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

Available Data Metadata Overview
File Name Data File Format Download File Size
fortymile-geophys-vector-data Vector data Download 507.3 M
fortymile-geophys-maps-prn Plot files Download 133.7 M
fortymile-geophys-geosoft-database Line data Geosoft format database Download 165.6 M
fortymile-geophys-grids-geosoft Gridded data Geosoft format Download 79.2 M
fortymile-geophys-grids-ermapper Gridded data ER Mapper Download 180.5 M
fortymile-geophys-kmz Google Earth files Download 2.0 M
fortymile-geophys-images Georeferenced raster files Download 91.6 M
fortymile-geophys-all Geophysics data compilation Download 2.4 G
fortymile-geophys-ascii-data ASCII tabular files Download 824.4 M
fortymile-geophys-documents Adobe PDF files Download 417.6 M
fortymile-geophys-maps-pdf Adobe PDF files Download 18.4 M

Publications

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Geophysics

  • GPR 2015-4. Fortymile mining district electromagnetic and magnetic airborne geophysical survey, data compilation. This publication consolidates and updates the data, grids, vectors, EM anomalies, project report and interpretation, and most of the maps published in 1999 by DGGS. New analytic signal and calculated first vertical derivative (1VD) grids have been added to this publication. This publication incorporates and consolidates material from MP 35 and MP36; PDFs 99-1 through 99-10A through G; and RIs 99-1 through 99-3. The prior publications were authored by L.E. Burns, Geoterrex-Dighem, Stevens Exploration Management Corp, R.A. Pritchard, S.A. Liss, and DGGS Staff.
  • RI 99-1. Total field magnetics of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles. Topography included; Full color, 400 dpi.
  • RI 99-3. 7200 Hz coplanar resistivity of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles. Topography included; Full color, 400 dpi.
  • 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. All of the data for this publication is included in PDF 99-9; please order PDF 99-9 instead.
  • PDF 99-1. Flight lines of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles. Blueline; topography included.
  • PDF 99-2. Total field magnetics and electromagnetic anomalies of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles. Blueline; magnetic contours and section lines included.
  • 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). Magnetic contours and topography included.
  • PDF 99-4. 900 Hz coplanar resistivity of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles. Blueline; resistivity contours and section lines included.
  • PDF 99-5. 7200 Hz coplanar resistivity of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles. Blueline; resistivity contours and section lines included.
  • PDF 99-6. Portfolio of aeromagnetic and resistivity maps of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles. Includes color and shadow maps. Maps fit 8 1/2" x 11" sheet.
  • 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. Data available on DVD only.
  • 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). Blueline.
  • 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). Blueline.
  • 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). Blueline.
  • 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). Blueline.
  • 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). Blueline.
  • 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). Blueline.
  • 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). Blueline.
  • MP 35. Color scheme variations of the total field magnetics for part of the Fortymile mining district. Full color, 400 dpi.
  • MP 36. Different coplanar resistivities and color schemes for part of the Fortymile mining district. Full color, 400 dpi.
  • RI 99-2. 900 Hz coplanar resistivity of part of the Fortymile mining district, Alaska, southern Eagle and northern Tanacross quadrangles. Topography included; Full color, 400 dpi.