RE: questionturr,I am not a geologist by any stretch of the imagination,so my response to your question as to the
relationship between hydrocarbon deposits and salt deposits should to be taken "with a grain of
salt"...how's that for a pun.
As you know, sedimentary rocks form from the accumulation and deposition of sediment over a long
period of geologic time, which eventually harden .It is these sedimentary rocks in which hydrocarbons
are normally found.
Sedimentary rocks can also be formed by the precipitation of minerals (such as salt) out of water.In
other words, minerals that have been dissolved in water as it moved downstream toward the ocean can
later become undissolved or precipitated out of the water to form solids again(salt).
Over time, this accumulation and compression of salt may form a salt dome, a form of structural trap
which seals off or retards the migration of oil and gas accumulation, and concentrates it in a limited
space.As you might have guessed, geologists and geophysicists look for these potential hydrocarbon
traps in recommending drilling locations in their search for hydrocarbon deposits.
In short, salt is a form of sedimentary rock which often forms into a dome like
structure(anticline-shaped) , serving the function of an impermeable sealing rock to trap hydrocarbons
(Source-An Introduction to the Petroeum Industry by Phonse Fagan...Geophysicist, Dept of Mines and
Energy, Government of Nfld. and Labrador).
Hope this helps answer your question.
Len