T235 Ocean Chemistry through the Precambrian and Paleozoic II
Wednesday, 10 November 2004
1:30 PM - 5:30 PM
CARBON-ISOTOPE STRATIGRAPHY OF THE MOROCCAN ANTI-ATLAS: EARLY CAMBRIAN CARBON CYCLING AND THE IMPORTANCE OF PHYSICALLY BUFFERED METAZOA
Paper number: T235-4
Program: Technical Sessions
Time: 2:00 PM – 2:15 PM
Authors
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Daniel P. SchragHarvard Univ, Cambridge, MA
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James CrowleyMassachusetts Institute of Technology, Cambridge, MA
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Samuel A. BowringMassachusetts Institute of Technology, Cambridge, MA
Abstract
We present a δ13C record from the Anti-Atlas mountains of Morocco and calibrate the curve using precision U-Pb zircon geochronology of ash beds in the same section. The variations in δ13C of carbonate occur on a wide range of time scales, suggesting that different mechanisms are involved, including methane clathrate destabilization on short (<100 kyr) time scales and changes in nutrient recycling and organic carbon burial on longer (>1 myr) time scales. Through a correlation with more fossiliferous, albeit condensed, sections in Siberia, we examine the pattern of cyclic δ13C variation in the context of the reappearance and diversification of skeletonized metazoa during the Early Cambrian.