ch. 9 mountains

what is a geologic structure?

the arrangement of rocks, faults, and folds in eartch crust

what factors does elastic deformation depend on for rock stress?

temperature, pressure, and the type of rock

what factors does fractures depend on for rock stress?

the amount of stress, rock type, and temperature

what factors does plastic deformation depend on for rock stress?

temperature, pressure, and the amount of stress applied

what is an anticline fold?

upward fold

what is a syncline fold?

downward fold

what is a dome fold?

an uplifted area with older rocks in the center

what is a basin fold?

a downfold with younger rocks in the center

what does folding do?

it shortens the horizontal distance in rock

what is a strike-slip fault fold?

rocks slide past each other horizontally

what is a normal fault?

rocks move apart, creating space

what is a reverse fault?

rocks are pushed together

what is a thrust fault?

a type of reverse fault with a shallow dip

what is a slip?

the displacement of rocks along a fault

what is a fault zone?

an area of numerous fractures and faults

what is a mountain building?

an orogeny

where does mountain buildings occur?

at convergent plate boundaries, where tectonic plates collide

formation of island arcs, which crusts are involved?

they form when oceanic crust is subducted beneath another oceanic plate, causing volcanic islands

what happens to the sediment, what is a subduction complex?

sediment is scrapped off the subducting plate, forming a subduction complex

where is a trench located?

where the subduction occurs

where is a forearc basin located?

between the trench and the volcanic arc

what is a typical succession of events for a mountain-building at subduction zones?

1.) oceanic crust subducts beneath continental plate

2.) magma rises, forming volcanic arcs (ex: andes)

3.) crust thickening uplifts the mountains

which plates are involved in the formation of the Himalayas? (first subduction zone, then continent-continent collision, and extensive crustal thickening)

Indian plates and the Eurasian plate

when did the formation of the rocky mountains occur and what was special about it?

formed about 70 million years ago, during the Laramide Orogeny, with a unique form of crustal compression