Reconstruction of Tertiary progradation and clinoform development on the New Jersey passive margin by 2-D backstripping

Publication Type  Journal Article
Year of Publication  1999
Authors  Steckler, M. S.; Mountain, G. S.; Miller, K. G.; Christie-Blick, N.
Journal Title  Marine Geology
Volume  154
Issue  1-4
Pages  399-+
Journal Date  Feb
ISBN Number  0025-3227
Accession Number  ISI:000078332800028
Key Words  continental margins; backstripping; sequence stratigraphy; sea level; clinoform; tertiary climate; baltimore canyon trough; sequence stratigraphy; shelf sedimentation; continental-shelf; lithosphere; subsidence; simulation; deposits; isostasy; basins

We have reconstructed the Oligocene to Middle Miocene paleobathymetry and stratigraphy of the New Jersey margin using a modified backstripping technique. By analyzing the geometry of the margin through time, we investigate its response to fluctuating sea level, changing climate, and Variable sediment supply during the Tertiary. The reconstructions reveal a change in the margin morphology from a more steeply dipping (1 :300 to 1 :500) carbonate ramp in the Eocene to a flatter shelf with a sharp shelf edge at present. This was accomplished by an increase in the terrigenous sediment supply that filled available accommodation and caused progradation across the margin. We link the increase in sediment flux with climatic cooling rather than tectonic processes. The progradation is evidenced by a series of clinoforms whose formation was modulated by sea level and which extend over 100 km across the shelf. The height and dip of the clinoforms increased as they extended onto the deeper parts of the earlier ramp. The Miocene clinoform rollovers at the New Jersey margin had water depths of similar to 60-130 m and are interpreted as the edge of a new continental shelf built over the older ramp. Sea-level fall was probably insufficient to drive the Miocene shorelines past the shelf breaks. Thus, measurements of sea-level amplitude based upon 'coastal' onlap over the clinoforms are not reliable. (C) 1999 Elsevier Science B.V. All rights reserved.


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URL  <Go to ISI>://000078332800028