Front | Back |
In Wegener's evidence for continental drift, continents were proposed to fit together, such as the east coast of South America with the ____________
|
Lower west coast of Africa
|
What word means unsorted material deposited directly by glacial ice and showing no stratification?
|
Till
|
Glacial _____________ are scratches or gouges cut into bedrock by glacial movement.
|
Striations
|
Evidence that glaciers once covered an area might include _________.
|
Till and striations
|
Abundant swamps led to the formation of coal during the Late Paleozoic in which of the following places?
|
North America
|
Wegener's idea of continental drift was rejected by American geologists because _____________.
|
He could not conceive of a valid mechanism that would cause continents to shift positions.
|
If a geologist discovered coal in a modern-day cold, snowy location, he or she could conclude that ___________.
|
The area was once covered with swamps and/or jungles .
|
If a geologist discovered striations (scratches) on bedrock surfaces and small hills compared of poorly sorted sediment, what could he or he conclude about the area?
|
The glaciers had once covered the area.
|
Limestone reefs and salt deposits are important rocks in the the reconstruction of Earth's history because they _________________.
|
Can be used to infer the ancient climate of Earth; they are deposited in environments that are restricted to warm climates.
|
The apparent tendency of the north (or south) magnetic pole to vary in position over time is termed ________
|
Polar wander
|
What does an ordinary compass mean?
|
Magnetic north
|
In the geologic past, the polarity of Earth's magnetic field is _______.
|
Known to have experienced numerous reversals, as shown by remnant magnetization of iron-rich minerals in rocks
|
Seafloor spreading _______________.
|
Creates new oceanic crust
|
Seafloor spreading occurs at ____________ boundaries.
|
Divergent
|
The discovery of seafloor spreading finally provided a mechanism for ______________.
|
Continental drift
|