geo 2 Flashcards
The Columbia Plateau in Washington and Oregon is ________.
A large igneous province formed by extensive basaltic lava flows.
What is the largest known volcano in the Solar System?
Olympus Mons on Mars.
How is the recent (geologically) volcanic activity in Yellowstone National Park related to plate tectonics?
It is caused by a mantle hotspot, independent of plate boundaries.
Which type of basaltic lava flow has its surface covered with sharp-edged, angular blocks and rubble?
A’a lava.
Which type of basaltic lava flow has a fairly smooth, unfragmented, ropy surface?
Pahoehoe lava.
The finely divided, red, brown, and yellow soil-coloring minerals originate by what process?
Chemical weathering, particularly oxidation.
What processes are involved in mechanical weathering?
Frost wedging, exfoliation, thermal expansion, biological activity, and abrasion.
Which terms best describe those processes that move weathered rock materials and soils downslope?
Mass wasting or mass movement.
Describe the characteristic processes involved in soil erosion.
Detachment, transport, and deposition by wind, water, or gravity
What happens when water fills a crack in a rock and undergoes cycles of freezing and melting?
The crack expands due to frost wedging, eventually breaking the rock apart
In which area are pedocal soils most likely to be found?
: In dry, arid, and semi-arid climates.
In correct order from the center outward, Earth includes which units?
Inner core, outer core, mantle, crust.
________ rocks always originate at the surface of the solid Earth.
A) Metamorphic B) Secondary C) Sedimentary D) Igneous
C) Sedimentary.
The ________ proposes that the bodies of our solar system formed at essentially the same time from a rotating cloud of gases and dust.
Nebular hypothesis.
The ________ forms the relatively cool, brittle plates of plate tectonics.
Lithosphere.
Are Mount St. Helens and the other Cascade volcanoes young or old, active or inactive, and what type of margin produces them?
They are young, active, and formed at a convergent plate boundary (subduction zone).
What are the major pieces of evidence supporting the theory of plate tectonics?
Fossil distribution, seafloor spreading, paleomagnetism, earthquake patterns, and GPS measurements.
The temperature below which a magnetic material can retain a permanent magnetization is called the ________.
Curie temperature.
Where is the top of the asthenosphere closest to Earth’s surface?
At mid-ocean ridges.
Which diseases are linked directly to prolonged inhalation of asbestos dust?
Lung cancer, asbestosis, and mesothelioma.
The strong tendency of certain minerals to break along smooth, parallel planes is known as ________.
Cleavage.
Which group of minerals are the most abundant in the Earth’s crust?
Silicates.
Which igneous rocks exhibit aphanitic texture?
Basalt, andesite, rhyolite.
Changing the composition of magma by incorporating surrounding host rock is known as ________.
Assimilation.
A ________ texture would be most unlikely to occur in an extrusive igneous rock
Pegmatitic texture.
What factors influence the melting temperatures and viscosity of magmas?
Temperature, silica content, and water content.
________ destroyed the city of St. Pierre, Martinique in 1902.
A pyroclastic flow from Mount Pelée.
A ________ is an intrusive, igneous rock body that is tabular and concordant.
Sill.
Under similar warm, moist climatic conditions, why would basalt and gabbro generally have higher chemical weathering rates than rhyolite and granite?
Because basalt and gabbro contain more mafic minerals, which weather more quickly than felsic minerals.
Lateritic soils form under what climatic conditions?
Warm and humid tropical climates.
Compared to the age of Earth accepted as correct today, how did 17th and 18th century proponents of catastrophism envision the Earth’s age?
They believed Earth was only a few thousand years old.
________ is often paraphrased as “the present is the key to the past.”
Uniformitarianism.
Why is so much basaltic magma erupted along mid-ocean ridges?
Due to decompression melting as the lithosphere pulls apart.
What are the lightest or least massive of the basic atomic particles?
Electrons.
________ is composed mainly of ferromagnesian minerals.
Peridotite.
Which of the following statements concerning humus is not true?
A) consists of decaying and partly decayed leaves and other plant materials
B) is readily leached from the B horizon in weakly acidic, soil solutions
C) is typically found above the B soil horizon
D) is less abundant in wet, tropical, forested areas than in temperate, forested areas
B) is readily leached from the B horizon in weakly acidic, soil solutions.
________ was the highly influential, ancient Greek philosopher noted for his writings and teachings on natural philosophy and on the workings of Earth.
Aristotle.
Early results of the Deep Sea Drilling Project clearly justified the conclusion that ________.
The ocean floor is younger near mid-ocean ridges and older further away, supporting seafloor spreading.
Which of the following will react readily with acids such as hydrochloric?
A) talc B) calcite C) quartz D) diamond
B) Calcite.
Which igneous rock or magma has the lowest silica (SiO₂) content?
Ultramafic rocks, such as peridotite.
Which statement about the May, 1980, eruption of Mount St. Helens is false?
A) The most powerful explosive event was preceded by a massive landslide.
B) Mudflows accompanied the major eruptive events.
C) During the eruptive period, the mountain peak was substantially built up by new lava flows and pyroclastic debris.
D) Plumes of ash rose high into the atmosphere during the major eruptive events.
C) During the eruptive period, the mountain peak was substantially built up by new lava flows and pyroclastic debris.
Which term describes a soil formed by weathering of the underlying bedrock?
Residual soil.
What is the difference between magma and basalt?
Magma is molten rock beneath Earth’s surface, while basalt is a solidified extrusive igneous rock formed from magma.
