Mountain, Gregory and Proust, Jean-Noel (2011): Eustatic history, sequence architecture, and lithofacies successions along the NJ transect; a progress report

Leg/Site/Hole:
IODP 313
Identifier:
2013-032946
georefid

Creator:
Mountain, Gregory
Rutgers University, Department of Earth and Planetary Sciences, Piscataway, NJ, United States
author

Proust, Jean-Noel
CNRS, France
author

Identification:
Eustatic history, sequence architecture, and lithofacies successions along the NJ transect; a progress report
2011
In: Anonymous, Geological Society of America, 2011 annual meeting
Geological Society of America (GSA), Boulder, CO, United States
43
5
374-375
IODP Expedition 313 drilled & logged 3 sites in 35 m of water 45-65 km off New Jersey in May-July 2009. These data constitute a long-awaited "missing link" in a transect of sites from the coastal plain to the continental slope begun in 1993 to 1) calibrate the imprint of baselevel changes on sequence architecture & lithofacies successions, & 2) extract global sea-level history during times of known glaciation. Exp313 sites were located at the rollovers of Oligocene to mid-Miocene clinoforms where this record would be most clearly expressed & was feasible to drill. The tasks of evaluating sequence stratigraphic models, comparing the age of inferred sea-level falls to the delta (super 18) O glacio-eustatic proxy, & estimating the corresponding amplitudes, rates & mechanisms of sea-level change await the completion of several underway studies; here we provide a progress report. 1311 m of very good to excellent quality cores were collected with 80% recovery. The deepest was 757 mbsf; the oldest was upper Eocene. Each hole was located to intersect top-, fore- and/or toeset strata of several clinoforms linked by a grid of high-resolution 2D seismic profiles. Slim-line logs in each hole gathered spectral gamma ray, resistivity, magnetic susceptibility, sonic & acoustic televiewer measurements. Seismic-log-core correlations, strengthened by MultiSensorCoreLogger measurements, enable us to locate samples in the seismic framework with depth uncertainties of only a few meters. Thus we're able to ground-truth lithofacies at a variety of settings in several depositional sequences. Topsets were well sorted silts & sands deposited in offshore to wave- and river-dominated shoreface settings. Toeset silts & silty clays were deposited below storm wave base & typically interbedded with poorly sorted debrites & turbidites deposited at times of clinoform degradation. Geochronologies based on Sr-isotopic ages, biostratigraphy, limited magnetic reversals & pollen markers show accumulation rates of 50-150 m/my with hiatuses across sequence boundaries from 0 to approximately 2 Ma. No conclusive evidence has been found of a sea-level fall below a clinoform rollover, but shoreface deposits along clinoform foresets paired with deep-water facies in topsets of the same sequence imply changes in relative sea level on the order of 60 m.
English
Coverage:Geographic coordinates:
North:39.3900
West:-73.3800East: -73.2400
South:39.3100

Stratigraphy; Atlantic Ocean; Cenozoic; Expedition 313; geophysical methods; geophysical profiles; geophysical surveys; Integrated Ocean Drilling Program; lithofacies; Miocene; Neogene; New Jersey; North Atlantic; Northwest Atlantic; Oligocene; Paleogene; paleogeography; seismic methods; seismic profiles; sequence stratigraphy; surveys; Tertiary; United States;

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