How dolomite [CaMg(CO3)2] forms is still underdetermined, despite over a century of efforts. Challenges to synthesizing dolomite at low temperatures have hindered our understanding of sedimentary dolomite …

Here, the authors contradict the view that modern dolomite formation is rare and suggest instead that dolomite accounts for ~40–60% of the global oceanic Mg output in the last 20 Ma.

To decode the enigma of ancient dolomite, we examined a modern dolomite forming environment, and found that a cyclic shift in microbial community …

The Dolomite occupies approximately 2% of Earth's crust. Dolomite formation occurs under anaerobic conditions. The mineral occurs in the form of dolomite marble, dolomite carbonatite, and dolomite-rich veins. Magnesium in Dolomite can be substituted by other cations like ferrous iron, lead, barium, zinc, and manganese.

The proposed reactions (Table 3) apply to the formation of dolomite only when a gel or suspension is present during the intermediate reaction. The gel or suspension serves to retard the reaction so that a better crystallinity is observed in the products, and under some conditions it abets the formation of dolomite at the expense of calcium ...

Dolomite is a common rock-forming mineral. It is a calcium magnesium carbonate with a chemical composition of CaMg (CO 3) 2. It is the primary component of the sedimentary rock known as dolostone and the …

Dolomite forms in hydrothermal veins or as a pore-filling mineral in carbonate rocks, and more rarely as an accessory component in igneous pegmatites or altered mafic igneous rocks. By far though, most dolomite …

1. Introduction. Dolomite formation and dolomitization in the sedimentary realm are subjects of long-standing interest and study (Shukla and Baker, 1988, Purser et al., 1994, Burns et al., 2000, Deelman, 2011).It is one of the most important sedimentary minerals: in the subsurface dolomite forms the reservoir rock for a large proportion of …

The formation of the mineral dolomite is still puzzling scientists. Researchers have now shown that bacteria can facilitate the formation of dolomite. The study has been published online in the ...

Dolomite is a carbonate mineral frequently found in sedimentary rocks from Proterozoic to Holocene.In the Iberian Peninsula, dolomites appear in a wide number of geological formations and they can be considered as representative of dolomites crystallised in most (post)sedimentary environments on Earth.In this paper, we present a first …

Formation: Dolomite forms in various geological settings, typically through a process called dolomitization. This process involves the alteration of limestone by …

The crystal structure of dolomite is similar to calcite with Mg ions substituting for Ca in every other layer. To accommodate this substitution, due to differences in bond lengths between Ca–CO 3 and Mg–CO 3 (238 pm versus 208 pm, respectively), CO 3 in the Mg layer is uniformly rotated about the threefold axis relative to calcite (Reeder and …

Dolomite formation in the quaternary has also been linked to changes in water and redox chemistry that led to elevated cell mortality and organic matter turnover 29. Thus, it seems that the ...

Since dolomite formation is thermodynamically favoured in solutions of (a) low Ca²⁺/Mg²⁺ ratios, (b) low Ca²⁺/CO3²⁻ (or Ca²⁺/HCO3⁻) ratios, and (c) high temperatures, the ...

Extrapolation of kinetic datasets obtained from dolomite formation through Ca-Mg carbonate intermediates and estimation of the time needed for the ordering of the dolomite crystal lattice (cf. Eq ...

The crystal structure of dolomite is similar to calcite with Mg ions substituting for Ca in every other layer. To accommodate this substitution, due to differences in bond …

Most rocks that are rich in dolomite were originally deposited as calcium carbonate muds that were postdepositionally altered by magnesium-rich …

The chemical and/or hydrological conditions of dolomite formation are still poorly understood, and often more than one mode of genesis appears feasible (see Machel, 2005). Part of this problem lies in the fact that it is difficult to crystallize (ordered) dolomite in the laboratory under ambient conditions and, in addition, current dolomite ...

Dolomite (CaMg(CO3)2) plays a key role in the global carbon cycle. Yet, the chemical mechanisms that catalyze its formation remain an enigma. Here, using batch reactor experiments, we …

Dolomite [CaMg(CO 3) 2] formation under Earth surface conditions is considered largely inhibited, yet protodolomite (with a composition similar to dolomite but lacking cation ordering), and in some cases also dolomite, was documented in modern shallow marine and lacustrine, evaporative environments.Authigenic carbonate mud from …

The Dolomia Principale formation produced some of the most imposing mountains in the Dolomites, including the Three Peaks of Lavaredo, the Cristallo and the Tofana. 170 million years ago: the domain of the giant …

It has been demonstrated that VHMC formation always precedes the formation of ordered dolomite in high-temperature laboratory synthesis experiments (Gregg et al., 2015). While common in older rocks, dolomite and protodolomite are rare in modern marine sediments despite waters being supersaturated with respect to these …

In sedimentary dolostones, dolomite is most often associated with calcite, aragonite, gypsum, anhydrite, chert, and halite. Vein deposits of dolomite occur with quartz and other common vein minerals, such as calcite, magnesite, fluorite, siderite, and sphalerite, or with metallic ore minerals such as galena, pyrite and chalcopyrite.

The Dohat Faishakh sabkha in Qatar is one of the rare modern environments where it is possible to study the formation of dolomite, a mineral whose origin has been long debated. In previous studies, dolomite formation in this area was considered to be the result of a penecontemporaneous replacement of aragonite, occurring in the presence of …

In an ideal structure of dolomite, alternating layers of Mg 2+, Ca 2+ are interspersed with CO 3 2− groups oriented normal to the c-axis (Fig. 1), with a Mg/Ca molar ratio of 1 (stoichiometry) and an ordered arrangement.The larger radius Ca 2+ occupy A sites and the smaller radius Mg 2+ occupy B sites. The standard unit cell parameters of …

Geographically extended to AL. Uses Knox dolomite in table of geologic formations of AL. Part of Ordovician. The Knox dolomite is prominent formation in Appalachian Valley. It is a massive calcareous rock that generally occupies the central portion of valley. Overlies Cambrian Coosa shale; underlies Ordovician Pelham …

Dolomite originates in the same sedimentary environments as limestone - warm, shallow, marine environments where calcium carbonate mud accumulates in the form of shell …

In this case, the formation of dolomite changed seawater chemistry, the opposite of the argument of Hardie (1996). Using micro-inclusion studies of halites of varying ages Zimmermann (2000) has concluded that the evolving chemistry of the Phanerozoic ocean is more indicative of changing volumes of dolomite that it is of changes in the …

Dolostone is a rock that consist of >75 percent dolomite. Dolostones are alsocalled dolomites, especially in the literature prior to about 1990, but the term dolomites should be used only for different types of dolomite. Two types of dolomite formation are common, that is, dolomitization, which is the replacement of CaCO 3 by CaMg (CO 3) 2, and ...

'sabkha dolomite') dolomite formation is the Peru continental margin, where dolomite was first recovered by deep-sea dredging during the Nazca Plate Project (Kulm et al., 1981, 1984) and during the Ocean Drilling Programme (ODP) Leg 112 (Suess et al., 1988). Different dolomite assem-blages with variable d13C values ranging from )14