Geo 101 Chpt 2

Based on evidence from fossils, glacial deposits, and the fit of the continents, Wegener proposed continental drift that suggested all of the continents were once.

• aligned north to south along the prime meridian

• aligned east to west along the equator

• combined to form a supercontinent (he termed Rodinia)

• combined to form a supercontinent (he termed Pangaea)

Tags

NGSS.MS-ESS2-3

Wegner’s idea of continental drift was rejected by American geologists because.

• his English was too poor to be understood by them

• he could not conceive of a valid mechanism that would cause continents to shift positions

• he had relatively little evidence supporting the existence of a supercontinent

• the apparent fit of continental coastlines is blurred when the margins are defined by the edges of continental shelves rather than at sea level.

Tags

NGSS.HS-ESS1-5

Currently, most geologists.

• continue to reject continental drift

• agree that continental drift occurs, but they still do not understand why it occurs

• agree that continental drift occurs; the mechanisms that drive drift are at work in the ocean basins and upper mantle and were unknown in Wegener’s time

• agree that continental drift occurs; the mechanisms that drive drift are at work in the lower mantle and outer core and were unknown in Wegener’s time

Tags

NGSS.MS-ESS2-3

The apparent polar-wander paths for continents indicate actual position of the paleopole.

• True

• False

Tags

NGSS.HS-ESS1-5

Sea-floor spreading is driven by volcanic activity.

• in the middle of abyssal plains

• along mid-ocean ridges

• at the edges of continental shelves

• along fracture zones

Tags

NGSS.MS-ESS2-2

Regions of the sea floor with positive magnetic anomalies were formed during times when Earth’s magnetic field.

• was exceptionally strong

• was exceptionally weak

• had normal polarity

• had reversed polarity

Regions of the sea floor with negative magnetic anomalies were formed during times when Earth’s magnetic field.

• was exceptionally strong

• was exceptionally weak

• had normal polarity

• had reversed polarity

Tags

NGSS.HS-ESS1-5

Marine magnetic anomaly belts are widest when and where.

• continents are joined to form supercontinents

• sea-floor spreading rates are relatively rapid

• sea-floor spreading rates are relatively slow

Tags

NGSS.HS-ESS1-5

The age of oceanic crust with increasing distance from a mid-ocean ridge.

• increases

• decreases

Tags

NGSS.MS-ESS2-1

Wegener’s evidence for a united Pangaea was so compelling that virtually all geologists agreed with the idea of continental drift during his lifetime.

• True

• False

Tags

NGSS.HS-ESS1-5