Poster Number 146
See more from this Division: General Discipline Sessions
See more from this Session: Stratigraphy (Posters)
Abstract:
Regional-scale cross sections were prepared by an integration team that worked through consensus to establish correlations using multiple lines of evidence process sedimentology, facies analysis, foraminiferal biofacies, amino acid racemization and carbon-14 ages, geomorphology, and offshore geophysics. The profiles are oriented parallel to: 1) the strike of the barrier island chain; 2) regional strike on the mainland; and 3) a dip section that transects the Suffolk Scarp. Facies identified in core include fluvial, estuarine, barrier island, shoreface, and shelf deposits. Regional reflectors (Q0, Q30, Q50, Q99), mapped along adjacent offshore and backbarrier seismic lines, were projected into cross sections and correlated with unconformities in cores, to define major boundaries and establish the stratigraphic framework.
Q0, Q30, and Q50 are respectively interpreted as the bases of early (1.8 or 2.6ka), middle (780ka) and late (130ka) Pleistocene deposits, and also correspond (respectively) to the lower boundaries of aminozones 4, 3 and 2. Regional correlation models (Mixon and others, 1989) suggest that these reflectors rise and merge landward with early, middle and late Pleistocene shoreline maxima that are associated (respectively) with the Surry Scarp (31m), an unnamed scarp at 14m, and the Suffolk Scarp (10m). Q99 marks the incision at the last glacial maximum, and is overlain by late Pleistocene to Holocene lowstand (LST) and transgressive (TST) deposits.
See more from this Division: General Discipline Sessions
See more from this Session: Stratigraphy (Posters)