Matches in SemOpenAlex for { <https://semopenalex.org/work/W4313503771> ?p ?o ?g. }
- W4313503771 endingPage "104182" @default.
- W4313503771 startingPage "104182" @default.
- W4313503771 abstract "Large, globally documented negative δ13C excursions that occur across the Permian-Triassic transition are thought to represent the isotopic fingerprint of considerable releases of isotopically light carbon into the atmosphere, with the largest of these excursions (as much as −22.2‰) measured in bulk organic matter in coals and carbonaceous shales from Antarctica. Previous studies have attributed the carbon isotopic excursion (CIE) at the Permian–Triassic boundary to the release of CH4 from organic-rich rocks intruded by dikes and sills associated with the Siberian Traps flood basalts (Russia) and Longwood-Bluff (New Zealand) intrusions. However, any assessment of paleoatmospheric conditions based on this or other δ13Corg excursions must consider the multiple controls on isotopic composition, including maceral content and post-depositional diagenetic and maturation processes. Permian-age coal seams and associated sediments in Antarctica were extensively altered after burial by localized high heat flow and, in some cases, by contact metamorphism associated with Jurassic dikes and sills. Levels of organic maturation reach anthracite, meta-anthracite, and even graphite; such intense thermal alteration had the potential to change the carbon isotopic composition of the bulk organic matter (δ13Corg). To evaluate the Permian–Triassic isotopic excursion in Antarctica, it is important to understand the inherent variability in δ13Corg in Permian-age coal and organic-rich sedimentary rocks prior to the CIE; thus, 128 samples representing pre-boundary coals and shales were selected from the United States Polar Rock Repository for analysis. Petrographic (maceral analysis and vitrinite reflectance), geochemical (C, H, N), and carbon isotopic analyses were performed. Based on the presence of coarse-grained circular and fine-grained lenticular mosaic in the anisotropic cokes found in samples in close proximity to intrusions, the rank of the samples prior to intrusion is estimated to have been medium volatile bituminous (∼1.2% Rmax). These highly altered coals and cokes can have random vitrinite reflectances (Rr) exceeding 6%. Subsequent to intrusion, alteration beyond the contact aureoles continued due to high heat flow, producing high rank coals with Rr > 2%. Values of δ13Corg range between −26.5 and –21.1‰ (5.4‰ difference). Significant relationships (at the 1 and 5% levels) exist between δ13Corg and the level of organic maturity, organic carbon (Corg) content (i.e., size of the carbon reservoir), and total inertinite content, suggesting variability due to these factors should be considered when assessing isotopic excursions and interpretation of Permian-Triassic atmospheric conditions. These findings highlight the importance of incorporating organic petrography into δ13Corg studies." @default.
- W4313503771 created "2023-01-06" @default.
- W4313503771 creator A5020342410 @default.
- W4313503771 creator A5033409101 @default.
- W4313503771 creator A5042521580 @default.
- W4313503771 date "2023-02-01" @default.
- W4313503771 modified "2023-10-11" @default.
- W4313503771 title "Carbon isotopic composition and organic petrography of thermally metamorphosed Antarctic coal: Implications for evaluation of δ13Corg excursions in paleo-atmospheric reconstruction" @default.
- W4313503771 cites W1505358646 @default.
- W4313503771 cites W1770113505 @default.
- W4313503771 cites W1964545290 @default.
- W4313503771 cites W1967439516 @default.
- W4313503771 cites W1968729709 @default.
- W4313503771 cites W1968846036 @default.
- W4313503771 cites W1969473919 @default.
- W4313503771 cites W1969830802 @default.
- W4313503771 cites W1973305248 @default.
- W4313503771 cites W1974751831 @default.
- W4313503771 cites W1974975954 @default.
- W4313503771 cites W1975860668 @default.
- W4313503771 cites W1976490418 @default.
- W4313503771 cites W1976721572 @default.
- W4313503771 cites W1980139183 @default.
- W4313503771 cites W1981325155 @default.
- W4313503771 cites W1983769075 @default.
- W4313503771 cites W1985676578 @default.
- W4313503771 cites W1985860443 @default.
- W4313503771 cites W1986916739 @default.
- W4313503771 cites W1988772771 @default.
- W4313503771 cites W1989670782 @default.
- W4313503771 cites W1990316074 @default.
- W4313503771 cites W1993570908 @default.
- W4313503771 cites W1995530895 @default.
- W4313503771 cites W1997395811 @default.
- W4313503771 cites W1998331282 @default.
- W4313503771 cites W1998804687 @default.
- W4313503771 cites W1998947146 @default.
- W4313503771 cites W1999064728 @default.
- W4313503771 cites W1999863855 @default.
- W4313503771 cites W2001244091 @default.
- W4313503771 cites W2003394352 @default.
- W4313503771 cites W2004144637 @default.
- W4313503771 cites W2004305320 @default.
- W4313503771 cites W2005720896 @default.
- W4313503771 cites W2008155461 @default.
- W4313503771 cites W2008469722 @default.
- W4313503771 cites W2008910856 @default.
- W4313503771 cites W2009107120 @default.
- W4313503771 cites W2009403636 @default.
- W4313503771 cites W2009625810 @default.
- W4313503771 cites W2009642568 @default.
- W4313503771 cites W2009663343 @default.
- W4313503771 cites W2010684644 @default.
- W4313503771 cites W2011548502 @default.
- W4313503771 cites W2012299619 @default.
- W4313503771 cites W2014959387 @default.
- W4313503771 cites W2016442330 @default.
- W4313503771 cites W2019036474 @default.
- W4313503771 cites W2021780626 @default.
- W4313503771 cites W2022020872 @default.
- W4313503771 cites W2022247851 @default.
- W4313503771 cites W2023232373 @default.
- W4313503771 cites W2025511842 @default.
- W4313503771 cites W2026657268 @default.
- W4313503771 cites W2026763885 @default.
- W4313503771 cites W2026969324 @default.
- W4313503771 cites W2027425485 @default.
- W4313503771 cites W2028817121 @default.
- W4313503771 cites W2029237266 @default.
- W4313503771 cites W2032635455 @default.
- W4313503771 cites W2033591258 @default.
- W4313503771 cites W2033755911 @default.
- W4313503771 cites W2035642088 @default.
- W4313503771 cites W2042526900 @default.
- W4313503771 cites W2046880218 @default.
- W4313503771 cites W2047761019 @default.
- W4313503771 cites W2048601982 @default.
- W4313503771 cites W2051308868 @default.
- W4313503771 cites W2054366717 @default.
- W4313503771 cites W2055105606 @default.
- W4313503771 cites W2055138784 @default.
- W4313503771 cites W2055359314 @default.
- W4313503771 cites W2055607526 @default.
- W4313503771 cites W2055608377 @default.
- W4313503771 cites W2058359525 @default.
- W4313503771 cites W2060187799 @default.
- W4313503771 cites W2061353939 @default.
- W4313503771 cites W2062097675 @default.
- W4313503771 cites W2063211069 @default.
- W4313503771 cites W2067262664 @default.
- W4313503771 cites W2071416831 @default.
- W4313503771 cites W2075132449 @default.
- W4313503771 cites W2078494597 @default.
- W4313503771 cites W2079567648 @default.
- W4313503771 cites W2079852953 @default.
- W4313503771 cites W2079877332 @default.
- W4313503771 cites W2083410691 @default.
- W4313503771 cites W2084115067 @default.