Intrusive magma is cooler because it is well insulated by the surrounding rock.
Intrusive magma flows onto the Earth's surface and cools very slowly, allowing many small mineral grains to grow.
The extrusive magma cools quickly so the mineral grains do not have time to grow.
The extrusive magma, because it is deep below the surface, cools very slowly, producing very small mineral grains.
The pressures that different minerals are formed in metamorphic rocks
Which minerals are recrystallized in a sedimentary rock
The temperatures at which different minerals crystallize out of a melt
All of the above
None of the above
Granite; intrusive rock that formed from cooling of relatively high silica magma.
Rhyolite; extrusive rock that formed from cooling of relatively low silica magma.
Diorite; intrusive rock that formed from the cooling of relatively intermediate silica magma.
Basalt; extrusive rock that formed from cooling of relatively low silica lava.
Temperature of the environment – lower T = slower magma cooling.
The presence or absence of volatiles (gases) – more gases = slower magma cooling.
Temperature of the environment – higher T = slower magma cooling.
Pressure of the environment – lower P = slower magma cooling.
The changing of a rock from one set of minerals to another
The compaction of metamorphic rocks
The melting of sedimentary rocks
The cooling of magma
Both c and d are correct.
Cools so fast that mineral grains cannot crystallize and grow
Cools so slowly that only one mineral is formed
Is a rhyolitic type
Cools at an extremely high temperature
The rock heats up and expands at lower pressures, causing it to liquefy.
Temperatures remain high as lowered pressures decrease melting temperatures.
The lowered pressures cause rapid heat loss accompanied by melting.
None of the above.
Magmas are more viscous than solid rocks in the crust and upper mantle.
Most magmas are richer in silica than most crustal and upper mantle rocks.
Magmas are mainly liquid and contain dissolved fluids and gases such as water; most are less dense than the adjacent solid rock.
All of the above.
The crater of a large, extinct cinder cone filled with water; 5 million years ago
Caldera collapse followed major ash and pyroclastic-flow eruptions; 6,000 years ago
Landslides and volcanic mudflows dammed the Mazama River; 500 years ago
A powerful explosion blew away the top of a stratovolcano: 10 million years ago
A thick stack of welded-tuff layers
A field of large stratovolcanoes
A flood basalt plateau
A caldera filled with rhyolitic lava flows
The eruption added large amounts of carbon dioxide to the atmosphere.
The eruptive cloud destroyed parts of the Earth's protective ozone layer.
Radioactive atoms blown into the atmosphere glowed red as they decayed.
Sulfur dioxide and other erupted gases formed aerosols in the stratosphere.
Frost wedging, exfoliation, biological activity, dissolution
Exfoliation, thermal expansion, biological activity, hydrolysis
Exfoliation, frost wedging, expansion, hydrolysis
Frost wedging, unloading expansion, thermal expansion, biological activity
Soil-forming processes occur from the bottom-up. This causes vertical variations in soil composition, texture, structure, and color.
Soil-forming processes occur from top-down. This causes vertical variations in soil composition, texture, structure, and color.
Soil-forming processes occur in single layers at a time. This causes each layer to appear differently in composition, texture, structure, and color.
Soil-forming processes occur laterally in the same layer, so different vertical profiles allows geologists to determine that variation from place to place.
Less humus is produced in the tropical rainforest because the B horizon is so poorly developed.
Less humus is produced in the cool, temperate forest but the rate of decay and oxidation is slower than in a tropical rainforest.
More humus is produced in the tropical rainforest, but it is quickly washed away by the heavy rains.
In a tropical rainforest, the forest-floor litter is often burned during the dry season.
Corn; rows trending straight down the slope, frequent cultivation.
Apples; land between the trees is planted in grass and not cultivated.
Winter wheat; after the harvest, the field is plowed and left idle until next fall.
Beans; rows are spaced wider than on a level field.
North-facing slopes receive more sunlight in the summer; snow melts faster and more soil moisture is available for the trees.
South-facing slopes receive more moisture and sunlight; rock weathering is slower.
North-facing slopes receive about the same amount of precipitation as south-facing slopes; less moisture evaporates from north-facing slopes.
South-facing slopes receive less moisture, yet rock weathering is faster.
Reduces the grain sizes of rock particles
Allows for faster rates of chemical weathering
Is important in the formation of talus slopes
Involves a change in the mineral composition of the weathered material
Usually wind unless there have been very heavy rainstorms in the area
Usually water unless it is very dry in the region
Both are approximately equal in terms of power globally.
Crystal structure of each grain
Temperature at which it was formed
Environment of deposition
Method of turning into a metamorphic rock