Bond, D. P. G.; Wignall, P. B.; Wang, W.; Izon, G.; Jiang, H.-S.; Lai, X.-L.; Sun, Y.-D.; Newton, R. J.; Shao, L.-Y.; Védrine, S. and Cope, H.
The mid-Capitanian (Middle Permian) mass extinction and carbon isotope record of South China.
Palaeogeography, Palaeoclimatology, Palaeoecology, 292(1-2)
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Conodont, C isotope and fossil and facies data are presented for the Capitanian (Middle Permian)mass extinction
record seen in platform carbonates (Maokou and Wuchiaping formations) of South China, where limestones interdigitate with the volcanic succession of the Emeishan large igneous province. The Maokou Formation provides an extinction recordmarked by the loss of keriothecal-walled fusulinaceans and a turnover incalcareous algae. In sections within the Emeishanprovince this crisis occurs at the base of the oldest record of volcanismfrom the Jinogondolella altudaensis conodont zone (of mid-Capitanian age). Around the periphery of the Emeishan
province this extinction level lies within the upper part of the Maokou Formation at a level where platform carbonate deposition was frequently interrupted by thick volcanic ash depositional events. The assemblages of the uppermost Maokou Formation are characterised by typical “Late Permian” taxa although these levels still lie within theMiddle Permian (Guadalupian Series). “Disaster” taxa, such as Earlandia and Diplosphaerina are locally prolifically abundant in the aftermath of the mass extinction. The crisis is particularly noteworthy amongst
photosynthetic taxa such as calcareous algae and fusulinaceans that probably harboured photosymbionts. Therefore, a kill mechanism involving cooling from explosive volcanism and potentially acid rain from sulphate
aerosols appears appropriate. A composite δ13Ccarb curve, calibrated against a high-resolution conodont biostratigraphy reveals a major intra-Capitanian negative excursion (of >5‰) superimposed on typically heavy (4–5‰)Middle Permian values. This curve can also be recognised in Panthalassan seamount carbonates of Japan although this requires reassignment of apparently Upper Permian limestones to the Middle Permian. In both China and Japan the Capitanian mass extinction occurs during the early stage of this major, intra-Capitanian negative excursion. Assuming typical platform carbonate accumulation rates, the records of the Maokou Formation suggest δ13Ccarb values fell at ~0.01‰/kyr suggesting a catastrophic origin (such as gas hydrate destabilisation) is unlikely, although a volcanic source is possible.
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