Alaska Geophysical Survey Interpretation

magnetic anomaly map of Alaska Merged magnetic anomaly map of Alaska (Connard and others, 1999, USGS Open-File Report 99-503)

Alaska is a geologic frontier with substantial mineral resource potential. Complex geology, limited outcrop, and high logistical costs make airborne geophysics essential for efficient reconnaissance. Available geophysical data for Alaska have not been fully exploited. Project objectives are to conduct systematic analysis of existing gravity, aeromagnetic and airborne electromagnetic data to map geologic trends, structural geologic and tectonic patterns, and identify key lithologies for direct integration with geologic framework and mineral potential studies.

Project activities will focus on performing an advanced analysis of the Alaska Division of Geological & Geophysical Surveys (DGGS) surveys based on USGS processing methods.


Tasks

Airborne Data Processing and Geophysical Feature Mapping

Contact: M. Andy Kass, Email: mkass@usgs.gov

The primary objective is the production of geophysical feature maps from reprocessed high-resolution airborne geophysical data that highlight physical property variations and structural features in the shallow subsurface. The workflow for this task involves systematic data quality assessment, processing, integration, and production of geologically relevant quantitative maps and cross-sections including electromagnetic inversion and complimentary magnetic interpretation. Ongoing research collaboration with the Colorado School of Mines involving the integration of magnetic data in electromagnetic inversions will be a valuable component of this task.

New Regional Aeromagnetic Map of Alaska

Contact: Rick Saltus, Email: saltus@usgs.gov

The last published magnetic data compilation for Alaska was released by the USGS in 1997. New data and advances in data compilation methods allow for significant improvement of the previous compilation. The objective of this task is to release an updated regional magnetic data compilation for Alaska. The new Alaska magnetic data compilation will use all available data, incorporate satellite magnetic data for leveling, and utilize the latest compilation methods to improve the 1997 compilation.

Geophysical Basement Maps of Alaska

Contact: Rick Saltus, Email: saltus@usgs.gov

The goal is to significantly improve the current Tertiary basin framework that dates from the Decade of North American Geology (DNAG) effort (Kirchner, 1994).


References Cited

Kirchner, C., 1994, Map showing sedimentary basins in Alaska (DNAG Alaska Volume G-1): Geological Society of America, 1 plate (scale 1:2,500,000).