Deformation styles at the Appalachian structural front, western Newfoundland: implications of new industry seismic reflection data

1998 ◽  
Vol 35 (11) ◽  
pp. 1288-1306 ◽  
Author(s):  
Glen S Stockmal ◽  
Art Slingsby ◽  
John WF Waldron

New seismic reflection data gathered during hydrocarbon exploration in and adjacent to the external Humber zone, western Newfoundland, have important implications for the interpretation of structural style at the Appalachian front. These new data indicate that the structural front is influenced by both thin-skinned and thick-skinned structures. Where the structural front is thin skinned, it is characterized by a triangle zone, or tectonic wedge, similar to structures observed at the southeastern margin of the Canadian Cordillera, and at other orogenic fronts. The thin-skinned tectonic wedge is overridden locally by thick-skinned thrusts, which are generally emergent but are locally blind, forming a thick-skinned tectonic wedge. Timing relationships indicate that, although initial motion occurred during the Early to Middle Ordovician Taconian orogeny, the thin-skinned allochthonous slices in western Newfoundland were not emplaced until Devonian time (the Acadian orogeny). Thick-skinned deformation, which postdates thin-skinned thrusting, probably occurred between Middle Devonian and earliest Carboniferous time.

2004 ◽  
Vol 52 (3) ◽  
pp. 215-233 ◽  
Author(s):  
Glen S. Stockmal ◽  
Art Slingsby ◽  
John W.F. Waldron

Abstract Recent hydrocarbon exploration in western Newfoundland has resulted in six new wells in the Port au Port Peninsula area. Port au Port No.1, drilled in 1994/95, penetrated the Cambro-Ordovician platform and underlying Grenville basement in the hanging wall of the southeast-dipping Round Head Thrust, terminated in the platform succession in the footwall of this basement-involved inversion structure, and discovered the Garden Hill petroleum pool. The most recent well, Shoal Point K-39, was drilled in 1999 to test a model in which the Round Head Thrust loses reverse displacement to the northeast, eventually becoming a normal fault. This model hinged on an interpretation of a seismic reflection survey acquired in 1996 in Port au Port Bay. This survey is now in the public domain. In our interpretation of these data, the Round Head Thrust is associated with another basement-involved feature, the northwest-dipping Piccadilly Bay Fault, which is mapped on Port au Port Peninsula. Active as normal faults in the Taconian foreland, both these faults were later inverted during Acadian orogenesis. The present reverse offset on the Piccadilly Bay Fault was previously interpreted as normal offset on the southeast-dipping Round Head Thrust. Our new interpretation is consistent with mapping on Port au Port Peninsula and north of Stephenville, where all basement-involved faults are inverted and display reverse senses of motion. It also explains spatially restricted, enigmatic reflections adjacent to the faults as carbonate conglomerates of the Cape Cormorant Formation or Daniel’s Harbour Member, units associated with inverted thick-skinned faults. The K-39 well, which targeted the footwall of the Round Head Thrust, actually penetrated the hanging wall of the Piccadilly Bay Fault. This distinction is important because the reservoir model invoked for this play involved preferential karstification and subsequent dolomitization in the footwalls of inverted thick-skinned faults. The apparent magnitude of structural inversion across the Piccadilly Bay Fault suggests other possible structural plays to the northeast of K-39.


2015 ◽  
Vol 55 (2) ◽  
pp. 421
Author(s):  
Paul Bellingham ◽  
Leanne Cowie ◽  
Rod Graham ◽  
Brian Horn ◽  
Kenneth McDermott ◽  
...  

The Carnarvon Basin has long been a focus for hydrocarbon exploration and development. Many models have been proposed for the basin’s lithospheric structure, although the great thickness of the Mungaroo delta system has hampered the clear imaging of the underlying rift and break-up structure. New deep, long offset seismic reflection data acquired across the basin as a part of ION’s Westralia SPAN survey provide unique imaging of the deep basement structures and the complete overlying sedimentary section. The survey crossed the offshore terrains, from weakly stretched continental crust to oceanic crust. The margin has developed during two major events; one of Permo-Carboniferous age, prior to the Mungaroo delta system, and one of Middle to Upper Jurassic age. There is a possibility that the basement terrain under parts of the Exmouth Plateau is actually Permo-Carboniferous oceanic crust, rather than hyper-extended continental crust or exhumed continental lithospheric mantle. Deformation during the second major event in the Jurassic was focussed in the Barrow-Dampier Sub-basin and at the present day ocean-continent transition with little deformation across the Exmouth Plateau in-between. The only basement involved extension appears to be in the Barrow-Dampier system and appears to be non-volcanic. The outer margin along the northwest edge of the Exmouth Plateau includes significant volcanic input, likely underplating and emplacement of seaward-dipping reflectors.


2016 ◽  
Vol 34 (2) ◽  
Author(s):  
Rodrigo Francis Revorêdo ◽  
Carlos César Nascimento da Silva

ABSTRACT. In the hydrocarbon exploration activities, the reprocessing of old seismic reflection data, acquired with few channels and with low signal-to-noise ratio, is commonly undertaken to ameliorate the quality and reliability of the seismic images...Keywords: seismic processing, velocity analysis, CVS. RESUMO. É comum na exploração de hidrocarbonetos o reprocessamento de dados sísmicos antigos, por vezes com um baixo número de canais e baixa razão sinal/ruído, com o objetivo de gerar uma imagem de melhor qualidade e confiabilidade quando comparada àquelas já existentes...Palavras-chave: processamento sísmico, análise de velocidades, CVS. 


2006 ◽  
Vol 55 (3) ◽  
pp. 129-139 ◽  
Author(s):  
Avihu Ginzburg ◽  
Moshe Reshef ◽  
Zvi Ben-Avraham ◽  
Uri Schattner

Sign in / Sign up

Export Citation Format

Share Document