Carbonate-hosted lead-zinc ore deposits 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. Porous limestones may form disseminated ores, however most MVT deposits are massive sulfides with knife-like margins between carbonate and sulfide mineralogies. Ore minerals in carbonate replacement deposits are typically lead sulfide, galena, and zinc sulfide sphalerite. Weathered equivalents form anglesite, cerussite, smithsonite, hydrozincite and secondary galena and sphalerite
Ore shoot Ore shoot In mining and geology, an ore shoot is a long seam of mineral or metal bearing rock that can be profitable to extract. The term may have originated in the 17th and 18th centuries when various theories existed on the origins of ore deposits, including some that suggested they grew like trees. Tabular or sheet-like deposits of metalliferous ores often contain areas of enhanced metal content that are larger in one dimension than another. A structure may contain multiple ore shoots. A "vein," "lode" or other mineral-bearing structure could be thick, steeply inclined within the host rock, persisting