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Dolomitization is a geological process by which the carbonate mineral dolomite is formed when magnesium ions replace calcium ions in another carbonate mineral, calcite. It is common for this mineral alteration into dolomite to take place due to evaporation of water in the sabkha area. [1] Dolomitization involves substantial amount of ...
Dolomite (also known as dolomite rock, dolostone or dolomitic rock) is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite, CaMg(CO 3) 2. It occurs widely, often in association with limestone and evaporites , though it is less abundant than limestone and rare in Cenozoic rock beds (beds less than about 66 ...
Dolomite is used as an ornamental stone, a concrete aggregate, and a source of magnesium oxide, as well as in the Pidgeon process for the production of magnesium. It is an important petroleum reservoir rock, and serves as the host rock for large strata-bound Mississippi Valley-Type (MVT) ore deposits of base metals such as lead , zinc , and ...
Precipitation of aragonite may be suppressed by the presence of naturally occurring organic phosphates in the water. Although ooids likely form through purely inorganic processes, the bulk of CaCO 3 precipitation in the oceans is the result of biological activity. [44] Much of this takes place on carbonate platforms.
Limestone is the most common carbonate rock [3] and is a sedimentary rock made of calcium carbonate with two main polymorphs: calcite and aragonite.While the chemical composition of these two minerals is the same, their physical properties differ significantly due to their different crystalline form.
Ore-hosting structures are most commonly zones of highly brecciated dolomite – these structures may be more or less vertical, crossing bedding at high angles, or they may be lensoid in shape extending in the same direction as bedding. A petrogenetic model to explain MVT deposits in general: The ore minerals fill cavities and fractures in ...
On a side note, this particular process (the replacement of aragonite and calcite with dolomite) is the most common form of recrystallization by replacement. Being similar to wet polymorphic transformations, recrystallization by replacement occurs on a variety of minerals, including chert, pyrite , hematite , apatite , anhydrite , and dolomite ...
This process results in roughly spherical concretions that grow with time. In the case of pervasive growth, cementation of the host sediments, by infilling of its pore space by precipitated minerals, occurs simultaneously throughout the volume of the area, which in time becomes a concretion. Concretions are often exposed at the surface by ...