Geologic map of the Racetrack Basin area, central North Slope, Alaska

Description

Geologic map of the Racetrack Basin area, central North Slope, Alaska, Preliminary Interpretive Report 2025-6, presents a 1:63,360-scale interpretive bedrock geologic map of the Racetrack Basin area in the northeastern Chandler Lake quadrangle, northern Alaska. Covering approximately 675 km2 (~260 mi2), the map area includes prominent exposures of Brookian megasequence strata that record the infilling of the Colville foreland basin and the tectonic evolution of the Brooks Range. Fieldwork conducted in summer 2021 included observations at 267 localities during a helicopter-supported campaign. The resulting geologic map integrates sedimentologic, stratigraphic, and structural data to refine understanding of regional petroleum systems and basin architecture. Key outcomes of this study include recognition of previously abandoned members of the Schrader Bluff Formation and evaluation of stratigraphic thickness variability across the map area in the context of regional sequence-stratigraphic trends. The report also highlights the influence of Cretaceous depositional systems on mechanical stratigraphy and deformation, identifying paleo-shelf margins as critical transitions that affect fold geometry and distribution. This mapping effort contributes to a long-term DGGS initiative to produce a contiguous series of detailed geologic maps along the Brooks Range foothills, enhancing the geologic framework of northern Alaska. The dataset contains geologic, structural, stratigraphic, and geochronologic data organized according to the GeMS and AK GeMS mapping schemas. The complete report, geodatabase, and ESRI fonts and style files are available from the Alaska Division of Geological & Geophysical Surveys website: http://doi.org/10.14509/31723.

Resources

Name Format Description Link
Web Resource Unknown Open resource
Web Resource Unknown Open resource
Web Resource Unknown Open resource
Web Resource Unknown Open resource
geodatabase Unknown geologic map Open resource

Tags

Topics

Categories