct layers separated by discontinuous boundaries in seismic wave and geochemical studies. Which statement below is FALSE?

Earth's core is mostly made of iron-nickel alloy. The outer core is solid and the inner core is liquid.

Which of the following statements about radioactivity is FALSE?

Energy is consumed during radioactive decay

Point B, the location on the surface above the focus, is called the earthquake ___________.

Epicenter

Point A, where slip initiated during the earthquake is called the ________.

Focus

Which of the following correctly lists the three rock types in order of increasing P-wave velocity?

Granite -> gabbro -> peridotite

Which of the following metamorphic facies represents the highest temp?

Granulite

Isostasy is the balance (equilibrium) between buoyancy forces that push a continent up and down. Let's use water and ice as an example to understand isostasy. We know that ice flows on water bc it is less dense. Elevation of an ice cube is a function of the density difference and thickness of the ice layer. Which of the following statements is FALSE?

Ice is ~10% lighter in density than water. Thus, ~90% of the ice cube will submerge under water.

A number of geological principles such as Principle of Superpostion, Principle of Original Horizontality, and Principle of Faunal Succession have been used to understand geological records in rock formations. Based on these principles, which one of the following statements is TRUE?

In a sequence of undisturbed layered rock, the oldest rocks are on the bottom

Which region of the Earth consists primarily of solid iron?

Inner core

Magma generated in the Earth's interior rises because it is ______ than the surrounding rocks.

less dense

Which one of the following phenomena led to the conclusion that the outer core is liquid?

S wave shadow zone

Volcanic rocks derived from the Yellowstone hot spot get progressively older to the southwest. Based on this information in which direction is the North American plate moving?

Southwest

One particular group of bacteria, the cyanobacteria or "blue-green algae," have left a fossil record that extends far back into the Precambrian - the oldest cyanobacteria-like fossils are nearly 3.5 billion years old, among the oldest fossils currently known. ___________________ record the presence of microbial mats during the Archean.

Stromatolites

In which plate-tectonic environment do earthquakes occur at the greatest depths?

Subduction zones

Which of the following statements about the age of the Earth and Moon is TRUE?

The Earth and the Moon are approximately the same age

As the distance to an earthquake increases, _____________________.

The elapsed time before the S waves arrive increases

The effects of the collision of a large Mars-sized body with the Earth about 4.5 Ga is proposed to have caused _______________________.

all of the above - a magma ocean to form at the Earth's surface - an increase in the Eath's speed of rotation - the Earth's spin axis to tilt

How do rock particles move during the passage of an S wave through the rocl?

back and forth at right angles to the direction of the wave

Which of the following radioactive isotopes is the most useful for dating very young (<10,000 years old) wood and charcoal?

carbon-14

Unconformity is the surface between two layers that were laid down in a broken sequence. Which of the following statements about the unconformity are TRUE?

All of the Above - Angular unconformity is an unconformity in which younger sediments rest upon the eroded surface of tilted or folded older rocks - Disconformity is an unconformity between beds that are parallel - Nonconformity is an unconformity between stratified rocks above and unstratified igneous or metamorphic rocks below

Building Blocks of Life include:

All of the above - water - carbon, hydrogen, and oxygen -nutrients and energy

Melting occurs when a solid (rock) becomes a liquid (melt: magma). There are a number of pressure, temperature, and compostioinal conditions that can cause a rock to melt. Which one of the following conditions can cause a rock to melt in the Eath's deep interior?

All of the above -addition of volatiles such as water inti the rock - decompression (a decrease in pressure) - and increase in temperature

What volcano represents a major hazard to the cities of Seattle and Tacoma in Washington state?

Mt. Rainer

Which region in the earth is molten?

Outer core

A geothermometer is ____________.

a mineral assemblage that reveals the maximum temp attained by a rock

If an earthquake occurred in Seattle, Washington, how long would it take for the first seismic waves to arrive at a seismograph station is Miami, Florida, approximately 5000 kilometers away? Note that one can use the speed of the primary P wave to answer this question.

about 8 minutes