On the origin of the Neoproterozoic Peresopolis graphite deposit, Paraguay Belt, Brazil

Manoel, Talitta Nunes; Leite, Jayme Alfredo Dexheimer

doi:10.1016/j.jsames.2018.03.007

Cited by 5 publications

(3 citation statements)

References 48 publications

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“…Hence, our Re-Os dating of organic material provides a robust assessment for the age of the unit. We note that the organic carbon isotopic data for the Peresopolis black slate is homogeneous, with δ 13 C values between -28 and -29 ‰ (Manoel and Leite, 2018), which are typical for Neoproterozoic organic matter.…”

Section: Samplingmentioning

confidence: 73%

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A pre-Sturtian depositional age of the lower Paraguay Belt, Western Brazil, and its relationship to western Gondwana magmatism

et al. 2021

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The Neoproterozoic Paraguay Belt in mid-eastern Mato Grosso, western Brazil, records the geological evolution of the margins of western Gondwana. The lack of absolute geochronology for the Paraguay Belt has hampered both regional and global stratigraphic correlations. Here we determine the depositional age for the Peresopolis black slate that belongs to the base of the Cuiabá Group in the Paraguay Belt using Re-Os geochronometry. We obtain a narrow Re-Os age interval of 784 ± 8 Ma and a juvenile initial 187 Os/ 188 Os composition (Osi) of 0.15 ± 0.03. These data indicate that the Peresopolis black slate is Tonian in age and was deposited in a basin strongly influenced by the weathering of juvenile material, and potentially linked to the early rifting of Rodinia on western Gondwana. These slates record a time interval that is poorly represented in Brazil and with few counterparts in other Neoproterozoic basins globally. As such, our work is a foundation for future geochemical correlations and paleoenvironmental reconstructions of this critical transition of Earth history in Brazil and elsewhere.

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Section: Samplingmentioning

confidence: 73%

“…Raman spectroscopy on organic matter has shown that the unit was metamorphosed to lowgreenschist facies conditions, with peak metamorphic temperatures not exceeding ca. 300°C (Manoel and Leite, 2018). The mineral assemblage includes quartz, muscovite and sulfides like pyrite and sphalerite.…”

Section: The Peresopolis Slatementioning

confidence: 99%

A pre-Sturtian depositional age of the lower Paraguay Belt, Western Brazil, and its relationship to western Gondwana magmatism

et al. 2021

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“…Carbonaceous graphite deposits are genetically classified as syngenetic or epigenetic (Weis, Friedman, & Gleason, 1981). The carbon in syngenetic deposits is of organic origin and can be completely transformed into graphite through the action of metamorphic processes (Manoel & Leite, 2018).…”

Section: Ore Genesismentioning

confidence: 99%

Metamorphism, geochemistry, and carbon source on sedimentary‐metamorphic graphite deposits in eastern Shandong, China

et al. 2019

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Eastern Shandong is one of the most economically important regions for oreproducing sedimentary-metamorphic graphite deposits in China. The Liugezhuang and Daliangzikou graphite deposits in the Pingdu-Laixi Graphite Belt are typical examples. The ores in the Liugezhuang deposit and Daliangzikou deposit are typically gneiss/granulite type and biotite granulite type, respectively. Graphite occurs as stratabound layers of slender flakes associated with biotite, clinopyroxene, and plagioclase and as slender flakes and disseminated grains associated with biotite and filling tiny fractures in mineral grains. The mineral associations indicate that the ore rocks can be classified into four metamorphic facies: (a) amphibolite granulite facies, Cpx (Hy) + Opx (Di) + Pl ± Hbl ± Qz; (b) amphibolite facies, Hbl + Pl + Cpx (Opm) + Ep + Bt + Ms + Qz ± Chl ± Mic; (c) high-grade greenshist facies, Hbl + Pl + Ep + Bt + Chl + Qz ± Cpx; and (d) low-grade greenshist facies, Ep + Chl + Pl + Bt + Ms + Chl + Qz + Rt. Study of the variation in graphite crystalsand fixed carbon with increasing metamorphic grade suggests that more than one metamorphism process (graphitization) occurred during ore formation. Geochemical analysis indicates that the primary condition under which the Liugezhuang and Daliangzikou graphite deposits formed was a marine facies sedimentary environment of which the material source was terrestrial weathering detritus and compounds and also a participation of terrestrial material in the graphite deposits. Trace element data suggest that the sedimentary condition was from a reducing condition in the Liugezhuang graphite deposit to a weaker reducing condition in the Daliangzikou graphite deposit, whereas samples from a Jingshan Group stratum show multiple oxidation-reduction conditions but dominantly oxidation. Carbon isotope analysis indicates that the carbon source of the Liugezhuang graphite deposit was organic, whereas that of the Daliangzikou graphite deposit was mainly organic carbon but with some inorganic participation.

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Metric, kilometric and large-scale coherence of metamorphic conditions from graphitic phyllite in the Upper Lesser Himalaya of Nepal: Contribution to the estimation of carbon stored during Himalayan orogeny

et al. 2023

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On the origin of the Neoproterozoic Peresopolis graphite deposit, Paraguay Belt, Brazil

Cited by 5 publications

References 48 publications

A pre-Sturtian depositional age of the lower Paraguay Belt, Western Brazil, and its relationship to western Gondwana magmatism

A pre-Sturtian depositional age of the lower Paraguay Belt, Western Brazil, and its relationship to western Gondwana magmatism

Metamorphism, geochemistry, and carbon source on sedimentary‐metamorphic graphite deposits in eastern Shandong, China

Metric, kilometric and large-scale coherence of metamorphic conditions from graphitic phyllite in the Upper Lesser Himalaya of Nepal: Contribution to the estimation of carbon stored during Himalayan orogeny

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