Structures of Mineral Deposits
Sedimentary Deposits
Mineral deposits formed as a consequence of sedimentary processes occur
generally as lenses or beds which parallel enclosing sedimentary rocks,
and may extend for thousands of feet or tens of miles, but are rarely
more than a hundred feet thick. These deposits occur in sedimentary
basins, along ancient slopes and stream channels, and in ancient
lagoons. However, similar deposits may occur as a consequence of
replacement of reactive beds of limestone or dolomite - usually at the
base, or as impregnation of a permeable strata unit, giving the
impression of initial deposition.
Structural Deformation
Structural deformation may alter the form and attitude of some of these
deposits. For example, salt domes along the coast of the Gulf of Mexico
result from the squeezing of the salt from flat- lying beds, intruding
upward along zones of weakness. Many limestone beds have been severely
tilted and even overturned.
Metamorphic Processes
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