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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 68 (1984)

Issue: 4. (April)

First Page: 533

Last Page: 533

Title: Tectonic Development of Baltimore Canyon Trough: ABSTRACT

Author(s): B. Ann Swift, C. Wylie Poag, Dale S. Sawyer, John A. Grow


New well data and a new gravity model across the southern end of Baltimore Canyon Trough provide a more complete history of the basin's tectonic evolution and deep crustal structure than was previously known. The basin, which formed during the separation of North America from Africa, narrows and shallows along strike, as basement depth decreases from about 18 km (59,000 ft) in the north near New York to about 4-6 km (13,123-19,685 ft) in the south near Cape Hatteras. Previous Previous HitanalysisNext Hit of the Continental Offshore Stratigraphic Test (COST) B2 and B3 wells using "backstripping" techniques showed a seaward increase in the amount of stretching during the basin's formation. The new biostratigraphic and Previous HitpaleoenvironmentalTop interpretations are from the USGS Island Beach well 1 jus landward of the hinge zone in the basin. This well, along with the COST B2 and B3 data, provides a sampling of the sedimentary sections overlying continental, transitional (rift-stage), and oceanic crust. The subsidence histories derived from these data give a cross-sectional view of the basin's evolution.

A gravity model of the southern end of the basin, along USGS multi-channel seismic line 28, primarily analyzes a 60-mgal shelfedge anomaly. This anomaly reflects the change in bathymetry and more important a change toward the continent in underlying crustal thickness from typical oceanic to thinned continental crust. The crustal thinning is compared to the broad thinning zone to the north. Well-defined rift structures on the landward edge of the basin are modeled as rift grabens near the hinge zone.

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