Chapter 8 Flashcards
It’s the name for the supercontinent proposed by Alfred Wegener
Pangaea
This piece of evidence for continental drift emanates from the coastlines of continents
Jigsaw-puzzle fit
This piece of evidence for continental drift involves dead things with hard parts in sedimentary rock layers
The correlation of similar fossils in rock layers across the continents
The name of the organism whose fossilized remains have been found in rock layers across the Atlantic Ocean coastlines
The Mesosaurus
These have been found to be similar in age and type across the “puzzle pieces”
rock layers
The remnants of these led scientists to believe that the continents were once joined along the Atlantic coastlines during times of similar climates
glaciers
The belief that ancient igneous rocks containing iron cooled in such a way that the iron-containing minerals lined up pointing like a compass needle toward the Earth’s magnetic poles.
Paleomagnetism
Once magnetite cools below this point (about 585°C), crystals form and become magnetic again in the direction of the magnetic field lines that exist at the time of the cooling.
Curie point
The alignment of the magnetite in some rock layers appears to be exactly opposite of what it is today; this change in polarity is called a __________.
Magnetic Reversal
The alternative view of Plate Tectonics proposed that this caused runaway subduction
A crack in the ocean floor caused by a sudden trigger
The magma that wells up into the divergent boundaries/rift zones does so for this reason
Hotter fluids like magma are less dense than colder, solid ocean rocks
Once the magma reached the ocean water (in the alternative view), it’s what happened
The massive amount of magma vaporized water, producing supersonic jets of water
It’s the Scripture that is consistent with #3
Genesis 7:11-12, because it “rained for 40 days and 40 nights”
A map of the seafloor of the world’s oceans produced evidence of this Atlantic undersea landform, which is the longest on Earth
What is the Mid-Atlantic Ridge?
These landforms were discovered in the Pacific Ocean during the seafloor mapping project; areas of subduction result in the formation of these
What are deep-ocean trenches?
The lithosphere is broken into seven of these
Plates
The names of these seven lithospheric divisions
African Plate Antarctic Plate Australian-Indian Plate Eurasian Plate North American Plate Pacific Plate South American Plate?
The lithosphere is thickest here and thinnest there
the lithosphere is thickest at the mountains (continental crust) and thinnest in the oceans (oceanic crust)?
The area just below the lithosphere that exhibits “plastic” behavior, allowing the plates to move above it
the asthenosphere
The concept that the processes that have shaped Earth in the geologic past are essentially the same as those operating today
Uniformitarianism
The concept that Earth was shaped by catastrophic events of a short-term nature
Catastrophism
List the major factors given as evidence for paleomagnetism
Polar wandering
Alignment of magnetic minerals in igneous rock layers
Magnetic reversals
________ occurs at convergent plate boundaries;
________ occurs at divergent plate boundaries
subduction and seafloor spreading, respectively
According to the theory of plate tectonics, these two factors must have been present for the Hawaiian-Island Chain to form
continental drift and a stationary hot spot within the mantle
The driving forces of plate motion
Convection within the mantle
Subduction of crust material and upwelling at oceanic ridges
Unequal heat distribution within the mantle
This type of plate boundary involves plates moving away from each other; this is where they are generally found
divergent boundaries; the Atlantic Ocean
This type of plate boundary involves plates moving toward each other; this is where they are generally found
convergent boundaries; the Pacific and Indian Oceans
Plate boundaries where two plates grind past each other without the production or destruction of lithospheric material; these boundaries are sometimes called conservative margins
transform fault boundaries
It was the goal of the Deep Sea Drilling project in the Atlantic Ocean
To show that the youngest part of the seafloor is along the Mid-Atlantic Ridge (the age of the rocks increased with increasing distance from the ridge, supporting the seafloor spreading hypothesis)
The diverging of plate boundaries results in the upward movement of mantle material, forming __________.
