(PDF) Dolomite: Occurrence, Evolution and Economically …
Abstract. Dolomite is not a simple mineral; it can form as a primary precipitate, a diagenetic replacement, or as a. hydrothermal metamorphic phase, all that it requires is permeability, a ...
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Rock physical characteristics of deep dolomite under
After the precipitation of primary dolomite, the algal dolomite including stromatolite algal, laminar algal and bonded algae, formed the rock frame with dolomicrite crystals, and such microbial dolomite is characterized by the well-preserved original rock structure and the development of T framework pore and intergranular pores Fig. 2 (a).
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Dolomite | Formation, Structure, Properties, Uses,
dolomite, type of limestone, the carbonate fraction of which is dominated by the mineral dolomite, calcium magnesium carbonate [CaMg(CO 3) 2]. General considerations Along …
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Dolomite
Dolomite is quarried for building and ornamental stone, road stone, and the production of refractory brick. It is the principal ore of magnesium metal and the source of the magnesium used by the chemical industry. It is also used as flux and in preparing mag. salts. Brazil up to 35 cts. or more @ 100.00 per ct.
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Dolomite
Dolomite may be the sole or primary constituent of marble. Dolomarble from Fauske, Norway. Width of sample 14 cm. Dolostone is the most important rock type that is composed mostly of it. Dolostone was probably originally limestone which was altered by Mg-bearing water circulating in the rocks. Dolomite does not precipitate out of aqueous ...
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Dolomite and Dolomitization | SpringerLink
Dolomite is a trigonal–rhombohedral, ordered Ca, Mg carbonate mineral (CaMg (CO 3) 2) occurring primarily in sedimentary and metamorphic rocks. …
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An Early Holocene Primary Dolomite Layer of Abiotic Origin …
The "dolomite problem" is a long‐standing puzzle in sedimentology and mineralogy. Previous studies have shown that some dolostones are formed by microbes or in hydrothermal–burial environments. Here, we provide a different case in which an abiotic and Ca‐rich dolomite layer precipitated in Lake Sayram, Central Asia, during the early …
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(PDF) A New Model for Formation of Lacustrine Primary Dolomite …
Structural and isotopic characteristics of dolomites and relationships between temperature, salinity, and fluid density. (a) Cross‐plot of dolomite stoichiometry and cation ordering, showing ...
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A New Model for Formation of Lacustrine Primary Dolomite by Subaqueous
1 Introduction. Genetically, natural dolomites can be grouped into two families: (1) primary dolomites precipitated from solution, either as dolomitic sediment within/at the base of the water column or as dolomite cement within pre-existing voids, and (2) secondary dolomites formed through replacement (dolomitization) of calcite or …
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Microcrystalline dolomite in a middle Permian volcanic lake …
This study's findings deepen the understanding of the origin and processes of lacustrine primary dolomite formation and provide an alternative possibility for environmental interpretations of ...
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Origin and palaeoenvironmental indications of Eocene to …
Kinetic model for primary lacustrine dolomite formation. As mentioned above, the weathered Palaeozoic Mg-rich rocks, volcanic ash and contemporaneous evaporative saline lake water were likely the primary Mg 2+ sources for the formation of the Eocene to Oligocene lacustrine dolostones on the northern margin of the Tianshan …
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Proto-dolomite spherulites with heterogeneous interior …
Primary dolomite is believed to be formed through cyanobacterial calcification, yet the details and mechanisms of this process are not fully understood. In this study, a freshwater filamentous cyanobacterium, Leptolyngbya boryana, was cultured and domesticated in artificial freshwater and brackish solutions with various Mg/Ca ratios.
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Microcrystalline dolomite in a middle Permian volcanic …
Primary dolomite formation; non-evaporative environments 49 2022 International Association of Sedimentologists., Sedimentology, 70, 48–77 Warthmann et al., 2000; Hood et al., 2011). Recently, microcrystalline and disordered dolomite, which is a precursor of ancient well-ordered massive dolomite, has been found in modern and Neogene …
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Dolomite Rock
Dolomite may precipitate out of aqueous solutions ( sandstones with a dolomitic cement) and some dolomitic rocks are so-called primary dolomites. These were formed in …
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Dolomite
Dolomite is a common rock-forming mineral. It is the primary constituent of dolomite rock ( dolostone) and dolomarble. It is similar to the most common carbonate mineral calcite. These two share some similarities in …
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Nanoscale crystal fabric of primary Ediacaran dolomite
Primary dolomite precipitation from seawater in depositional environments has not yet been described. Here, we use synchrotron radiation to produce a nanoscale-resolution crystal orientation map of one exquisitely preserved ooid deposited at the onset of the Shuram carbon isotope excursion at ~574 Ma.
