William P. Dillon Charles K. Paull 1982 <p>Four strong reflection horizons identified on multichannel seismic-reflection profiles of the U.S. continental margin east of the Carolinas have been traced and contoured (maps A-D).&nbsp; Depths, in kilometers, to the horizons were calculated by the method of Taner and Koehler (1969) using the reflection-time and RMS (root-mean-square) velocities from multichannel velocity analyses.&nbsp; The contoured horizons are continuous traceable reflections on the profiles, indicating that they are surfaces of geological significance.&nbsp; A paleoshelf edge and slope exists on all profiles seaward of the present-day slope.&nbsp; Reflectors cannot be traced from the old shelf into the deep sea, and age estimates for the two areas are derived independently.&nbsp; As a result, the horizons contoured on each map cannot by shown to be synchronous, but they are interpreted to be approximately similar in age.&nbsp; The ages assigned to these horizons under the shelf were determined by projecting reflecting horizons to onshore wells (Brown and others, 1972) and, through a network of seismic profiles, to offshore wells north and south of the map area where units have been dated (Dillon and others, 1979a, b; Schlee, 1981; Paull and Dillon, 1980a) Ages of relectors seaward of the paleoshelf edge were determined by tracing the deep-sea reflecting horizons to DSDP (Deep Sea Drilling Project) wells (Klitgord and Grow, 1980; Tucholke and Mountain, 1979; Paull and Dillon, 1980b).</p> application/pdf 10.3133/mf1402 en U.S. Geological Survey Carolina Trough structure contour maps reports