HR: 1340h
AN: PP43B-1285    [Abstracts]
TI: A Paleoenvironmental Record From Tomales Bay, California: Organic and Geochemical Proxy Records of Anthropogenic Impacts
AU: * Flores, S C
EM: scflores@ucdavis.edu
AF: University of California, Davis, Department of Geology, 289A Physics/Geology, One Shields Avenue, University of California, Davis, Davis, CA 95616, United States
AU: Hill, T M
EM: tmhill@geology.ucdavis.edu
AF: University of California, Davis, Department of Geology, 289A Physics/Geology, One Shields Avenue, University of California, Davis, Davis, CA 95616, United States
AU: Hernes, P J
EM: pjhernes@ucdavis.edu
AF: University of California, Davis, Department of Land, Air and Water Resources, Veihmeyer Hall, One Shields Avenue, University of California, Davis, Davis, CA 95616, United States
AU: Spencer, R G
EM: rgspencer@ucdavis.edu
AF: University of California, Davis, Department of Land, Air and Water Resources, Veihmeyer Hall, One Shields Avenue, University of California, Davis, Davis, CA 95616, United States
AB: Coastal regions have long attracted human settlement for numerous reasons such as abundant freshwater sources, ecological and mineralogical richness, and the facilitation of trade and transport. To better understand anthropogenic impacts on coastal environments, recent sediment records of Tomales Bay, (California, U.S.A.) were examined. Tomales Bay is a secluded estuary located 50 km north of San Francisco that drains into the Pacific Ocean, for which the anthropogenic history has been very well documented. In recent history Tomales Bay has undergone changes in land-use and an increase in human populations, but impacts of these processes on the marine environment are poorly constrained. Tomales Bay is ~1.4km wide and 20km long, with sedimentation rates of 3-30mm/year. Six push-cores 15 to 20 cm in length were taken at low tide within the bay. Measurements of preserved lignin will provide a record for terrigenous DOM cycling and diagenetic processes occurring in the watershed, while also differentiating between marine and terrigenous OM sources to the sediments. The impact of environmental change over time on the presence of microfossil species (benthic foraminifera) will be presented. Temperature reconstructions and carbon cycling in the bay will be discussed based on oxygen and carbon stable isotope analyses of selected foraminiferal species. This study aims to reconstruct recent environmental changes in Tomales Bay, both natural and anthropogenic to constrain the extent to which human perturbation affects coastal environments.
DE: 1041 Stable isotope geochemistry (0454, 4870)
DE: 3030 Micropaleontology (0459, 4944)
DE: 4217 Coastal processes
DE: 4850 Marine organic chemistry (0470, 1050)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting