dolomite formation

Dolomite: Mineral information, data and localities.

Althoff P L (1977) Structural refinements of dolomite and a magnesian calcite and implications for dolomite formation in the marine environment American Mineralogist 62 772-783: 1977: 0: 293: 0000904: Dolomite: Reeder R J, Wenk H R (1983) Structure refinements of some thermally disordered dolomites sample EU American Mineralogist 68 769-776 ...

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Dolomite and dolomitization model - a short review

Modern dolomite formation has been found to occur underconditions anaerobic in supersaturated saline lagoons in Brazil. In the high-Mg calcite, there is a 0-32 mol% of Mg substitution for Ca. In the protodolomite there is roughly 55-60 Mol% Cain the lattice with incomplete segregation

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Geolex — CopperRidge publications - USGS

The formation, which for present remains unnamed, was recognized at Knoxville; hence it is a part of typical Knox dolomite of Safford. In Tennessee and southwestern ia, where the Brierfield, Ketona, and Potosi formations have not been detected, the Knox rests on upper Cambrian formations, either the Nolichucky or the Conasauga shale.

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Learning Geology: Dolomite

As limestone and dolomite shares the same depositional environment as shallow marine, warm water where organism can accumulate which in turn when deposits form carbonate. So in formation of dolomite it is thought to be the alteration of carbonate by magnesium rich water, Magnesium in the water converts calcite into dolomite, This alteration is the chemical change in the …

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Influence of anhydritisation on the reservoir quality of ...

The permeability of the anhydrite-containing dolomite rocks composing Unit U.4 of the Butmah Formation is distributed predominantly between 0.1 mD and 10 −5 mD (9.87 × 10 −17 m 2 and 9.87 × 10 −21 m 2), with the highest occurrence (33.3% of the measurements) in the range 10 −3 mD – 10 −4 mD (9.87 × 10 −19 m 2 and 9.87 × 10 − ...

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Dolomite and dolomitization model- a short review ...

On the basis of the mode of formation, dolomites can broadly be divided into two groups: primary dolomite and secondary dolomite. 2 Primary dolomite precipitate directly from aqueous solution, mostly at or near room temperature (20-35 o C), with no CaCO 3 dissolution involved. 3 However, dolomite can also form as a secondary phase replacing the precursor mineral calcite …

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Dolomite Group: Mineral information, data and localities.

Althoff P L (1977) Structural refinements of dolomite and a magnesian calcite and implications for dolomite formation in the marine environment American Mineralogist 62 772-783: 1977: 0: 293: 0000904: Dolomite: Reeder R J, Wenk H R (1983) Structure refinements of some thermally disordered dolomites sample EU American Mineralogist 68 769-776 ...

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Three-Dimensional Geologic Model of the Arbuckle-Simpson ...

Formation is a sandy dolomite in the Hunton anticline area. These units are up to 125 meters and 40 meters thick, respectively, in the model area. Because little is known about the water-bearing properties of the Timbered Hills Group, and there is no identifiable confining layer that separates

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An Ecological Perspective on Dolomite Formation in Great ...

Alternatively, it has been suggested that removal of SO 4 2– has little effect on the potential for dolomite formation, but rather it is the accumulation of sulfide from SRBs that promotes formation of this mineral (Zhang et al., 2012a, 2013; Lu et al., 2018).

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Ordovician period of the Ozark Plateaus in Arkansas

Age: Early Ordovician Period Distribution: Northern Arkansas, Ozark Plateaus; southeastern Missouri Geology: The Powell Dolomite is generally a fine-grained, light-gray to greenish-gray, limy, argillaceous dolostone with thin beds of shale, sandstone, sandy dolostone, and occasionally chert. In the lower half of the formation a dark massive ledge with abundant drusy quartz has been located in ...

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Formation of Dolomite | Composition

Dolomite Formation. Dolomite formation took place millions of years ago. There are a variety of Dolomite Uses and the Dolomite Reserves are found in many countries around the world. The rocks in the earth's crust continuously undergo changes in their composition which leads to formation …

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dolomite | Formation, Structure, Properties, Uses, & Facts ...