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Abiotically-formed, primary dolomite in the mid-Eocene …
Therefore, dolomite formation needs now to connect with the presence of smectite minerals in the precipitation medium. As revealed from petrographic characters of dolomite with its associated smectite (Fig. 4 a–h), the studied dolomite has been interpreted as a primary precipitate enclosing the previously-precipitated smectitic clay …
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"Microcrystalline Dolomite in a Middle Permian Volcanic …
Lacustrine dolomite nucleation commonly occurs in modern and Neogene evaporitic alkaline lakes. As a result, ancient lacustrine microcrystalline dolomite has been conventionally interpreted to be formed in evaporitic environments. This study, however, suggests a non-evaporitic origin of dolomite precipitated in a volcanic–hydrothermal …
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Co‐precipitation of primary dolomite and Mg‐rich clays in …
To test this hypothesis, the hydrology and mineralogy of Deep Springs Lake, a playa setting with primary dolomite precipitation has been explored. In this study, the central playa sites with the highest sedimentation rates were found to have dissolved silica concentrations close to saturation. Rietveld refinement showed that bulk mineral ...
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An Early Holocene Primary Dolomite Layer of Abiotic …
The distribution of primary dolomite in the Great Salt Lake is spatially heterogeneous, with only the carbonate mud in the South Arm and ridge‐site between desiccation cracks in the North Arm ...
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An Early Holocene Primary Dolomite Layer of Abiotic …
Here, we examined early Holocene sediments containing a 12-cm-thick layer that consists of abundant partially ordered dolomite (mean > 50 wt%) collected from Lake Sayram, Central Asia. By combining mineralogical and geochemical evidence, we con-firmed a primary and abiotic origin of this dolomite layer.
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Minerals | Free Full-Text | Can Primary Ferroan Dolomite …
Microbes can mediate the precipitation of primary dolomite under surface conditions. Meanwhile, primary dolomite mediated by microbes often contains more Fe2+ than standard dolomite in modern microbial culture experiments. Ferroan dolomite and ankerite have been regarded as secondary products. This paper reviews the process …
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Abiotically-formed, primary dolomite in the mid-Eocene …
Mineralogically, the mudrock facies is composed of clay minerals (40%), quartz (30%) and dolomite (30%) (Table 1). In thin section, dolomite occurs as. Discussion. In lacustrine/palustrine environments, several processes had been considered to interpret the primary/diagenetic dolomite.
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Dolomite and Dolomitization | SpringerLink
Ancient dolomite formed through both primary precipitation and replacement (dolomitization) of CaCO 3, presumably by Mg-rich fluids. In modern systems, primary dolomite is constrained to hypersaline environments, such as lagoons (e.g., Vasconcelos and McKenzie 1997 ) and sabkha environments (e.g., Wright and Wacey 2005 ), and …
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An Early Holocene Primary Dolomite Layer of Abiotic …
We report a case of a primary abiotic lacustrine dolomite layer formed during the early Holocene in Lake Sayram, Central Asia. …
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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 …
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Dolomite and dolomitization: Implications for reservoir
The dolomite cements, generally found in carbonates and clastics, are precipitated directly from pore fluids during diagenesis (Tucker and Wright, 1990; Chen et al., 2019). The dolomite cement can also be primary dolomite cement or the replacement of calcite cement (Adams and Mackenzie, 1998).
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(PDF) Estimation of dolomite formation: Dolomite …
dissolution and dolomite precipitation, comes out as approximately 0.03 scaled length unit x 0.27 cm/unit = 0.008 cm and the. dolomitization profile (b) yield a velocity of 1.74 x 10 -1 cm/yr ...
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Genetic types and distinguished characteristics of dolomite and …
With an example of the primary dolomite pre- cipitated in microbial mats on the Sabkha coast and microbial dolomite in the Fourth Member of Dengying Formation in the Sichuan Basin, petrological and geochemical features of such dolomite are elaborated. In microbial mats on the modern coast of Abu Dhabi (99.60% microbes are Desulfovibrio ...
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A route for the direct crystallization of dolomite
There are two main mechanisms by which dolomite can form in the natural environment: (1) "directly from solution" or primary dolomite, and (2) dolomites that …
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