Publication Date:
2011-08-01
Description:
Upper Jurassic to Lower Cretaceous synrift sandstones from two industry exploratory wells in the Flemish Pass Basin were studied for provenance using heavy mineral proxies. These sandstones were deposited during the North Atlantic rifting stage, at which time rifting intensified between Iberia and the Grand Banks. Several heavy mineral methods were used, including in-situ U-Pb geochronology and morphological and chemical analysis of detrital zircons, chemical discrimination of detrital tourmalines, and heavy mineral ratios. Clastic bed-load material entering the northern Flemish Pass Basin during the Tithonian to Berriasian was connected to transport systems reaching west, as far as 400 to 500 km (249–311 mi). Source areas to the west included igneous rocks and associated cover sequences of the Avalon zone, as well as the magmatic rocks, metasedimentary rocks, and associated cover sequences present in the Central mobile belt. The eastward-directed input of bed-load material into the basin is considered to have resulted in the concentration of sandstone units along its western margin, with deteriorating reservoir grade toward the east. Given the regional extent of drainage systems, it is likely that similar constraints apply to equivalent sandstones in the adjacent East Orphan Basin. By the Valanginian–Barremian, paleodrainage orientations had switched and bed-load material began to enter the Flemish Pass Basin from more proximal areas to the southeast with the Avalon zone basement. Overall, no evidence exists to support sediment sourcing from the Iberian margin or the Flemish Cap-Galicia Bank continental fragment to the east, and material from these areas is instead interpreted to have been shed into the incipient Atlantic Ocean or Bay of Biscay. Also, no evidence exists to support sourcing from Grenville basement farther to the west, implying that a drainage divide may have existed somewhere between central and western Newfoundland, west of which material was presumably being transported to the south or southwest. David Lowe completed his B.Sc. degree at Acadia University and M.Sc. degree in geology at Memorial University. After earning his B.Sc. degree, Lowe took on work terms with Petro-Canada, the Ontario Geological Survey, the Newfoundland and Labrador Geological Survey, and the Creait laboratory network at Memorial University. He is currently working toward his Ph.D. in geology at the University of Ottawa, where he is researching the stratal evolution of the Lower Paleozoic Potsdam Group in Ontario, Quebec, and New York. Paul Sylvester has been a professor of geochemistry at Memorial University in Newfoundland since 1998. His current research interests are on the application of automated mineralogy and in-situ geochemical analyses of heavy minerals to sedimentary provenance and stratigraphy. His work has particular potential for understanding paleodrainage patterns in frontier exploration basins where well control is sparse. Michael Enachescu obtained his Ph.D. in geosciences from the University of Bucharest, Romania. He has worked for the past 40 yr as a researcher, professional explorationist in the oil business, geoscience consultant, and teacher. Enachescu is a renowned authority on the geology of the Canadian East Coast and Arctic frontier basins, including the areas offshore Newfoundland and Labrador. Enachescu started his career in resource exploration and geophysical research in Romania, where he worked for the Prospectiuni S. A., Geological Survey of Romania and Geophysical Observatory of the Academy of Science. Since 1981, he has worked in Calgary, Houston, St John's, and Halifax on major offshore exploration programs for Suncor Resources, Trillium/Mosbacher, Husky Energy, and MGM Energy. While at Husky Energy, Enachescu was a member of the discovery and delineation teams and then a contributor to the Development Plan Applications for Terra Nova, White Rose, and Amauligak fields. In 2003–2007, he was the Husky Energy senior fellow in exploration geophysics at Memorial University of Newfoundland and an associate professor at the Department of Earth Sciences. From 2004 on, Enachescu has acted as an exploration adviser to the Government of Newfoundland, Department of Natural Resources, and to many Canadian and International scientific (Lithoprobe, Ocean Drilling Program, Integrated Oceanic Drilling Program, Marcus Langseth Science Oversight Committee, etc.) and professional committees and volunteered with several international geoscience organizations. Since 2008, Enachescu has practiced as a chief geophysicist for MGM Energy, a successful company active in the Canadian Arctic. Enachescu has also consulted for companies such as Encana, Repsol, Statoil, Geological Survey of Ireland, and a series of small exploration and investment companies. He is a registered geophysicist in Alberta and a registered geoscientist in Newfoundland and Labrador and Northwest territories, and a member of AAPG, Canadian Society of Petroleum Geologists, Society of Exploration Geophysicists, Canadian Society of Economic Geophysicists, Canadian Geophysical Union, and European Association of Geoscientists and Engineers.
Print ISSN:
0149-1423
Electronic ISSN:
1943-2674
Topics:
Geosciences
Permalink