Assessing and Correlating Assemblage Zones in Chinese Terreneuvian Cambrian

Terreneuvian small shelly faunas of East Yunnan (South China) and their biostratigraphic implications

Authors:

1. Ben Yang (a)
2. Michael Steiner (a)
3. Guoxiang Li (b)
4, Helmut Keupp (a)

Affiliations:

a. Department of Earth Sciences, Freie Universität Berlin, Malteserstrasse 74–100, Haus D, Berlin, 12249, Germany

b. State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China

Abstract:

The study discusses the detailed composition of Terreneuvian small shelly fossil (SSF) assemblages of eastern Yunnan Province (Meishucun, Xianfeng and Huize regions). The described sections represent shallow water deposits of the Yangtze Platform that include a number of stratigraphical hiati. The reported SSF assemblages can be assigned to the regional SSF biozones I-III (Anabarites trisulcatus-Protohertzina anabarica Assemblage Zone; Paragloborilus subglobosus-Purella squamulosa Assemblage Zone; Watsonella crosbyi Assemblage Zone). Zones II and III are slightly redefined based on new data. Two subzones of Zone II are proposed here, namely, Annelitellus yangtzensis-Obtusoconus honorabilis Subzone and Maikhanella cambriana–Oelandiella korobkovi Subzone. Claviconchella qianyii gen. et sp. nov. and Bubiites simplex gen. et sp. nov. are reported. Here we also provide a critical revision of the SSF distribution for the well-known Meishucun section. The correlation scheme for East Yunnan documents the extent and duration of stratigraphical hiati. The distribution of SSFs and the lithological characterization indicates three major events of exposure of the carbonate platform resulting in sedimentary breaks and possible karstification. This prompts new consideration of the previously described stable isotope stratigraphy of shallow platform strata. Considering the complexity of the Terreneuvian Earth history as well as the uniqueness of SSF, an integration of sedimentology, geochemistry and palaeontology is needed for future SSF study.