MCS reflection data collected around Sites 1276 and 1277 (Fig. F8) delineate three distinct crustal zones. The first of these, in the western portion of the SCREECH transect 2 survey, is extended continental crust; at its seaward edge is a probable continental block topped by faulted, possibly prerift sediments. Seaward of the continental crust, a 70-km-wide zone of nearly featureless basement, capped by the U reflection, is observed. Site 1276 was drilled over this zone of transitional crust. Toward the seaward end of this zone of transitional crust, basement topographic relief gradually increases and gives way to a zone of high-relief basement at the seaward end of the SCREECH transect 2 survey. This crust contains the oldest recognized magnetic anomalies (M3, M1, and M0) generated by seafloor spreading. Basement in this domain forms a series of margin-parallel ridges that are highly reflective in the upper 0.5 s of the crust in seismic reflection records. Site 1277 was drilled on one of these basement ridges near Anomaly M1. In future studies, interpretations of the SCREECH geophysical data will be used in conjunction with Leg 210 drilling results to constrain the evolution of rifting and early seafloor spreading in the Newfoundland–Iberia rift.