Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fulthorpe, C. S. Articles by Mountain, G. S. Search for Related Content GeoRef GeoRef Citation

Morphology and distribution of Miocene slope incisions off New Jersey: Are they diagnostic of sequence boundaries?

¹ University of Texas Institute for Geophysics, 4412 Spicewood Springs Road, Building 600, Austin, Texas 78759-8500, USA
² Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA

High-resolution multichannel seismic reflection profiles confirm that middle–late Miocene continental slope canyons off New Jersey are rare, in contrast to their prevalence on the slope today. Localized canyon incision occurred in two physiographic settings bounded by declivity breaks: steeper clinoform fronts and more shallowly dipping regions seaward of clinoform toes. Canyons incising Miocene clinoform fronts are U and V shaped, relatively small, closely spaced, and localized along strike. They apparently developed independently of known fluvial inputs, although rivers probably discharged sediment near paleo-shelf edges (clinoform breakpoints) during Miocene relative sea-level lowstands. However, not all clinoform fronts are incised; nonchannelized downslope sediment transport also appears to have been a common process. V-shaped canyons are the most common type recognized seaward of clinoform toes; occasional amphitheater-shaped failures also occur. Rare canyons with partly aggradational banks may reflect either overbank and/or levee or contour-current deposition.

Many Miocene canyons definitely incise sequence boundaries; they may all do so. This implies that canyons formed during relative sea-level lowstands, in accord with the classic sequence stratigraphic model of siliciclastic depositional systems. However, depth of incision on clinoform fronts decreases downslope, whereas seaward of toes it decreases upslope; development of canyon systems in the two settings is not linked by a single set of processes. Therefore, the presence or absence of canyon incision on this margin must be dictated not only by fluctuations in sea level, but by subtle changes in local conditions or regime variables. These include the efficiency of downslope sediment transport, rate of sediment supply, grain size, and possible slope collapse related to fluid escape.

Key Words: canyons • clinoforms • Miocene • New Jersey • seismic reflection profiles • sequence stratigraphy

This article has been cited by other articles:

				G. Cantalamessa, C. Di Celma, L. Ragaini, G. Valleri, and W. Landini Sedimentology and high-resolution sequence stratigraphy of the late middle to late Miocene Angostura Formation (western Borbon Basin, northwestern Ecuador) Journal of the Geological Society, May 1, 2007; 164(3): 653 - 665. [Abstract] [Full Text] [PDF]

				Progradation along a deeply submerged Oligocene-Miocene heterozoan carbonate shelf: How sensitive are clinoforms to sea level variations? AAPG Bulletin, October 1, 2003; 87(10): 1547 - 1574.

				Glaucony in Ocean-Margin Sequence Stratigraphy (Oligocene-Pliocene, Offshore New Jersey, U.S.A.; ODP Leg 174A) Journal of Sedimentary Research, July 1, 2001; 71(4): 599 - 607.