GSA Annual Meeting in Denver, Colorado, USA - 2016

Paper No. 161-14
Presentation Time: 9:00 AM-6:30 PM

DISTINGUISHING COASTAL SILICICLASTIC SUBENVIRONMENTS USING MODERN FORAMINIFERAL ASSEMBLAGES: BEAR ISLAND AND BOGUE BANKS, NORTH CAROLINA


SHMORHUN, Nina1, CULVER, Stephen J.1, FARRELL, Kathleen M.2, MALLINSON, David J.1 and RIGGS, Stanley R.1, (1)Department of Geological Sciences, East Carolina University, 101 Graham Building, Greenville, NC 27858, (2)North Carolina Geological Survey, Coastal Plain Office and Core Repository, 1620 Mail Service Center, Raleigh, NC 27699-1620, shmorhunn16@students.ecu.edu

Distinguishing coastal siliciclastic subenvironments using sedimentological and geophysical criteria is challenging due to similar lithologies within shoreface and barrier island settings. An additional proxy is required to aid environmental discrimination. Foraminifera are widely used to reconstruct paleoenvironments; however, no current datasets exist that characterize the onshore to offshore foraminiferal assemblages of specific siliciclastic coastal subenvironments in a barrier island setting. This study provides a dataset of foraminiferal assemblages for 26 modern subenvironments of Bear Island and Bear Inlet, NC. Twelve sites were sampled from the barrier island, and 14 sites were sampled from the flood-tide and ebb-tide deltas of Bear Inlet. In addition, sedimentological descriptions for each location were made using photographs and descriptions of sedimentary structures. Grain-size statistics were calculated for replicate samples at each collecting site. These modern datasets will be used to test the hypothesis that coastal subenvironments can be distinguished in Holocene sediments obtained by vibracoring in shoreface and inlet environments of the adjacent Bogue Banks and Bogue Inlet. Preliminary results indicate distinctive foraminiferal assemblages in the upper and lower foreshore.