question i got wrong in quiz Flashcards
(29 cards)
The distinction between the crust and the mantle is primarily on the basis of a difference in
composition
The primary difference between lithospheric and asthenospheric mantle that gives rise to numerous different patterns of physical behavior is ________.
temperature: the lithosphere is cooler than the asthenosphere
At transform plate boundaries, ________.
earthquakes are common but volcanoes are absent
Which layer of Earth does NOT contain silicates?
outer core
The interior of Earth consists almost entirely of ________ rock.
solid
In general, if a body of igneous (source) rock is subjected to partial melting, the magma that is produced is expected to be ________.
more felsic than the source rock
Volcanic arcs form along ________ boundaries.
convergent
The textural term for a basaltic lava flow that has a smooth, ropy appearance is ________.
pahoehoe
Thick accumulations of sediments and fossils in the deep ocean tend to be ________-sized due to the low amounts of energy.
clay
A sill is a(n) ________.
tabular intrusion that lies parallel to surrounding layers of sedimentary rock
What traits would a clastic sedimentary rock have if it had traveled far from its source and was carried in a current with uniform energy? What environment would this be?
A clastic rock that had traveled far from its source and carried in a uniform energy current would have well-rounded, well-sorted sediment that would contain very stable minerals such as quartz. This environment would be a beach
Throughout Earth’s history North America has hosted shallow inland seas. Why is the interior of North America dry today?
The North American continental crust has thickened significantly since the last inland sea.
The formation of a hotspot is thought to be associated with ________.
mantle plumes
If horizontal sedimentary strata overlie tilted strata (and no fault is present), the surface between the horizontal and tilted strata must be a(n) ________.
angular unconformity
A tilted sequence of sedimentary rocks violates which principle?
original horizontality
Radiometric dates applied to sedimentary rocks produce ages that ________.
are too old (predate sedimentary deposition)
Metamorphism includes a solid-state change in a rock due to heat, pressure, and/or hydrothermal fluids. Explain what is meant by solid-state change.
A solid-state change takes place when the rock is solid, in other words the rock has not been melted or weathered into a solution. All changes in size, shape, or composition of minerals is done while the rock remains solid.
Which of the following processes CANNOT occur in the formation of metamorphic rock?
the realignment of minerals so that they develop a preferred orientation
the segregation of minerals into layers of different compositions
the solid-state rearrangement of atoms or ions to create a new assemblage of minerals
complete remelting of the rock, followed by solidification to form a new rock
complete remelting of the rock, followed by solidification to form a new rock
Did the dinosaurs walk on Pangea?
Yes, some of them did, because Pangea did not break up until the Jurassic Period.
Which of the following would NOT be considered evidence for an orogeny?
folded strata
thrust faulting
disconformities
sedimentary basins
disconformities
The majority of the rocks that are formed at the surface of Earth are ________ rocks.
sedimentary
How were mammals able to take over as the dominant class of organisms on Earth?
Mammals were able to take over after the dinosaurs were wiped out. The small rodent-like mammals from the Mesozoic were able to adapt and fill the ecological niches left by the dinosaurs.
Marble and quartzite are nonfoliated rocks because ________.
both are dominated by minerals that produce equant grains
As compared with metamorphism, diagenesis ________.
takes place at lower temperatures and pressures