Dolomite, type of limestone, the carbonate fraction of which is dominated by the mineral dolomite, calcium magnesium carbonate. Along with calcite and aragonite, dolomite makes up approximately 2 percent of the Earth's crust. Learn more about the structure, properties, and uses of dolomite in …

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Dolomite formation and biogeochemical cycles in the ...

The recently formulated microbial dolomite model provides the opportunity to view the geological history of dolomite formation from a new perspective. A biogeochemical approach to the 'dolomite problem' reveals a plausible connection between Phanerozoic geochemical cycles and dolomite formation.

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Geologic units in Big Horn county, Wyoming

Amsden Formation (South Wyoming) - Red and green shale and dolomite; at base is persistent red to brown sandstone. Alluvium and Colluvium (Pleistocene-Holocene) at surface, covers 6 % of this area Clay, silt, sand, and gravel in flood plains, fans, terraces, and slopes.

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Geological factors controlling the utility of refractory ...

@article{osti_5011824, title = {Geological factors controlling the utility of refractory dolomite: The Cambrian Ledger Formation dolomite, a case study}, author = {Furman, F C and Gregg, J M and Ablin, V C and Moore, R E}, abstractNote = {The Middle Cambrian Ledger Formation in eastern Pennsylvania is a high purity, single-stage-sintering dolomite.

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Modern dolomite formation caused by seasonal cycling of ...

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 …

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Geolex — LittleFalls publications

He stated that Hoyt limestone overlay Little Falls dolomite in Saratoga region and that the dolomite which overlay the Hoyt was a younger formation to which he applied name Skene. He classified Hoyt limestone as basal member of the Whitehall and Skene as upper member, the latter being a very late Upper Cambrian offlapping unit.

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KGS--Geological Log Analysis--Log Overlay Lithology

The Middle Ordovician Platteville Formation in Kansas is restricted to the north-east of the State and consists of dolomite, limestone, sandstone, and green shale. The basal part is a persistent dolomite that can be correlated across the region. The Platteville unconformably overlies the St. Peter Sandstone.

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Malmani Dolomites | South African Palaeocave Survey

To a large degree, our project is a field survey of the geological formation known as the Malmani Dolomite Subgroup, of the Chuniespoort Group of the Transvaal Supergroup. The Transvaal Supergroup is an extensive geological sedimentary rock sequence extending across much of the northern part of South Africa and into Botswana (Ericksson & Altermann, 1998).…

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New Insights into Formation of Mineral Dolomite | Geology ...

New Insights into Formation of Mineral Dolomite. A new study by a team of biologists and geochemists from GEOMAR-Helmholtz Centre for Ocean Research Kiel, Germany, has demonstrated that ...

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(PDF) Estimation of dolomite formation: Dolomite ...

Formation of dolomite can occur via two possible mechanisms: i) direct precipitation from solution to form primary dolomite, and ii) dolomitization process in which calcite undergoes dissolution ...

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Enthalpies of formation of dolomite and of magnesian …

and 0.25M MgClr. The enthalpy of formation of ordered dolomite from calcite and mag' nesite at 85"C is -5.74 + 0.25 kJ/mol, for a formula unit of dolomite containing I mol of cations. A synthetically disordered dolomite has an enthalpy of formation of + | .23 ! 0.32 kJlmol. At 85"C, four synthetic magnesian calcites with mole fraction, X, of MgCO,

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Dolomite: A sedimentary rock known as dolostone or ...

Formation of the Dolomites. The Dolomites are about 250 millions years old and are composed mainly of sedimentary rocks and limestone. Today, we can hardly imagine that once the mighty mountains were an enormous coral reef, formed in the primordial ocean called Tethys. (648) Accommodations. Culture.

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Dolomite Rock - Sedimentary Rocks

Dolomite or dolostone is a carbonate sedimentary rock containing more than 50% by weight of the mineral dolomite.Dolomite rock may contain calcite, but the content of calcite should not exceed 10% of the calcite-dolomite pair's content 3.. Dolomite in Northern Norway (Trollholmsund) which was once chalk, but the original material has been replaced with dolomite.

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Dolomite formation in the shallow seas of the Alpine ...

