Figure F2. A. Reconstruction of conjugate seismic sections from the Newfoundland and Iberia margins to the time of Anomaly ~M1. Left: Preliminary interpretation of Ewing line 2MCS (location in Fig. F3). Interpreted postrift sediments are shaded. The deep U reflection is highlighted and labeled. Proposed drill sites landward of Anomaly M1 are shown. Right: Composite seismic section (LG-12) along the conjugate Iberia drilling transect, adapted from ODP Leg 173 Scientific Party (1998). Drill sites are numbered, and recovery at the bottom of holes is indicated. B. Conrad MCS line NB1 (location in Fig. F3) ~150 km south of Ewing line 2MCS, showing another view of Newfoundland Basin basement structure and the overlying U reflection. C. IAM-9 MCS line ~50 km south of LG-12 off Iberia. In A–C, note the marked asymmetries in basement depth and roughness between the Newfoundland and Iberia sides of the rift. D. Preliminary interpretation of the full length of Ewing line 2MCS with magnetic anomaly locations of Srivastava et al. (2000) and proposed drill site locations. TWT = two-way traveltime.