Late Jurassic sedimentation and deformation in the west Iberia continentalmargin: insights from FMS data, ODP Leg 173

In the Iberia Abyssal Plain, Ocean Drilling Program (ODP) Site 1065 drilled the top of a continental tilted block, penetrating a Middle to Late Jurass ic probable pre-rift sedimentary unit. Borehole images of this unit were ob tained by the Formation MicroScanner (FMS) logging tool, thus allowing the identification and 3D measurement of two block tilting phases. The last one is an eastward 15 degrees tilt, probably related to the main Early Cretace ous rifting phase, and consistent with the tilted block image on seismic li nes. The first tilt, previously unknown, is Late Jurassic in age. The block tilting is 15 degrees to the southeast, and is not associated with any not iceable change in the depositional environment. Both tilting episodes induc ed sedimentary instabilities, leading to listric faults and slumps. FMS ima ges also showed that the sediments originated from the north (Galicia Bank) during Late Jurassic times. (C) 2000 Elsevier Science Ltd. All rights rese rved.