Open AccessOrganic carbon isotope values from the Late Permian Seis/Siusi succession (Dolomites, Italy): Implications for palaeoenvironmental changes
Author(s) -
Siegert Susann,
Kraus Sonja H.,
Mette Wolfgang,
Struck Ulrich,
Korte Christoph
Publication year - 2011
Publication title -
fossil record
Language(s) - English
Resource type - Journals
eISSN - 1860-1014
pISSN - 1435-1943
DOI - 10.1002/mmng.201100008
Subject(s) - permian , organic matter , geology , isotopes of carbon , carbonate , paleontology , total organic carbon , delta , sedimentary organic matter , stable isotope ratio , sedimentary rock , chemistry , environmental chemistry , physics , organic chemistry , structural basin , quantum mechanics , astronomy
The Permian‐Triassic boundary is marked by a globally prominent negative carbon isotope excursion traceable in marine carbonates and organic matter. In the shallow marine carbonate succession at Seis/Siusi (Dolomites, Italy), the δ 13 C carb and δ 13 C org signatures follow the general Permian‐Triassic boundary carbon isotope trend, but the δ 13 C org values are slightly less depleted in 13 C in two episodes representing restricted lagoonal environments and in the period around the Tesero Oolite Horizon. This isotopically less depleted organic matter in the lagoons is interpreted to be most likely caused by poor oxygen ventilation and/or slightly modified salinity which may have led to restricted bioproductivity and increased hence the relative amounts of continental‐sourced organic matter. In addition, elevated riverine influx and supply of terrestrial organic matter, perhaps triggered by a wet period, might be the cause for the relatively less depleted 13 C in the organic matter around the Tesero Oolite Horizon and in overlying sediments. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)