Magmatic graphite in dolomite carbonatite at Pogranichnoe, North Transbaikalia, Russia

Doroshkevich, A. G.; Wall, Frances; Рипп, Г. С.

doi:10.1007/s00410-006-0150-z

Cited by 43 publications

(14 citation statements)

References 36 publications

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“…The presence of LREE -and Sr -enriched apatite, baddeleyite, zirconolite, perovskite and phlogopite together with mantle -like carbon isotope signatures and LREE -rich nature of carbonates (calcite) are definitely supportive of carbonatite -type of melts . Graphite was recently reported from dolomite carbonatite at Pogranichnoe, Russia, which also has mantle carbon isotope signatures (Doroshkevich et al, 2007). We believe that C responsible for the formation of graphite in these rocks was in the form of CO 2 in the source melts and the crystallization of graphite occurred by C saturation under reduced environment and continued until it reach higher oxidation state.…”

Section: Discussionmentioning

confidence: 68%

Origin of graphite in glimmerite and spinellite in Achankovil Shear Zone, southern India

Rajesh

Arai

Satish-Kumar

2009

Journal of Mineralogical and Petrological Sciences

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We report occurrence and origin of graphite in glimmerite and spinellite from an unusual ultramafic complex in Achankovil Shear Zone (ACSZ) in southern India. Raman analyses of primary graphite flakes in close association with spinel and phlogopite confirm the highly crystalline nature. The carbon isotope composition ranges from -7‰ to -9.8‰ typical of mantle -derived graphite. A genetic model is proposed in which carbon was derived from a reduced juvenile mantle source linked to the genesis of volatile rich ultramafic rocks in ACSZ.

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Section: Discussionmentioning

confidence: 68%

Origin of graphite in glimmerite and spinellite in Achankovil Shear Zone, southern India

Rajesh

Arai

Satish-Kumar

2009

Journal of Mineralogical and Petrological Sciences

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“…However, several other morphologies have also been reported. These include spherulites Kvasnitsa and Yatsenko 1991;Kvasnitsa et al 1998;Doroshkevich et al 2007; ), fibrous types (Jaszczak 1995;Jaszczak et al 2007), and cones (Jaszczak et al 2003(Jaszczak et al , 2007. Morphological characteristics can help in understanding the process and environment of crystal growth as well as provide insights into the precursors of carbonaceous materials (Double and Hellawell 1995;Rakovan and Jaszczak 2002;Mostefaoui et al 2005;Jaszczak et al 2007; Barrenechea et al 2009).…”

Section: Graphitization and Isotopic Exchange Between Calcite And Gramentioning

confidence: 95%

Relationship between structure, morphology, and carbon isotopic composition of graphite in marbles: Implications for calcite-graphite carbon isotope thermometry

Satish-Kumar¹,

Jaszczak²,

Hamamatsu³

et al. 2011

American Mineralogist

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Carbon isotope exchange between calcite and graphite is a useful and reliable geothermometer for medium-to high-grade marbles. However, in rare instances, such as at Naxos, Greece, apparent disequilibrium carbon isotope fractionation between calcite and graphite has been previously reported. In this study, new results are presented on the morphological features, X-ray diffraction studies, Raman spectroscopic studies, and carbon isotope studies of graphite. Three morphologically distinct graphite types are identified. The first type is fine grained with distinct polygonal crystal aggregates having smooth pinacoid faces. The second type consists of large botryoidal aggregates with typical crystal overgrowth features, and the third type is "normal" large platy crystals associated with phlogopite. Graphite morphological features using an FE-SEM suggests that the botryoidal aggregates are composed of complexly intergrown and stacked graphite layers, comprised of cone-helix structures. Different types of graphite display distinct Lc (002) and DG values as well as a sharp first-order Raman peak at ∼1580 cm -1 with disordered bands. The presence of Raman disordered bands in fine-grained well-crystallized graphite is attributed to edge effects. Carbon isotope analysis of graphite reveals that marble with fine-grained well-crystallized graphite show a consistent isotope fractionation with the calcite, which perfectly match temperature estimates based on the mineral isograds. In contrast, coarse botryoidal graphite gives heterogeneous carbon isotope values (about a few per mill) and show anomalous carbon isotope fractionation between the calcite and graphite. The graphite associated with phlogopite also shows variations in the carbon isotope values. Combining morphologic, crystallographic, and carbon isotopic data we conclude that the variations in carbon isotopic composition were caused by the overgrowth of graphite on the preexisting grain and that morphological observations and structural characterizations of graphite crystals is a key for predicting isotopic equilibration during metamorphism.

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“…Sometimes, intergrowths of several spherulites were observed. Spherulitic CM morphology has not been previously described in any rocks of the Keivy Terrane, although it is known in various geological objects [46][47][48][49]. Sillimanite schists contain four CM morphologies: In addition to CM-1 and CM-2, nest (CM-3) and vein (CM-4) varieties.…”

Section: Morphology Of Carbonaceous Mattermentioning

confidence: 99%

Carbon Sources and the Graphitization of Carbonaceous Matter in Precambrian Rocks of the Keivy Terrane (Kola Peninsula, Russia)

et al. 2019

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The Precambrian rocks of the Keivy Terrane reveal five types of carbonaceous matter (CM): Fine-grained, flaky, nest, vein, and spherulitic. These types differ in their distribution character, carbon isotope composition, and graphitization temperatures calculated by the Raman spectra of carbonaceous material (RSCM) geothermometry. Supracrustal rocks of the Keivy Terrane contain extremely isotopically light (δ13CPDB = –43 ± 3‰) carbon. Presumably, its source was a methane–aqueous fluid. According to temperature calculations, this carbon matter and the host strata underwent at least two stages of metamorphism in the west of the Keivy Terrane and one stage in the east. The CM isotope signatures of several samples of kyanite schists (δ13CPDB = –33 ± 5‰) are close to those of oils and oil source rocks, and they indicate an additional carbon reservoir. Thus, in the Keivy territory, an oil-and-gas bearing basin has existed. Heavy carbon (δ13CPDB = −8 ± 3‰) precipitated from an aqueous CO2-rich fluid is derived from either the lower crust or the mantle. This fluid probably migrated from the Keivy alkaline granites into the surrounding rocks previously enriched with “methanogenic” carbon.

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Magmatic graphite in dolomite carbonatite at Pogranichnoe, North Transbaikalia, Russia

Cited by 43 publications

References 36 publications

Origin of graphite in glimmerite and spinellite in Achankovil Shear Zone, southern India

Origin of graphite in glimmerite and spinellite in Achankovil Shear Zone, southern India

Relationship between structure, morphology, and carbon isotopic composition of graphite in marbles: Implications for calcite-graphite carbon isotope thermometry

Carbon Sources and the Graphitization of Carbonaceous Matter in Precambrian Rocks of the Keivy Terrane (Kola Peninsula, Russia)

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