Sequence stratigraphic analysis of early and middle Miocene shelf progradation along the New Jersey margin

This dissertation uses sequence stratigraphic analysis to study the early to middle Miocene growth of the New Jersey margin, particularly the connection between relative sea level change and variable sediment supply in sequence architecture and preservation. Previous studies of the New Jersey Mid Atlantic margin have concentrated either onshore through extensive coring and few seismic profiles or the outer continental shelf and slope where excellent seismic profiles but limited cores exist. The R/V Cape Hatteras ( CH0698) high resolution seismic data fills the missing interval between the two databases thereby forming a tie between onshore coreholes and offshore shelf seismic profiles. Eleven candidate sequence boundaries were identified by seismic reflector termination geometries in high resolution MCS profiles and traced across the inner margin. ODP Leg 150X onshore coreholes were matched by geophysical log signatures and lithologic changes to offshore boreholes within the seismic grid. Sequence analysis at these drill sites were then matched to the seismic sequence boundaries and drill hole chronologies were used to assign ages to the intervening seismic sequences. A single land-based seismic profile reveals reflector geometries tied to lower Miocene litho- and bio-facies at the Island Beach borehole thereby providing ground truth for seismic facies interpretations. Offshore seismic facies correlate well with paleoenvironmental interpretations of borehole lithologies.;Regional early Miocene sequences correlate globally and suggest a dominant role of global sea-level change. However sequence formation and preservation was controlled by localized sediment contribution and the wave and current regime along the New Jersey Mid Atlantic margin. Lowstand deposits were regionally restricted and point to both single and multiple sediment sources. Transgressive sediments are thin and generally below seismic resolution. Highstand deposit form a more regional sedimentary blanket and document redistribution by along shelf currents. Fluvial incision is limited and generally found far from the clinoform inflection point. No evidence suggests that sea level fell below the elevation of the clinoform inflection point thereby exposing the entire paleoshelf. Efficient cross shelf sediment transport mechanisms account for the extensive lowstand deposits seaward of this inflection point.