Southeastern Section–55th Annual Meeting (23–24 March 2006)

Paper No. 6
Presentation Time: 3:20 PM

COMPOUND SPECIFIC ISOTOPIC ANALYSIS OF N-ALKANES AND DISTRIBUTIONS OF FORAMINIFERA FROM FOUR MAINE, USA SALT MARSH SITES RECORD MARSH RESPONSES TO FREQUENT LATE HOLOCENE DISTURBANCE


TANNER, Benjamin, Geosciences & NRM, Western Carolina University, 349 Stillwell Bldg, Cullowhee, NC 28723, UHLE, Maria E., Polar Research Board, The National Academies, Washington DC, 20001 and MORA, Claudia I., Earth and Planetary Sciences, Univ of Tennessee, Knoxville, TN 37996-1410, btanner@email.wcu.edu

A record of late Holocene sediment, foraminiferal, compound specific carbon isotope, and organic geochemical stratigraphy is presented for a series of radiocarbon-dated cores from four Maine, USA salt marsh sites. Though we present some evidence for correspondence between foraminiferal records, that indicate mean high water, and carbon isotope values, that record plant community fluctuations (p<0.05), there are also significant excursions in isotope values within specific foraminiferal zones. These excursions are not predictable, do not correspond between field sites, and cannot be related with any confidence to environmental variables. We suggest that salt marshes in Maine regularly undergo a major change in water level, photosynthetic plant community, or sediment influx. We question the recent use of salt marshes as recorders of ancient climate change and urge caution in the interpretation of marsh plant community records.