Fortymile Mining District Geophysical Survey

The Fortymile electromagnetic and magnetic airborne geophysical survey data were acquired with a DIGHEM-V Electromagnetic (EM) system and a cesium magnetometer. The EM and magnetic sensors were flown at a height of 30 meters (m). In addition the survey recorded data from radar and laser altimeters, a GPS navigation system, 50/60 Hz monitors and a video camera. Flights were performed with an AS-350-B2 Squirrel helicopter at a mean terrain clearance of 60 m along N-S survey flight lines with a spacing of 400 m. Tie lines were flown perpendicular to the flight lines at intervals of approximately 4,800 m

Publications

• GPR 2015-4. Fortymile mining district electromagnetic and magnetic airborne geophysical survey data compilation.
• RI 99-1. Total field magnetics of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.
• RI 99-3. 7200 Hz coplanar resistivity of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.
• PDF 99-8. 1 CD-ROM containing gridded files and section line of 1998 geophysical survey data for part of the Fortymile and Livengood mining districts, Alaska, southern Eagle, northern Tanacross, and central Livengood quadrangles.
• PDF 99-1. Flight lines of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.
• PDF 99-2. Total field magnetics and electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.
• PDF 99-3. Total field magnetics and electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles (clear diazo film version).
• PDF 99-4. 900 Hz coplanar resistivity of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.
• PDF 99-5. 7200 Hz coplanar resistivity of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.
• PDF 99-6. Portfolio of aeromagnetic and resistivity maps of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.
• PDF 99-7. Project report of the 1998 geophysical survey data of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.
• PDF 99-9. CD-ROM containing profile and gridded data and section lines of the 1998 geophysical survey data for part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.
• PDF 99-10A. Total field magnetics and detailed electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles (western part of Eagle B-3).
• PDF 99-10B. Total field magnetics and detailed electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles (northwestern Eagle A-3, part of A-4).
• PDF 99-10C. Total field magnetics and detailed electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles (eastern Eagle A-3).
• PDF 99-10D. Total field magnetics and detailed electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles (Eagle A-2).
• PDF 99-10E. Total field magnetics and detailed electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles (Eagle A-1).
• PDF 99-10F. Total field magnetics and detailed electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles (northern Tanacross D-2).
• PDF 99-10G. Total field magnetics and detailed electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles (northern Tanacross D-1).
• MP 35. Color scheme variations of the total field magnetics for part of the Fortymile mining district.
• MP 36. Different coplanar resistivities and color schemes for part of the Fortymile mining district.
• RI 99-2. 900 Hz coplanar resistivity of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles.