Southeastern Section - 63rd Annual Meeting (10–11 April 2014)

Paper No. 5
Presentation Time: 1:00 PM-5:00 PM

PALEOENVIRONMENTAL STUDY OF LATE HOLOCENE, ORGANIC-RICH DEPOSITS RECOVERED FROM PINK BEDS, A SOUTHERN APPALACHIAN WETLAND IN WESTERN NC


WILLIAMS, Michael1, COGBURN, Cullen1, COKER, Michele1, BRITTAIN, Ashley1 and TANNER, Benjamin R.2, (1)Dept. of Geosciences and Natural Resources, Western Carolina University, 331 Stillwell Bldg, Cullowhee, NC 28723, (2)Geosciences & Natural Resources, Western Carolina University, Cullowhee, NC 28723, mawilliams16@catamount.wcu.edu

The timing of late Holocene climate events is not well constrained for the Southern Appalachians because of a general lack of deposits that preserve a record of environmental change. A wetland site was sampled and processed using a multi-proxy approach in order to provide a high resolution temporal reconstruction of environmental change for the Southern Appalachians. Wetlands in this region generally occupy valleys within mountainous landscapes that are remote and isolated. In this study bulk density, percent organic carbon, macroscopic charcoal, C/N ratios, C isotope values, and peat humification analysis are used to reconstruct past environmental conditions. Pink Beds, the studied wetland site, is located within Pisgah National Forest, (35° 21’ 40.45” N 82° 45’ 39.91” W) at an elevation of approximately 970.0 m. The site contains a stream with exposed layers of organic material on the cut banks. The site was probed in order to identify the thickest accumulation of organic matter. A one meter, organic sediment rich core was recovered from the site and the basal deposit was radiocarbon dated. A conventional (corrected) radiocarbon age of 680±30 B.P. was obtained. Charcoal counts show some variation in fire frequency over the time period studied and correlate with C/N ratios, which fluctuate between lower values, suggesting more algal input and wetter conditions, and higher values, suggesting increased vascular plant contributions. δ13C values show that C3 plants are the dominant source of organic matter to the sediment pool. The Pink Beds site does not record a response to known late Holocene climate events, such as the Little Ice Age, suggesting that their influence may not have been felt in the Southern Appalachians.