A recent 48-channel seismic reflection profile (U.S. Geological Survey line 25) extends 330 km southeast off southern New Jersey and crosses the widest and deepest part of the Baltimore Canyon Trough (10 km southwest of the COST B-3 well). The profile has been migrated and converted to depth to reveal the deep sedimentary and basement structures across the ocean-continent transition zone. The sedimentary wedge thickens from 5 km nearshore to 17 km just landward of the East Coast Magnetic Anomaly (ECMA; 20 km landward of the shelf edge in this area). A strong, flat reflector about 10 km wide exists at a depth of 14 km, directly beneath ECMA. Acoustic basement becomes obscure and appears to rise to a depth of 5 km over the next 40 km to the southeast, beneath a Jurassic and lower Cretaceous carbonate shelf-edge complex which extends 20 km seaward of the present shelf edge. Landward-dipping continental rise sediments exist to a depth of at least 13 km on the seaward side of the Jurassic shelf edge. The top of oceanic basement is first seen as a set of prominent hyperbolic reflectors about 50 km seaward of the Jurassic shelf edge, where it occurs at 11 km depth and dips gently landward. It is obscured landward of this point by the prominent middle Jurassic (J₃) horizon.

A Jurassic and lower Cretaceous shelf-edge carbonate platform or reef complex prograded 40 km out over oceanic crust in this area. Greater differential subsidence and compaction of the basin west of the ECMA have produced back-tilted and arched horizons in the Jurassic and lower Cretaceous shelf edge units, creating a 20-km-wide anticline with 500-m closure beneath the upper continental slope. Other lines to the southwest indicate the anticlinal arch extends at least 40 km to the southwest. Similar "slope anticline" structures have been reported off northwest Africa.

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