Strike-slip interpretation of basin-bounding faults of the St. Lawrence lowlands basin the Quebec City area, Canada

Journal Article · Sat May 01 00:00:00 EDT 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6331727

Shaw, B R ^[1]

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1. BHP Petroleum (Americas), Houston, TX (United States)

Traditional structural interpretations of faults identified in the autochthonous, Ordovician platform rocks of the St. Lawrence Lowlands basin of Quebec, Canada, assert that the primary sense of faulting is normal, extensional, and dip-slip in motion. Interpretation of field observations such as the offset of facies boundaries in outcrop, fault surface features, fracture patterns, and fault volume considerations lead directly to difficulties with a mobile crustal bulge model for normal faulting. Newly reprocessed seismic data and well-log correlations support this interpretation and indicate a need for a different model for the deformation of the platform margin. A left-lateral, basement-involved wrench system resolves stratigraphic discordances across fault zones, contradictions in the observed geometry of hanging-wall blocks, problems concerning timing of tectonic events, and the difficulty of using extensional deformation models in a compressional setting. This reinterpretation places the timing of the platform faulting just prior to the arrival of the Taconic thrust sheet. The lateral offset of subsurface and surface depositional facies, fault trace features, well correlations, and seismic expressions document approximately 60 km of left-lateral strike-slip motion in the St. Lawrence Lowlands basin. 30 refs., 14 figs., 1 tab.

• OSTI ID: 6331727
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 77:5; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
02 PETROLEUM
QUEBEC
GEOLOGIC FAULTS
SEDIMENTARY BASINS
GEOLOGIC MODELS
STRATA MOVEMENT
AGE ESTIMATION
CANADA
DEFORMATION
MOTION
ORDOVICIAN PERIOD
PETROLEUM GEOLOGY
ROCKS
SLIP
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
NORTH AMERICA
PALEOZOIC ERA
580000* - Geosciences
020200 - Petroleum- Reserves
Geology
& Exploration