A seismic comparison of the early stratigraphic evolution of conjugate passive continental margins: the Newfoundland/Flemish basin and the eastern Iberian Abyssal Plain south of Galicia Bank

Abstract

The Newfoundland/Flemish Basin and its conjugate passive margin, the northwestern Iberian Peninsula, were contiguous in the late Early Cretaceous. Therefore, we infer that these margins were subject to similar tectonic and sedimentary processes during their early evolution. A comparison of these conjugates using multichannel seismic-reflection (MCS) profiles shows similar acoustic basement in the Newfoundland/Flemish Basin. Both margins exhibit a high-amplitude, rhythmically layered "rift' sequence bounded at the top by a prominent, high-amplitude sequence boundary interpreted to be a break-up unconformity of late Early Cretaceous age. The early "drift' sequences on both margins consist of lower amplitude, discontinuous reflections to which we assign an early Albian to Cenomanian age. Results of these comparisons support developing correlations between Grand Banks stratigraphy and the deep Newfoundland/Flemish Basin, and are consistent with our current interpretation of the nature of the Newfoundland/Flemish Basin crust and the position of the ocean/continent boundary off this part of eastern Canada. -from Authors