Name: Colbert
Status: Student
Grade: 9-12
Location: N/A
Country: Israel
Date: March 2009
Question:
Will dolomite or sandstone hold up better to weathering in
an arid desert environment?
Replies:
It fully depends upon the sandstone.
Dolomite usually weathers chemically and that requires water. Chemical erosion
in a desert is limited. Both rocks will, however be subject to mechanical weathering.
This includes: abrasion from blowing dust and sand as well as thermal weathering -
the heating and cooling of rock that happens when rocks heat up in the sun cool and
then cool to much lower temperatures in the desert night. The rock expands and
shrinks at the surface and the surface eventually flakes off.
Sandstone's resistance to physical onslaught depends upon what is holding the grains
of the rock together. You can find sandstones that have so little holding the grains
together that you can crush it with your bare hands. That rock will not do well
against physical weathering. If the grains are held together (cemented) by limestone
or, better yet, silica (quartz), they could be very resistant to weathering in a desert
environment.
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