Quaternary depositional patterns and sea-level fluctuations, northeastern North Carolina Peter R. Parham a, ⁎ , Stanley R. Riggs a , Stephen J. Culver a , David J. Mallinson a , John F. Wehmiller b a Geology Department, East Carolina University, Greenville, NC 27858, USA b Geology Department, University of Delaware, Newark, DE 19716, USA Received 26 December 2005 Available online 21 August 2006 Abstract A detailed record of late Quaternary sea-level oscillations is preserved within the upper 45 m of deposits along an eight km transect across Croatan Sound, a drowned tributary of the Roanoke/Albemarle drainage system, northeastern North Carolina. Drill-hole and seismic data reveal nine relatively complete sequences filling an antecedent valley comprised of discontinuous middle and early Pleistocene deposits. On interfluves, lithologically similar marine deposits of different sequences occur stacked in vertical succession and separated by ravinement surfaces. Within the paleo-drainage, marine deposits are separated by fluvial and/or estuarine sediments deposited during periods of lowered sea level. Foraminiferal and molluscan fossil assemblages indicate that marine facies were deposited in a shallow-marine embayment with open connection to shelf waters. Each sequence modifies or truncates portions of the preceding sequence or sequences. Sequence boundaries are the product of a combination of fluvial, estuarine, and marine erosional processes. Stratigraphic and age analyses constrain the ages of sequences to late Marine Isotope Stage (MIS) 6 and younger (∼ 140 ka to present), indicating multiple sea-level oscillations during this interval. Elevations of highstand deposits associated with late MIS 5 and MIS 3 imply that sea level was either similar to present during those times, or that the region may have been influenced by glacio-isostatic uplift and subsidence. © 2006 University of Washington. All rights reserved. Keywords: Late Quaternary; Sea-level record; Northeastern North Carolina; Stratigraphy; Antecedent topography Introduction The Mesozoic and Cenozoic deposits of northeastern North Carolina consist of eastward-dipping, seaward-thickening se- quences of sediments that form a sedimentary wedge 1.5 to 2.0 km thick (Popenoe, 1985; Klitgord et al., 1988; Riggs et al., 1992). The upper 55 to 60 m of these sediments are Quaternary in age and rest unconformably on the Pliocene Yorktown Formation (Brown et al., 1972; Mallinson et al., 2005). Between the Cape Lookout High to the south and the Norfolk Arch to the north, Quaternary deposits fill a regional depositional basin called the Albemarle Embayment (Ward and Strickland, 1985; Riggs et al., 1995; Foyle and Oertel, 1997)(Fig. 1). The Quaternary section preserved within the Albemarle Embayment is unusually thick for the region. To the north, Quaternary deposits in the Salisbury Embayment of Virginia average 30–35 m in thickness (Foyle and Oertel, 1997). To the south, Quaternary deposits on the Carolina Platform High (Fig. 1) are only preserved as a thin, discontinuous sand prism (Hine and Snyder, 1985). Dissect- ing the Albemarle Embayment are a series of Quaternary fluvial valleys filled with younger coastal and shelf sediments separated laterally by older stratigraphic units that compose the interfluves (Riggs et al., 1995). Located within the modern coastal system of northeastern North Carolina, Croatan Sound and Roanoke Sound (Fig. 1) represent two drowned lateral tributaries that flowed north- wards to the paleo-Roanoke River (now Albemarle Sound) (Riggs et al., 1992). Roanoke Island is a remnant of the Quaternary Research 67 (2007) 83 – 99 www.elsevier.com/locate/yqres ⁎ Corresponding author. Fax: +1 252 328 4391. E-mail address: prp0609@mail.ecu.edu (P.R. Parham). 0033-5894/$ - see front matter © 2006 University of Washington. All rights reserved. doi:10.1016/j.yqres.2006.07.003