Famous Erosional Landforms (L17) Flashcards
How is Tower Karst Topography formed?
near-surface dissolution of limestone produces steep-walled stream valleys and surface depressions called sinkholes
uplift enhances the deep downcutting of streams and lowering of water table. Continued downcutting of stream, deep dissolution, and cavern collapse leads to the formation of deep valleys
What is a Mesa?
an isolated, table-shaped, high plateau with a flat top and steep sides
A butte?
like a mesa, but is smaller in its dimensions and often pinnacle-shaped
How was the Colorado Plateau created?
believed that the Pacific Plate subducted at an unusally shallow angle, and that part of the subducted slab detached and disrupted the regular mantle flow
this disturbance led to a regional upwelling of magma from the asthenosphere
this area that was uplifted by the warm lithsophere is the Colorado Plateau
What is the main factor that created the roadrunner-coyote scenery?
stream erosion by downcutting streams
what further enhances the erosion in the areas where the roadrunner scenery is located?
the lack of vegetation
How was the Grand Canyon created?
resulted from the rapid and deep downcutting of streams and specifically, mass wasting
how are badland topography created?
results from the sporadic, but rapid erosion of weakly cemented sedimentary strata by water runoff and due to the scarcity of vegetation
where does the term “badlands” come from?
comes from a term in french which means “bad lands to travel through”
What is the Ship Rock?
a volcanic neck that stands higher than surrounding terrain b/c the intrusive volcanic material of the neck weathers less readily than the surrounding rocks
What are 2 things that are unusual about the Devil’s Tower?
- was first though to be associated with volcanism, but the texture of the rock is aphanitic to porphyritic suggesting that it was extruded rather than intruded (like a volcanic neck)
- it also has hexagonal joints
Which landscape was in an early Spielberg movie?
The Devil’s Tower
What is the Half Dome?
a natural monument that was originally a full dome, but a sheer cliff at the top of the dome was produced by the collapse of rock along a deep, near vertical joint (the collapsed material later transported away by the glacier)
What is the Sugarloaf Mountain?
an exfoliation dome, but in this case, the rock is Gneiss (a metamorphic rock)
How did Sugarloaf come to be?
sugarloaf is one of many features and that these features are simply erosion-resistant pods of rock that once belonged to a much more extensive metamorphic body
