Precise age for the Permian–Triassic boundary in South China from high-precision U-Pb geochronology and Bayesian age–depth modeling

Abstract

Abstract. This study is based on zircon U-Pb ages of 12 volcanic ash layers and volcanogenic sandstones from two deep water sections with conformable and continuous formational Permian–Triassic boundaries (PTBs) in the Nanpanjiang Basin (South China). Our dates of single, thermally annealed and chemically abraded zircons bracket the PTB in Dongpan and Penglaitan and provide the basis for a first proof-of-concept study utilizing a Bayesian chronology model comparing the three sections of Dongpan, Penglaitan and the Global Stratotype Section and Point (GSSP) at Meishan. Our Bayesian modeling demonstrates that the formational boundaries in Dongpan (251.939 ± 0.030 Ma), Penglaitan (251.984 ± 0.031 Ma) and Meishan (251.956 ± 0.035 Ma) are synchronous within analytical uncertainty of ∼ 40 ka. It also provides quantitative evidence that the ages of the paleontologically defined boundaries, based on conodont unitary association zones in Meishan and on macrofaunas in Dongpan, are identical and coincide with the age of the formational boundaries. The age model also confirms the extreme condensation around the PTB in Meishan, which distorts the projection of any stratigraphic points or intervals onto other more expanded sections by means of Bayesian age–depth models. Dongpan and Penglaitan possess significantly higher sediment accumulation rates and thus offer a greater potential for high-resolution studies of environmental proxies and correlations around the PTB than Meishan. This study highlights the power of high-resolution radio-isotopic ages that allow a robust intercalibration of patterns of biotic changes and fluctuating environmental proxies and will help recognizing their global, regional or local significance.

High-precision U–Pb ages in the early Tithonian to early Berriasian and implications for the numerical age of the Jurassic–Cretaceous boundary

“…For instance, the biostratigraphy of drill core 1213B poses problems. Bown (2005) pointed out that the sediments of this core are devoid of age-diagnostic NK1 nannofossils such as Conusphaera and Nannoconus. Important markers such as the family Cretarhabdaceae are present but in rare occurrences.…”

Aras Valley (northwest Iran): high-resolution stratigraphy of a continuous central Tethyan Permian–Triassic boundary section

“…In the last 30 years, biostratigraphic (Kozur, 2004a(Kozur, , 2005(Kozur, , 2007bMette and Mohtat-Aghai, 2004;Richoz et al, 2010;Shen and Mei, 2010) and chemostratigraphic data (Holser and Magaritz, 1987;Baud et al, 1989;Korte et al, 2004;Korte and Kozur, 2005;Kakuwa and Matsumoto, 2006;Richoz, 2006;Horacek et al, 2007b;Richoz et al, 2010;Sedlacek et al, 2014) for the Ali Bashi and Zal sections were published in a number of articles. A revision of brachiopod, conodont, and ammonoid stratigraphy of the sections near Julfa was done by Ghaderi et al (2014aGhaderi et al ( , b, 2015, Korn et al ( , 2019a, and Korn and Ghaderi (2019).…”

“…The carbon isotope composition of bulk micritic rock has become an important correlative tool for the PTB strata (Scholle and Arthur, 1980;Jenkyns and Clayton, 1986;Baud et al, 1989;Korte and Kozur, 2010). Global correlative schemes based on these chemostratigraphic records hinge on the observation that the isotope signal traces the ancient oceanic dissolved carbonate (DIC)-carbon isotope composition (Kump, 1991;Dickens et al, 1995).…”

“…Dorasham in Nakhichevan, Azerbaijan (e.g. Arakelyan et al, 1965;Rostovtsev and Azaryan, 1973;Kotlyar et al, 1983;Baud et al, 1989;Zakharov, 1992);…”

Palaeoenvironments and elemental geochemistry across the marine Permo‐Triassic boundary section, Guryul Ravine (Kashmir, India) and a comparison with other North Indian passive margin sections

“…The greatest extinction in the geological record took place at the end of the Permian around 252 Ma (Baresel et al, 2017), supposedly killing over 90% of all marine species, (though this may be may be 81% according to Stanley, 2016), and about 70% of all terrestrial species (Erwin, 2006). Both gradual environmental and catastrophic events have been used to explain the extinction but so far with little consensus (Wignall, 2015).…”