Tectonostratigraphy, Sequence Stratigraphy, Sedimentology and Petroleum Geology of the Carboniferous Stoddart Group, Western Canada Sedimentary Basin, west-central Alberta, Canada
Creators: name: Yousuf, Abu
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Geology
subject: FOS: Earth and related environmental sciences
subject: Tectonostratigraphy
subject: Sequence Stratigraphy
subject: Rift Basin
subject: Sedimentology
subject: Petroleum Geology

description: Carboniferous Stoddart Group mixed siliciclastic and carbonate rocks were deposited in a tectonically active extensional setting within the Peace River Embayment, Western Canada Sedimentary Basin (WCSB). Timing and style of the tectonostratigraphic evolution of Stoddart Group depositional basin is in agreement with recently studied late Paleozoic sedimentary deposits elsewhere along the western margin of Pangea. Although origin of the tectonic stress along the western margin of the late Paleozoic WCSB is poorly understood, detailed analysis of the relative mode (e.g., vertical or rotational), rate and timing of fault block movements using relatively easily identifiable Maximum Flooding Intervals (MFI) allowed delineation of three discrete basin evolution stages (proto-rift, syn-rift and post-rift) and related tectonostratigraphic units that encompass opening and closing of the extensional Stoddart Group depositional basin. Initiation of the proto-rift stage led to Golata Formation marine mudstone deposition that was followed by a proto-rift unconformity characterized by uplift and pedogenesis. Syn-rift stage sedimentation was dominated by progradational Kiskatinaw Formation siliciclastics. Post-rift stage carbonate-dominated Taylor Flat Formation deposition ultimately terminated due to high subsidence accompanied by counter clock-wise (i.e., towards basin axis) fault block rotation and basin margin erosion. The post-rift unconformity, a basin-wide major angular unconformity, partially or completely removed Stoddart Group deposits from uplifted fault blocks and basin margin areas resulting in stratigraphic and facies belt discontinuities. Four Transgressive-Regressive sequences, linked to discrete tectonic stages, can be identified using five identifiable MFIs. Volumetrically, the bulk of Stoddart Group deposits falls within major regressive packages. Major progradations, punctuated by rapid MFIs, were triggered by major tectonic readjustments (fault block uplift / tilting) along basin margin areas that experienced waning storage and accommodation. Identification of these sequences will enhance facies predictability. Facies associations interpreted within a meaningful stratigraphic context, dominance of terrestrial palynomorph and lack of abundance of strong tidal influence suggest dominance of regressive deposits. A tectonostratigraphic Wheeler diagram for the Stoddart Group and the Ksituan carbonate allows comparison to contemporaneous and similarly styled tectonic events elsewhere along the western margin of late Paleozoic Pangea. Analysis of the Kiskatinaw Formation hydrocarbon distribution incorporates tectonostratigraphy, sequence stratigraphy, sedimentology and diagenesis.