New crust (lithospheric material)
Along divergent plate boundaries, the sea floor is elevated, forming an oceanic ridge. The oceanic ridge system is the longest _____________.
longest topographic feature on Earth, at 43,000 miles (70,000 km) in length
The process of crust divergence within a continent
Continental rifting
The process of crust divergence on the ocean floor
Seafloor spreading
The reason new crust material is created along divergent boundaries
The main reason for the upwelling found along the ridges is the relatively warm temperature of the new crust material. Hotter materials occupy more volume and are less dense than cooler materials, so they rise to the top. As they cool, they sink and are eventually displaced with more crust material
Areas of convergence where oceans meet continents and produce mountain ranges through volcanic activity; Mountains formed in this way are called _______________.
Oceanic-Continental convergence; continental volcanic arcs
Areas of convergence within oceans that also produces volcanic activity leading to the formation of mountains that eventually emerge above the surface of the oceans. Mountains formed in this way are called ________________.
Oceanic-Oceanic convergence; volcanic island arcs
Areas of convergence between two continental plates that produces uplift of one plate and subduction of the other.
Continental-Continental convergence?
The process that occurs at convergent boundaries that makes them prone to earthquake and tsunami production
subduction
It’s how each of the following mountain structures were formed:
Himalayas
Andes
Aleutian, Mariana, Tonga Islands
The structures were formed by:
continental-continental convergence
oceanic-continental convergence
oceanic-oceanic convergence?
The Answers in Genesis article put forward two pieces of evidence that dispute the evidence put forward in the textbook’s perspective of plate tectonics (listed below). It’s the differences in the perspectives:
magnetometer readings that were used to support the ages of the rocks in the seafloor
The values of magnetism in the actual rocks are very erratic and not like the smooth zebra-like pattern (in the textbook’s version) moving evenly away from the mid-ocean ridges that was obtained from averaged magnetometer readings above the rocks
The Answers in Genesis article put forward two pieces of evidence that dispute the evidence put forward in the textbook’s perspective of plate tectonics (listed below). It’s the differences in the perspectives: sediments in deep-ocean trenches
Slow-and-gradual subduction would produce sediments that are compressed and deformed, but soft, flat-lying sediments devoid of compressional structures are what is actually found in the Peru-Chile and East Aleutian Trenches?
The catastrophic plate tectonics model requires a trigger to cause a crack in the ocean floor around the supercontinent. Once the crack is formed, it’s what happens next
The floor adjacent to the cracks starts penetrating vertically into the upper mantle, followed by a series of increasing deformations in the mantle that eventually led to the catastrophic runaway of the oceanic slabs
It’s where the energy for the answer to #1 comes from
The gravitational potential energy of the cold, dense rock
what causes the large-scale convection within the mantle that follows #1 and #2
Once the crust is subducted rapidly, the hot mantle rock upwells to complete the flow cycle, causing large-scale convection
’s whether the laws of physics support these assertions
Yes; mantle rocks weaken under stress by factors of a billion or more, providing the necessary energy
It’s what happens once the runaway subduction of oceanic crust begins
The hot mantle rock wells up to the seafloor rift zones across the globe. The cooling process vaporizes huge volumes of ocean water
It’s what happens to the ocean water when the hot mantle rock reaches it
It produces a linear curtain of supersonic steam jets along the 43,500 mile seafloor rift zones stretching around the globe
It’s what happens to all this water after
This water is catapulted high above the earth and then falls back to the surface as intense global rain
It’s what could have caused this higher sea level
A newly-formed lower-density (hot) ocean floor
It’s the result of such a rise in sea level
The ocean waters would thus have swept up onto and over the continental land surfaces, carrying vast quantities of sediments and marine organisms with them to form the thick, fossiliferous sedimentary rock layers we now find blanketing large portions of today’s continents. This laterally extensive layer-cake sequence of sedimentary rocks is magnificently exposed, for example, in the Grand Canyon region of the southwestern U.S.?
The runaway subduction proposed in the catastrophic model of plate tectonics would have cooled the mantle temperature (due to cooler materials being forced into the mantle), resulting in convection and heat loss from the outer core. It’s what could have resulted from this process
rapid reversals in the Earth’s magnetic field
