help.
2007-10-16 15:25:10 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Earth Sciences & Geology
a fault, like the San Andreas Fault
2007-10-16 15:33:06 · answer #1 · answered by D4rkArrow 2 · 0⤊ 0⤋
A rift valley - formed by violent subterranean forces that tear apart the earth's crust. These forces cause chunks of the crust to sink between parallel fault lines and force up molten rock in volcanic eruptions. Evidence of this process is called rifting. They are also known as a graben. They are usually narrow and long and have a relatively flat floor. The sides drop away steeply in steps or terraces.
Examples - African Rift System, Russia's Baikal Rift Valley and Germany's Rhine Rift Valley.
2007-10-16 15:52:29 · answer #2 · answered by Roisin F 2 · 1⤊ 0⤋
Sounds like you're talking about Rift Valleys. They are formed when a divergent plate boundary transects continental crust.
2007-10-16 15:34:43 · answer #3 · answered by skeptik 7 · 2⤊ 0⤋
Well, it's not CANYON. Canyons are caused by the sudden rush of water down one of things you are talking about it. :)
2007-10-16 15:34:56 · answer #4 · answered by Anonymous · 0⤊ 0⤋
rilles - atleast that's what they are called on the moon ^_^
2007-10-16 15:31:48 · answer #5 · answered by Anonymous · 0⤊ 1⤋