Foraminiferal Evolution and Formation of Oolitic Limestone near Permian-Triassic Boundary at Yangou Section,Jiangxi Province
Tian Li
Tong Jinnan
Song Haijun
Liang Lei
Yang Lirong
Song Huyue
Wang Chenggang
Zhao Xiaoming
Sun Dongying
Abstract：The homogeneous carbonate Permian-Triassic boundary section at Yangou records the integrated extinction process of the shallow marine area,which killed over 90%marine invertebrates.This study of foraminifers explores the extinction pattern and deposition progress during the Paleozoic-Mesozoic transition.In total,39 species in 27 genera of foraminifers have been identified,including 7 species in 4 genera of fusulinids.The richness and diversity remarkably decrease at the top of Bed 21-2, marking the disappearance horizon.4 distinct assemblages evolved within the Permian-Triassic boundary beds:the assemblages with low richness and low disparity replaced those with high richness and high disparity.The diversity and assemblage analysis exhibit a rapid decline process at the top of Bed 21-2.Whereas,the mixing of pre-extinction fauna,fusulinids,with post-extinction fauna,Hindeoduschangxingensis,within the oolitic beds,implies that the fossil could be reworked to the shoal by the sea level changes.Meanwhile,the coating of foraminifers and aragonite-calcite cement around the grains indicate a cata-strophic ocean with high water velocity,elevated microbes and carbonate super-saturation.
Keywords：Permian-TriassicforaminiferextinctionYangou Sectionpaleontology
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 1473-1486 )