The Xiaoyangqiao section, Dayangcha, North China:the new global Auxiliary Boundary Stratotype Section and Point (ASSP) for the base of the Ordovician System
| Autor: | Jörg Maletz, Xiaofeng Wang, Chuanshang Wang, Yuping Qi, Elena G. Raevskaya, Chunbo Yan, Gabriella Bagnoli, Svend Stouge |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
GSSP
Auxiliary Boundary Stratotype Section and Point JILIN-PROVINCE North china ASSP section Boundary (topology) Ordovician System STRATIGRAPHY TRILOBITE Base (topology) EVOLUTION GREEN POINT Paleontology Stratotype Section (archaeology) GRAPTOLITE CONODONT IAPETOGNATHUS 500 Naturwissenschaften und Mathematik::550 Geowissenschaften Geologie::550 Geowissenschaften Ordovician General Earth and Planetary Sciences Point (geometry) NEWFOUNDLAND Geology SEA-LEVEL |
| Zdroj: | Wang, X, Stouge, S, Maletz, J, Bagnoli, G, Qi, Y, Raevskaya, E G, Wang, C & Yan, C 2021, ' The Xiaoyangqiao section, Dayangcha, North China : the new global Auxiliary Boundary Stratotype Section and Point (ASSP) for the base of the Ordovician System ', Episodes, vol. 44, no. 4, pp. 359-383 . https://doi.org/10.18814/epiiugs/2020/020091 |
| DOI: | 10.18814/epiiugs/2020/020091 |
| Popis: | In 2019 the Sub-Commission on the Ordovician System approved the Xiaoyangqiao section, North China as a new ASSP section for the base of the Ordovician System. The sedimentary succession of the section is exposed in a natural outcrop near the Dayangcha Village at a position of 42 degrees 3'24 '' N, 126 degrees 42'21 '' E. It has a well-preserved, abun-dant and diverse fossil record across the boundary with key markers (conodonts and graptolites), which provide improved intercontinental correlation of the Cambrian- Ordovician boundary. The appearance of the first plank -tonic graptolites is immediately below the base of the Cordy-lodus lindstromi Conodont Zone. Other fossils, including acritarchs, brachiopods and trilobites are also present in the Xiaoyangqiao ASSP section. Non-biotic secondary global markers near the base of the Ordovician System include a positive carbon isotopic excursion with the maximum peak (named HSS) below the boundary, a prominent unnamed negative peak immediately below the boundary and a prominent carbon isotope excursion with positive peaks above the boundary. The latter excursion is associated with the appearance of the planktonic graptolites in the Ordo-vician. The strength of the Xiaoyangqiao ASSP section is the correlation between the conodonts and graptolites, correspondence of sea-level lowstands, and the matches of geochemical parameters. |
| Databáze: | OpenAIRE |
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