ABSTRACT: Inversion of the Jeanne d'Arc Basin and Implications for the Formation of the Hibernia and Flying Foam Structures

DRISCOLL, NEAL W., GARRY D. KARNER, and NICHOLAS CHRISTIE-BLICK, Lamont-Doherty Geological Observatory of Columbia University, Palisades, NY, and JOHN R. HOGG, Petro-Canada Resources, Calgary, Alberta, Canada

Using multichannel seismic reflection and exploratory well data we examined the link between the structural and stratigraphic evolution of the Jeanne d'Arc Basin, offshore Newfoundland, and the formation of the Hibernia and Flying Foam structures. These structures are inferred to be a consequence of north-northeast-oriented compression across an intrabasinal transfer zone during late Albian time. Hydrocarbon charging of the Eastern Shoals, Avalon, and Ben Nevis formations during the early Tertiary is thought to have taken advantage of these structural culminations. Our interpretation is based on the following observations: (1) The Murre and Mercury border faults form the western boundary of the Jeanne d'Arc Basin. They are curvilinear, strike north-northeast, and are segmented by tran fer zones. In map view, each border fault segment is "spoon-shaped" and the intersection of the faults defines a triangular ridge of relatively unextended crust with an east-southeast plunge. (2) A late Barremian unconformity is regionally developed across the Grand Banks. The divergence of seismic reflectors above the unconformity attests to differential subsidence. Thus, the unconformity records an episode of rifting and block rotation. Sediment overlying the late Barremian unconformity does not onlap the Hibernia structural high, but does onlap the Central Ridge high towards the southeast. Therefore, the uplift of the Hibernia structure must have occurred after deposition of these sediments. (3) The cessation of rifting was marked by the generation of a late Albian unconformity. Erosi nal truncation associated with this surface is best developed along the western portion of the transfer zone (Nautilus transfer zone) near the Hibernia and Flying Foam structures. This erosional truncation records the reactivation and inversion of crustal blocks across the transfer zones. Orientation of the late Albian in-plane compression was north-northeast along the strike of the Jeanne d'Arc Basin. (4) Mesoscale fault patterns observed in exploratory well cores corroborate the inferred change in the state of stress from extension to compression in the late Albian determined from seismic reflection data. Syn- and post-depositional high-angle faults are observed within Barremian, Aptian, and Albian sediments of the Eastern Shoals, Avalon, and Ben Nevis formations of the Hibernia struct re. In particular, a multiphased episode of syndepositional normal faulting was terminated by a phase of reverse faulting with the orientation of the compression being approximately orthogonal to that of the extensional system.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)