Projektbeschreibung Ecological and environmental - Gepris

Ecological and environmental change recorded through stratigraphy and
sedimentology at selected Ediacaran-Cambrian boundary sections in East and
Central Asia
Applicant:
Professor Dr. Christoph Heubeck
Friedrich-Schiller-Universität Jena
Chemisch-Geowissenschaftliche Fakultät
Institut für Geowissenschaften
Burgweg 11
07749 Jena
Telephone: +49 3641 948620
Fax: +49 3641 948622
E-Mail: christoph.heubeck uni-jena.de
Subject Area
Funding
Geology and Palaeontology
Funded from 2007 to 2015
Project Description
We suggest investigating three aspects of sedimentary-stratigraphic change at the Precambrian-Cambrian Boundary
(PCB; ca. 543 Ma) that complement geochemical and paleobiological subprojects: (1) the effects of the agronomic
revolution, recorded by paleoichnology; (2) the significance of karsting at the PCB on the Yangtze Platform; and (3)
the comparative stratigraphic architecture of Ediacaran-Cambrian sections from the Yangtze Platform, the Tarim/Yili
microcontinents, and southern Kazakhstan.(1) The fossil record of Ediacaran to Lower Cambrian shelf deposits
demonstrates how significant volumes of fine-grained sediment became incorporated in the global
chemicaloceanographic interchanges through the demise of microbially sealed surfaces during the agronomic
revolution. To date, the timescale, facies dependency and degree of this enlargement of the Earth system cannot be
incorporated in geochemical modeling calculations nor can it be convincingly linked to the expansion of the metazoa.
In this subproject, we will link the bioturbation index from key sections across the PCB to geochemical proxies and
relate those in turn to the chemostratigraphic record from profiles in West China (Tarim and Yili microcontinents) and
Kazakhstan (Karatau Range).(2) Because the contact between Ediacaran and Cambrian deposits in the fossiliferous
shallow-water facies the Yangtze Platform is virtually everywhere unconformable and karsted, resulting from one or
several periods of relative sea level fall and subaerial exposure of Dengying Fm. carbonates, approximately 6-10 Ma
of critical geologic time at the PCB is apparently missing. This record can be studied in numerous well-exposed
stratigraphic sections of Sichuan, Guizhou and Hubei Provinces. We suggest to assess this event to infer duration and
intensity of chemical weathering and compare our results to other well-exposed PCB reference sections worldwide.
Our results, complemented by a concurrent biostratigraphic study (subproject Steiner), will fill in a neglected but
potentially critical gap in our understanding of the metazoan base-Cambrian radiation in South China.
DFG Programme
Subproject of
International Connection
Participating Person:
Research Units
FOR 736: The Precambrian-Cambrian Biosphere
(R)evolution: Insights from Chinese Microcontinents
China, United Kingdom, United States
Professor Dr. David J. Bottjer; Dr. Simon J. Braddy; Dr.
Hong Hua; Professor Dr. Xiaofeng Wang; Professor Dr.
Jun-Ming Zhang; Dr. Meng-Hua Zhu, Ph.D.
GEPRIS is a project of the Deutsche Forschungsgemeinschaft (DFG)
Contact GEPRIS at http://www.dfg.de/gepris
(c) 1999 - 2017 Deutsche Forschungsgemeinschaft (http://www.dfg.de)