Applying GigaPan Robotic Photo-Panorama Technology to Enhance Facies and Architectural Analyses of the Upper Cretaceous Schrader Bluff and Prince Creek Fms at Shivugak Bluffs, North Slope of Alaska, USA

van der Kolk, Dolores A.; Flaig, Peter P.; Hasiotis, Steve; Wood, Lesli J.

Deltaic, shallow marine, and shelf facies of the Upper Cretaceous (Santonian- Maastrichtian) Schrader Bluff Formation (Fm) are exposed at Shivugak Bluffs along the Colville River on the eastern margin of the National Petroleum Reserve—Alaska. Along with the interfingering distal coastal plain deposits of the Prince Creek Fm, these units are an outcrop analogue for nearby shallow, viscous-to-heavy oil hydrocarbon reservoirs on the North Slope (e.g., Milne Point, Orion, and Polaris fields). 650 m of continuous stratigraphic section were measured through these understudied, world-class outcrops (11 km long; 90-120 m high) as part of a multiyear investigation of this high-latitude marine-to-continental transitional system. My primary objective is to document high-resolution, vertical and lateral variations in facies and stratal geometries to improve reservoir models, since the Schrader Bluff Fm contains multiple sandbodies (>25 m thick) with complex bedforms intercalated with mudstones (~40 m thick).

Due to the remote location, restricted access, subvertical cliffs, and the width of the immediately adjacent Colville River a GigaPan EPIC Pro System was used to photo-document the sedimentary structures, sedimentary architecture, and stacking pattern. GigaPan robotic panhead hardware and stitching software renders high-resolution imagery of this frontier outcrop belt and fills a gap where locations are too steep for a geologist to work. Subsequently, GigaPans provide geologists with a virtual field trip where facies and lateral facies relationships can be explored further. For example, sand, shale, and bedset geometries can be interpreted, and key stratigraphic surfaces and stacking patterns can be documented. Gigapan imagery also provides a snapshot of outcrops that are highly susceptible to rockfalls, sloughing, and seasonal water-ice erosion.

The Schrader Bluff Fm at Shivugak Bluffs preserves a shallow marine, storm-dominated succession based on the abundance and preservation of hummocky cross-stratification and reactivation surfaces relative to less abundant trough cross-bedding and symmetric "wave" ripples. Transitional environments include lagoons, delta fronts, distributary mouth bars, along with potential tidal flats and estuaries. The Prince Creek Fm preserves braided and meandering channels and associated floodplain deposits. This dataset will serve as a high-latitude model for clinoform topsets deposited during the Cretaceous greenhouse.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013