Subsurface stratigraphic picks of the Middle-Upper Triassic Shublik Formation, Alaska North Slope

• Main Authors: Rouse, William A, Whidden, Katherine J, Dumoulin, Julie A, Houseknecht, David W
• Format: Dataset
• Language: unknown
• Published: U.S. Geological Survey 2020
• Subjects: Energy Resources; Arctic; Alaska North Slope; north slope; Prudhoe Bay; Alaska
• Online Access: https://dx.doi.org/10.5066/p91o4b6r; https://www.sciencebase.gov/catalog/item/5e138050e4b0ecf25c53b38c

The Middle-Upper Triassic Shublik Formation is the main source rock for Arctic Alaska oil and gas accumulations, including the supergiant Prudhoe Bay field. A revised stratigraphic framework recently has been developed in outcrop for the Shublik and related strata that delineates three large-scale stratigraphic units: 1) the lower clastic (LC) unit, 2) the middle carbonate-chert (MCC) unit, and 3) the upper clastic-carbonate (UCC) unit. The three stratigraphic units were interpreted to comprise five transgressive-regressive (T-R) sequences (LC1, MCC1, MCC2, MCC3, and UCC1). This outcrop-based framework has been extended to the subsurface of the Alaska North Slope using gamma-ray logs from 161 exploration wells. Subsurface stratigraphic picks of the five T-R sequences within the Shublik Formation for each well are documented herein.