The Alpine Triassic units of Switzerland, Northern Italy and Western Austria offer an extensive geological archive, in which the enigmatic process of dolomite formation can be studied in a palaeoenvironmental context. Recent studies clearly demonstrate that large amounts of the Alpine Triassic dolomites are late diagenetic or hydrothermal.

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Dolomite - Microfluidic Systems and Components

Dolomite is pioneering the use of microfluidic devices for small-scale fluid control and analysis, enabling engineers and scientists to take full advantage of the following benefits: High Monodispersity. Microfluidic techniques offer extremely consistent size of droplets, particles …

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Dolomite - Properties, Composition, Distribution and Formation

Dolomite aquifers are important as aquifers and contribute to karst terrain formation because they can be dissolved by slightly acidic water. Composition of Dolomite Ferrous iron usually replaces some of the magnesium in dolomite, and a complete sequence between dolomite and ankerite [CaFe(CO 3 ) 2 ] …

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Chapter 4 Chemistry of Dolomite Formation - ScienceDirect

Secondly, the geologic history of a region must have permitted the chemical condition for the formation of dolomite mineral to persist long enough for sufficient quantity of the mineral dolomite to be formed in order to constitute a dolomite rock, or "dolostone". This chapter is only concerned with the chemical problem of dolomite formation.

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GIBBS ENERGY OF FORMATION OF DOLOMITE FROM …

° of –2147.82 62.20 kJ zmol-1 for dolomite is compared with other reported and calculated DG f ° values in table 2. discussion Of special interest in the formation of dolomite is the DG° rxn value for the reaction CaCO 3~s! 1 MgCO 3~s! 5 CaMg~CO 3! 2~s! (6) The value of DS° rxn for (6) is essentially zero, because the two-dimensional layered

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Proto-dolomite formation in microbial consortia dominated ...

Proto-dolomite precipitation can be conceived as a preceding step to the formation of ordered dolomite considering that the rate of cation ordering is a very slow process (Malone et al. 1996) accomplished by the re-crystallization of proto-dolomite to ordered dolomite via Ostwald ripening (Rodriguez-Blanco et al. 2015).

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Microbial community composition and dolomite formation in ...

The Khor Al-Adaid sabkha in Qatar is among the rare extreme environments on Earth where it is possible to study the formation of dolomite-a carbonate mineral whose origin remains unclear and has been hypothetically linked to microbial activity. By combining geochemical measurements with microbiologi …

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Dolomite - an overview | ScienceDirect Topics

Dolomite is a magnesium ore with the general formula MgCO 3 ·CaCO 3. The use of dolomite as a catalyst in biomass gasification has attracted much attention (Xu, Donald, Byambajav, & Ohtsuka, 2010). The chemical composition of dolomite varies from source to source, but it generally contains 30 wt.% CaO, 21 wt.% MgO, and 45 wt.% CO 2.

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The Birth of the Dolomites - Beautiful Mountains born out ...

Atoll formation and reef growth (after DARWIN 1842). Darwin proposed that volcanic islands with fringing reefs, islands with barrier reefs and atolls (i.e. ring-shaped reefs without a volcanic ...

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CONDITIONS FOR DOLOMITE FORMATION

CONDITIONS FOR DOLOMITE FORMATION. From the above comparisons of patterns among dolomite rhombs, carbonate particles, and lithified layers, and from the patterns of sedimentation, it is clear that although dolomite formation is somehow tied to high productivity, the important details remain unsolved when using only this field evidence.

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Estimation of dolomite formation: Dolomite precipitation ...

Increase in supersaturation, Mg +2 /Ca +2 ratio and CO-2 3 on the formation of dolomite at near room temperature are subtle except for temperature.This study suggests that microbial mediation is needed for appreciable amount of primary dolomite formation. On the other hand, reactive-transport models depicting dolomitization (temperature range ...

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History & formation of the Dolomites, UNESCO World Natural ...

Formation of the Dolomites. The Dolomites are about 250 millions years old and are composed mainly of sedimentary rocks and limestone. Today, we can hardly imagine that once the mighty mountains were an enormous coral reef, formed in the primordial ocean called Tethys. (648) Accommodations. Culture.

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