sentences:  Sulfide minerals such as galena, sphalerite, marcasite and pyrite thus form.Commonly MVT deposits form by the combination of hydrocarbon pyrolysis liberating zinc-lead ions and sulfur to form an acidic solution which dissolves the host carbonate formation and replaces it with massive sulfide accumulations.This may also take the morphology of fault-hosted stockworks, massive tabular replacements and so forth.