The landscapes of
Death Valley are abundant with examples of faulting. The picture
below is of the Furnace Creek Badlands in Death
Valley. The mountains are marked with what is
called normal faulting by extension. Extension occurs when the stress
being applied to the rock is in opposite directions and pulls apart
the rock. The process of extension leads to a form and process called stretching. Eventually the rock can break
under this stress to create normal faults by extension. The many
triangular facets along the sides of the mountains and the wine glass valleys forming along the base of the mountains are forms
in which the process of faulting by extension manifests itself.
Photo Credit: http://library.byways.org/
This particular
mountain below possesses numerous examples of diastrophism
all along its surface. The thick white layer running along the side
shows folding. Its folding comes in the form of anticlines (convex
bends upward) and synclines (concave bends in a depression). This was
accomplished through stresses being applied against each other from
opposite sides. This type of process is called compression and it can
lead to the rock deforming in the manner of folding.
Towards the right
side of the mountain, the white layer of rock breaks cleanly only to
continue above unconnected. This would be an example of strike-slip
faulting left lateral. More towards the center of the mountain there
appears to be a strike-slip fault in the right lateral
direction. Strike-slip faults are created by side by side lateral
stress (from the perspective of looking along the layer) in opposite directions; this process (called shearing) warps
and deforms the rock horizontally (from the perspective of looking along the layer), which can lead to the strike-slip faults shown above.
I think your explanation on the formation of faults in the Furnace Creek Badlands in Death valley was perfect. It gave me a better grasp of faulting by the process of extension. The wine glass valley example you gave for faulting was a spot on example of what the process of extension forms. I will be visiting Death Valley this summer for my job, so your blog was very informitive. I will try to visit the Furnace Creek badlands and get a better look.
ReplyDeleteGreat job! I may have a chance to visit the Death Valley during spring break or on late May. But I haven't do any preparing work now. Your explaination of Death Valley gives me a deeper understanding of it, and it will help me a lot for the preparation work. in your blog, you mention the normal faulting by extension, which is really interesting I think. I'll take some photoes about it. Thanks
ReplyDelete--Long Chen