2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)

Paper No. 26-7
Presentation Time: 9:30 AM

REFINING THE EDIACARAN-CAMBRIAN TRANSITION IN WESTERN MONGOLIA AND SOUTH CHINA


SMITH, Emily F., Earth and Planetary Sciences, Harvard University, 20 Oxford St, Cambridge, MA 02138, MACDONALD, Francis A., Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138, PETACH, Tanya N., Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, ZHU, Maoyan, State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing, 210008, China, LI, Guoxiang, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, 210008, China and BOLD, Uyanga, Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138

The Ediacaran-Cambrian transition is one of the most fundamental biological transitions in Earth History, recording the abrupt appearance and diversification of multiple metazoan clades. However, despite its importance, integrating, characterizing and precisely calibrating biological and geochemical changes across this transition has proven to be difficult, due in part to uncertainties in correlations between records globally and a lack of absolute age constraints.

The Zavkhan Basin in western Mongolia hosts well-exposed, thick, carbonate-rich, fossiliferous late Ediacaran through early Cambrian strata. These successions provide an excellent record of the geochemical and paleontological changes that occur during this time. However, without absolute age constraints from the Zavkhan Basin, it is necessary to use relative dating techniques to correlate between sections in Mongolia with those elsewhere. South China is one such region that not only contains U-Pb ash ages, but also small shelly fossils, and carbon isotope chemostratigraphic data, allowing for the potential to refine the correlation between these two regions.

Here we present high resolution carbon isotope chemostratigraphy from multiple sections across the Zavkhan Basin and use these to create a refined age model for the late Ediacaran through early Cambrian strata. Using this refined age model and new geological mapping, we refine the small shelly fossil biostratigraphic record for this basin. Finally, we correlate these refined records from Mongolia with those from South China to better characterize the Precambrian-Cambrian boundary in Asia and tempo of the Cambrian explosion of metazoan diversity.

Session No. 26

T236. The Ediacaran-Cambrian Ecosphere (R)evolution: Emerging Records from Central and East Asia
Sunday, 19 October 2014: 8:00 AM-12:00 PM
207 (Vancouver Convention Centre-West)
Geological Society of America Abstracts with Programs. Vol. 46, No. 6, p.86
© Copyright 2014 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.
Back to: T236. The Ediacaran-Cambrian Ecosphere (R)evolution: Emerging Records from Central and East Asia
<< Previous Abstract | Next Abstract >>