2011-2012 Schlanger Fellow – Amanda Oehlert

Amanda Oehlert

University of Miami

Decoupling of Organic and Inorganic δ13C Records in Periplatform Sediments: A global phenomenon

Abstract

The relationship between organic (δ¹³C_organic) and inorganic carbon isotope records (δ¹³C_inorganic) is assumed to be a direct correlation. This relationship was not found in periplatform sediments recovered during Leg 166. Periplatform sediments from a mixed carbonate-clastic margin (Leg 133) and a cool-water carbonate platform (Leg 182) will be analyzed for δ¹³C_organic composition, and compared to published δ¹³C_inorganic records to determine the relationship. This study will investigate whether the signal identified at Leg 166 is a local phenomenon, or a globally observable pattern indicative of carbon cycling. These results will have implications for interpretations of global carbon cycling throughout geologic history.

Biography

My interest in geology began during my involvement in the Environmental Fellows Program at the University of Illinois, Urbana-Champaign. For my bachelor’s thesis, I studied the effects of anthropogenic waste on coral morphology on the reefs of Curacao, and discovered a passion for geological systems. Currently, I am starting the third year of my Ph.D. with Professor Peter K. Swart at the University of Miami’s Rosenstiel School of Marine and Atmospheric Sciences.  I am investigating the modern processes that affect the relationship between inorganic (δ¹³C_inorganic) and organic (δ¹³C_organic) carbon isotope records in periplatform sediments. During the next year, I will assess this relationship in cores from the Great Barrier Reef (ODP Leg 133) and the Great Australian Bight (ODP Leg 182) with the goal of gaining an accurate perspective on the processes and mechanisms that influence δ¹³C_inorganic and δ¹³C_organic records at a variety of carbonate margins.