Answer 1:
This is an interesting question. Salt (Halit or
NaCl/CaCl) is a mineral and behaves like ice or
any other mineral with respect to its density.
Continental crustal rocks e.g. have lower
densities than oceanic crustal rocks. There for
the oceanic crust is subducted at active
continental margins. Salt is accumulated in the
oceans and sedimented, joined with other
sediments. After millions of years they are
compacted. When the sea level falls, or the sea
floor is uplifted, the sediments start to
erode. The salt now seeks its way up (salt
domes) and extrudes on the surface forming
plugs.
One distinguishes different types of plugs: small
and big forms (1-10 miles), passive and
active.
The
active form is what you are looking for. They have
an uplift between 2 to 4 inches per year, some
authors recorded 1 to 2 mm/a. They have a great
amount of evaporates outcropping on the surface
and have a salt glacier, that now flows out of the
plug downhill (density!) and accumulates in a dell
e.g.
The arid climate is important. In a
humid climate the salt would go into solution
immediately. Also important is the tectonic
activity of an area.
Through the Persian Golf
runs a fault system, that was formed due to the
continent-continent collision of the Arabic and
the Asiatic plate. It formed a complex of
anticlines (concave folds) on the south
coast of
Iran. The plugs are associated with the
anticlines.
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