Airborne geophysical maps and data released for Farewell Area
(Fairbanks, AK) – The Division of Geological & Geophysical Surveys today will release airborne geophysical survey data and maps for the complete 954-square-mile Farewell survey, which is centered about 160 miles north–northwest of Anchorage in the McGrath mining district. Data acquisition for the Farewell survey was completed in summer 2013. A small subset of the Farewell survey, the 100-square-mile Dalzell Creek area, was acquired in 2012, and these data were released in October 2013. The Dalzell Creek data have now been merged with the surrounding data from the rest of the Farewell survey. DGGS believes the data will be useful for mineral exploration, planning, and land-use management.
Miners in the McGrath mining district have produced more than 300,000 troy ounces of gold since recordkeeping began in 1880. Much of the area is covered by surficial deposits and vegetation, and has not been explored thoroughly. Airborne geophysics is a valuable tool for characterizing bedrock types, projecting geology between sparse outcrops, and for identifying vegetation-covered anomalous geologic signatures that might be associated with lode mineralization. The Farewell survey area contains prospects that represent several different mineral deposit types, including polymetallic veins, epithermal veins, porphyry copper–gold deposits, and platinum-group elements. Rare-earth-element-bearing minerals are also present in some of the granitic rocks.
Funding for the surveys was provided by the Alaska Legislature as part of a Strategic and Critical Mineral Capital Improvement Project, and the division’s Airborne Geophysical/Geological Mineral Inventory (AGGMI) program. CIRI, an Anchorage-based regional Native corporation, funded data collection and processing over the portion of the survey covering CIRI-owned lands. Data for the survey were collected and processed in 2012, 2013, and 2014 by Fugro Airborne Surveys and CGG, which acquired Fugro in 2013.
The aeromagnetic, electromagnetic, and radiometric geophysical survey data will be released today at 2 p.m. They will be available at the DGGS office in Fairbanks in DVD and paper formats, and digital files of the data and maps will be available from the division’s website at www.dggs.alaska.gov at no charge. The data and maps can be found through links on the order forms on the website. Electromagnetic-anomaly maps and an interpretive project report will be available at a later date.
DVDs and the individual map sheets are available for the cost of reproduction. They can be inspected and purchased at the division’s office at 3354 College Road, Fairbanks, Alaska 99709-3707. Call 907-451-5020 to place phone orders. Mail orders should be sent to the Fairbanks DGGS office at the above address or via fax (907-451-5050) or e-mail (firstname.lastname@example.org). Location maps and order forms are available on the DGGS website:
Farewell order form: http://www.dggs.alaska.gov/pubs/project-orderform/1006
Online link to download data: http://www.dggs.alaska.gov/pubs/id/27291
These materials also will be available for inspection by July 21, 2014, at the Alaska Resources Library and Information Services (ARLIS) at 3211 Providence Drive, Anchorage, AK 99508 (907-272-7547), and at the Historical Collection of the Alaska State Library in the State Office Building in Juneau (open 1 to 5 p.m. Monday through Friday; 907-465-2927).