Tectonostratigraphy of a Breached Hydrocarbon Reservoir, Sluice Brook, Western Newfoundland, Canada
Western Newfoundland has long been regarded as a petroliferous region, and one where exploration is made all the more difficult by a limited understanding of reservoir scale geology, architecture and trapping mechanisms. Under Federal and Provincial government sponsored programs, 1:50,000 mapping of this structurally complex region is beginning to provide answers.
Regional mapping north of the community of Fox Island River shows a complex pattern of westerly verging Taconic thrusts that are refolded and faulted. Coastal exposures are predominantly but not exclusively thick bedded fine-grained to granular and conglomeratic feldspathic sandstones of the Blow Me Down Brook Formation (early Cambrian). Many beds contain blackened and petroliferous smelling rocks, demonstrating for the first time the reservoir potential of Cambrian strata in this area.
One particularly extensive belt of petroliferous strata, extending for more than 500 m along the coast near Sluice Brook, appears to be the crest of a breached hydrocarbon reservoir that formed as an anticline in a refolded Taconic thrust. Development occurred in two phases. After deposition, west verging Taconic thrusting placed a hangingwall panel of Blow Me Down Brook sandstone over a footwall of thinly bedded ribbon limestones and black shales of the Cooks Brook Formation (late Cambrian). A second episode of south verging folding, with the development of a wedge thrust in Cooks Brook strata in the hinge of the anticline, generated the final form of this anticlinal trap. By recognizing this trapping style in Cambrian clastic deposits, opportunities exist for developing new prospects in this area.
New Perspectives on Exploring the Paleozoic of North America II
2005 AAPG Annual Convention (June 19-22, 2005) Technical Program