Upper middle to upper Miocene seismic sequences, New Jersey middle to outer continental shelf

The Miocene stratigraphic succession on the middle to outer continental shelf off New Jersey, immediately south of the Hudson Canyon, is examined using high-resolution 2D multichannel seismic (MCS) and log data to evaluate sequence stratigraphic models, aided by results of Integrated Ocean Drilling Program (IODP) Expedition 313. High sedimentation, associated with extensive progradation and aggradation, provides a higher resolution record in this region than elsewhere on the shelf. The study of 29 MCS profiles and 4 gamma-ray logs identified and loop- correlated 14 Miocene sequences. Based on log interpretations, highstand systems tracts are associated with most of these 14 sequences; only 3 (sequences A, C, D) exhibit lowstand and transgressive systems tracts.;Topset and foreset deposits on the middle to outer continental shelf are thicker than those on the inner shelf due to pronounced aggradation and progradation. This pattern is attributed to middle to late Miocene deltaic progradation and migration combined with sediment compaction and loading that created the accommodation space for these especially thick shallow-marine deposits.;Seismic profiles provide a means of anticipating sedimentary facies based on the vertical and lateral arrangement of reflectors within sequences, even in the absence of geologic samples and wireline log measurements. This study evaluates models of sequence stratigraphic evolution by utilizing high sedimentation rates, gamma-ray logs and seismic profiles available in this area. Sequence A shows the importance of drill site data. Using cores and logs, IODP Exp313 showed the maximum flooding surface is the first major downlap surface within sequence A, implying this interval is dominated by thick highstand deposits. By contrast, the widely cited Exxon model predicts that this and all sequences have thick lowstand units containing multiple flooding surfaces, overlain by comparatively thin highstand deposits. Furthermore, the present study showed not all sequences are alike. Shell-632 gamma-ray data reveals thick lowstand and transgressive strata in sequence D, and thin highstand strata consistent with the Exxon model. In contrast, many other sequences examined here have thin lowstand and transgressive systems tracts either below seismic resolution or absent, and thick highstand systems tracts that agree with the model built on Expedition 313 studies.