Geophysical Basement Map for Yukon Flats Hydrocarbon Potential

USGS analysis presents a composite spectral map for characterizing the pre-Cenozoic basement beneath Alaska's Yukon Flats basin. The map integrates reduced-to-the-pole magnetics, magnetic potential, and basement gravity data to infer lithology and structure across the 46,000 km² basin. This dataset supports assessment of undiscovered hydrocarbon resources for remote Alaskan communities.

Use Cases

• Identify lithological domains like the Devonian to Jurassic oceanic rocks (JDat) using patterns in the red-green-blue composite spectral map.
• Assess structural hypotheses, such as overthrust plays involving Cenozoic sediments and the Schwatka sequence, by analyzing magnetic and gravity feature contrasts.
• Delineate the subsurface extent of the JDat terrane signature northward from the Tintina fault system using magnetic potential (green) and basement gravity (blue) data.
• Evaluate the potential for hydrocarbon source rocks by correlating geophysical signatures of low-grade metamorphic oceanic rocks with inferred low generation potential.
• Map basement structure obscured by vegetation and surficial deposits by interpreting domains with common geophysical characteristics from the composite image.

Strengths

• Covers a 46,000 square kilometer basin area in interior Alaska.
• Integrates three distinct geophysical data layers: reduced-to-the-pole magnetics, magnetic potential, and basement gravity.
• Analysis provides specific lithological and structural inferences, such as the identification of JDat oceanic rocks.

Limitations

• Direct validation is limited as no deep boreholes have been drilled in the basin.
• Bedrock geology is obscured by vegetation and surficial deposits, introducing interpretation uncertainty.
• The western edge of the key JDat signature is difficult to distinguish due to interfering magnetic granites.

Provenance

Source

CEOS_EXTRA, with summary provided by the USGS.

Collection Method

Analysis of regional potential field data (aeromagnetics and gravity) compiled into a composite spectral map.

Geography

Yukon Flats basin, Alaska, USA.