Lopingian (Late Permian) high-resolution conodont biostratigraphy in Iran with comparison to South China zonation

AbstractPermian–Triassic boundary (PTB) volcanic ash beds are widely distributed in South China and were proposed to have a connection with the PTB mass extinction and the assemblage of Pangea. However, their source and tectonic affinity have been highly debated. We present zircon U–Pb ages, trace-element and Hf isotopic data on three new-found PTB volcanic ash beds in the western Hubei area, South China. Laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircons yields ages of 252.2 ± 3.6 Ma, 251.6 ± 4.9 Ma and 250.4 ± 2.4 Ma for these three volcanic ash beds. Zircons of age c. 240–270 Ma zircons have negative εHf(t) values (–18.17 to –3.91) and Mesoproterozoic–Palaeoproterozoic two-stage Hf model ages (THf2) (1.33–2.23 Ga). Integrated with other PTB ash beds in South China, zircon trace-element signatures and Hf isotopes indicate that they were likely sourced from intermediate to felsic volcanic centres along the Simao–Indochina convergent continental margin. The Qinling convergent continental margin might be another possible source but needs further investigation. Our data support the model that strong convergent margin volcanism took place around South China during late Permian – Early Triassic time, especially in the Simao–Indochina active continental margin and possibly the Qinling active continental margin. These volcanisms overlap temporally with the PTB biocrisis triggered by the Siberian Large Igneous Province. In addition, our data argue that the South China Craton and the Simao–Indochina block had not been amalgamated with the main body of Pangea by late Permian – Early Triassic time.

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Restudy of the Llandovery conodont biostratigraphy in the Xiushan area, Chongqing City, China

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2015-0189 ◽

2016 ◽

Vol 53 (7) ◽

pp. 651-659

Author(s):

Zhongyang Chen ◽

Chengyuan Wang ◽

Ru Fan

Keyword(s):

South China ◽

Main Part ◽

Yangtze Platform ◽

Conodont Biostratigraphy ◽

Lower Member ◽

Chongqing City

Previous studies of conodonts suggested that the upper member of the Xiushan Formation (late Llandovery) corresponds to the Pterospathodus eopennatus Superbiozone, but no data were obtained from the lower member in the Xiushan area. In this study, the entire Xiushan Formation was resampled from the Datianba section in the Xiushan area of Chongqing City on the Yangtze Platform in South China. In total, 40 samples were collected and processed. Fifteen of these samples contained identifiable conodont specimens. The present study indicates that the lower member and main part of the upper member of the Xiushan Formation correspond to the Pterospathodus eopennatus Superbiozone, while the top of the upper member probably correlates with the Pterospathodus celloni Superbiozone.

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Carboniferous conodont biostratigraphy of the Dianzishang section, Zhenning, Guizhou, South China

Geological Magazine ◽

10.1017/s0016756813000344 ◽

2013 ◽

Vol 151 (2) ◽

pp. 311-327 ◽

Cited By ~ 9

Author(s):

YUPING QI ◽

KEYI HU ◽

QIULAI WANG ◽

WEI LIN

Keyword(s):

South China ◽

North American ◽

Primitive Form ◽

Conodont Biostratigraphy ◽

The World ◽

Kasimovian Stage ◽

Moscovian Stage ◽

Stage Boundaries ◽

Serpukhovian Stage ◽

Bashkirian Stage

AbstractA preliminary summary of the lower Visean to uppermost Moscovian (Carboniferous) conodont succession and biostratigraphy of the Dianzishang section in Zhenning, Guizhou, South China is presented. Eleven conodont zones, in ascending order, can be recognized:Gnathodus praebilineatus,Gnathodus bilineatus,Lochriea ziegleri,Declinognathodus noduliferus,Neognathodus symmetricus, ‘Streptognathodus’expansus(primitive form), ‘Streptognathodus’expansus,Mesogondolella donbassica – Mesogondolella clarki,Idiognathodus podolskensis,Swadelinafauna andIdiognathodus swadeizones. The first occurrences ofLochriea ziegleriat the base of the Serpukhovian Stage,Declinognathodus noduliferus noduliferusat the base of the Bashkirian Stage and ‘Streptognathodus’expansusat the base of the Moscovian Stage are recognized. The definitions of these stage boundaries, as well as that of the base of the Kasimovian Stage are discussed. Correlations with the Naqing section in South China, Russian and North American sections, as well as other important sections in the world, are considered.

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