A New Look at Neoproterozoic Earth

Boulder, Colo. - The end of the Proterozoic Eon was marked by tremendous tectonic, climatic, and biological change. In a Pardee Keynote Symposium at the Geological Society of America annual meeting in Seattle next week, scientists will explore a variety of processes underway during the Neoproterozoic, environmental changes they produced, and subsequent emergence of Ediacaran biota and the Cambrian Explosion.

Two talks address the big-picture significance of Neoproterozoic Earth:

• Joseph L. Kirschvink, CalTech, who first articulated the Snowball Earth hypothesis, will present a sweeping new hypothesis linking paleomagnetic, geochemical, and biomolecular data to explain the Cambrian Explosion.
• Bruce Runnegar, Director of the NASA Astrobiology Institute, will discuss how this period of intense interaction between Earth surface processes and the biosphere serves as a testbed for the emerging field of astrobiology.

Controversy regarding the length of time that elapsed between the last major ice age and the emergence of large animals, a significant issue of Neoproterozoic geobiology, is addressed in three talks:

• Samuel Bowring, Massachusetts Institute of Technology, will present new geochronometric data regarding the age and duration of the Gaskiers glaciation. This extremely short-lived glaciation immediately preceeded the evolution of large Ediacaran animals.
• Guy Narbonne, Queen's University, will present new Ediacaran fossils from Newfoundland. Some appeared within five million years after the Gaskiers glaciation, suggesting that large animals developed almost immediately after the last Neoproterozoic glaciation.
• Alan J. (Jay) Kaufman, University of Maryland, will discuss evidence from northern Virginia that also suggests a close link in time between the evolution of large animals and the end of the Neoproterozoic glacial period.

A complete list of session speakers as well as all abstracts may be viewed at:
http://gsa.confex.com/gsa/2003AM/finalprogram/session_9744.htm

Neoproterozoic Geobiology: Fossils, Clocks, Isotopes, and Rocks
Wednesday, Nov. 5, 8:00 a.m.-12:00 p.m., WSCTC Ballroom 6B

CONTACT INFORMATION

Joe Kirschvink
CalTech
626-395-6136
kirschvink@caltech.edu

Bruce Runnegar
NASA Astrobiology Institute
310-206-1738
runnegar@ucla.edu

Samuel Bowring
Massachusetts Institute of Technology
617-253-3775
sbowring@mit.edu

Guy Narbonne
Queen's University
613-533-2597
narbonne@geol.queensu.ca

Alan Kaufman
University of Maryland
301-405-0395
kaufman@geol.umd.edu

During the GSA Annual Meeting, Nov. 2-5, contact Ann Cairns at the GSA Newsroom, Washington State Convention Center and Trade Center, Seattle, for assistance and to arrange for interviews: 206-219-4615.

Geological Society of America
115th Annual Meeting
Nov. 2-5, 2003
Washington State Convention and Trade Center
Seattle, WA, USA

Geological Society of America
www.geosociety.org

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