Modification of the Quaternary stratigraphic framework of the inner-continental shelf by Holocene marine transgression : an example offshore of Fire Island, New York
Date
2014-07-03Author
Schwab, William C.
Concept link
Baldwin, Wayne E.
Concept link
Denny, Jane F.
Concept link
Hapke, Cheryl J.
Concept link
Gayes, Paul T.
Concept link
List, Jeffrey H.
Concept link
Warner, John C.
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/6898As published
https://doi.org/10.1016/j.margeo.2014.06.011DOI
10.1016/j.margeo.2014.06.011Keyword
Seafloor mapping; Inner-continental shelf; Shoreface; Sand ridges; Sorted bedforms; Sediment transport; Ravinement surface; Quaternary stratigraphyAbstract
The inner-continental shelf off Fire Island, New York was mapped in 2011 using interferometric sonar and high-resolution chirp seismic-reflection systems. The area mapped is approximately 50 km long by 8 km wide, extending from Moriches Inlet to Fire Island Inlet in water depths ranging from 8 to 32 m. The morphology of this inner-continental shelf region and modern sediment distribution patterns are determined by erosion of Pleistocene glaciofluvial sediments during the ongoing Holocene marine transgression; much of the shelf is thus an actively forming ravinement surface. Remnants of a Pleistocene outwash lobe define a submerged headland offshore of central Fire Island. East of the submerged headland, relatively older Pleistocene outwash is exposed over much of the inner-continental shelf and covered by asymmetric, sorted bedforms interpreted to indicate erosion and westward transport of reworked sediment. Erosion of the eastern flank of the submerged Pleistocene headland over the last ~ 8000 years yielded an abundance of modern sand that was transported westward and reworked into a field of shoreface-attached ridges offshore of western Fire Island. West of the submerged headland, erosion of Pleistocene outwash continues in troughs between the sand ridges, resulting in modification of the lower shoreface. Comparison of the modern sand ridge morphology with the morphology of the underlying ravinement surface suggests that the sand ridges have moved a minimum of ~ 1000 m westward since formation. Comparison of modern sediment thickness mapped in 1996–1997 and 2011 allows speculation that the nearshore/shoreface sedimentary deposit has gained sediment at the expense of deflation of the sand ridges.
Description
This paper is not subject to U.S. copyright. The definitive version was published in Marine Geology 355 (2014): 346–360, doi:10.1016/j.margeo.2014.06.011.
Collections
Suggested Citation
Marine Geology 355 (2014): 346–360Related items
Showing items related by title, author, creator and subject.
-
Observations of cross-shelf flow driven by cross-shelf winds on the inner continental shelf
Fewings, Melanie R.; Lentz, Steven J.; Fredericks, Janet J. (American Meteorological Society, 2008-11)Six-yr-long time series of winds, waves, and water velocity from a cabled coastal observatory in 12 m of water reveal the separate dependence of the cross-shelf velocity profile on cross-shelf and along-shelf winds, waves, ... -
Cross-shelf circulation and momentum and heat balances over the inner continental shelf near Martha's Vineyard, Massachusetts
Fewings, Melanie R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-09)The water circulation and evolution of water temperature over the inner continental shelf are investigated using observations of water velocity, temperature, density, and bottom pressure; surface gravity waves; wind ... -
The effect of stratification on wind-driven, cross-shelf circulation and transport on the inner continental shelf
Horwitz, Rachel M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2012-06)Observations from a three-year field program on the inner shelf south of Martha's Vineyard, MA and a numerical model are used to describe the effect of stratification on inner shelf circulation, transport, and sediment ...