ascii_data: ASCII format line data, other ASCII data databases_geosoft: Geosoft format database of line data, other Geosoft format databases documents: Project and field reports, survey background information, gridded data explanations, other supporting documentation grids_ermapper: Geographically registered gridded data, ER Mapper ERS format grids_geosoft: Geosoft-format binary grids, these grids can be viewed in ESRI ArcMap using a free plugin from Geosoft or using the free viewer available from Geosoft images_registered: GeoTiff format images of all gridded data kmz: Keyhole markup language (kml) kmz archive files of project data. Viewable in Google Earth and other compatible programs maps_pdf_format: Printable maps in pdf format maps_prn_format: Printable maps in HPGL/2 printer file format with extension .prn profiles_stacked: Distance-based profiles of the digitally recorded geophysical data are generated and plotted at an appropriate scale. The profiles display electromagnetic anomalies with their respective interpretive symbols vector_data: Line path, data contours, and survey boundary in ESRI shapefile (SHP) format, ESRI Geodatabase format, and/or AutoCAD dxf format video_flightpath: Survey flight path downward-facing video
Burns, L.E., Graham, G.R.C., Emond, A.M., and Barefoot, J.D., 2019, Farewell electromagnetic, magnetic, and radiometric airborne geophysical survey data compilation: Geophysical Report GPR 2019-12, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest .00000001
Ordinates (y-coordinates) are specified to the nearest .00000001
Planar coordinates are specified in Meters
The horizontal datum used is North American Datum of 1927.
The ellipsoid used is Clarke 1866.
The semi-major axis of the ellipsoid used is 6378206.40000000037.
The flattening of the ellipsoid used is 1/294.978698199999997.
Funding was provided by the Alaska State Legislature as part of the DGGS Airborne Geophysical/Geological Mineral Inventory (AGGMI) program, the Alaska Strategic and Critical Minerals Assessment Capital Improvement Project (SCMA), and by a contribution from Cook Inlet Region, Inc.
This airborne geophysical survey is part of a program to acquire data on Alaska's most promising mineral belts and districts. The information acquired is aimed at catalyzing new private sector exploration, discovery, and ultimate development and production. The primary goal of the Farewell project is to delineate prospective mineral zones and to support detailed geologic mapping. Many prospects are in the survey area and are thought to represent several different deposit types, including polymetallic veins, epithermal veins, and porphyry copper deposits.
Burns, L.E., CGG, and Fugro GeoServices, Inc., 2014, Farewell survey area: Airborne magnetic, electromagnetic and radiometric data in line (point), grid, vector, and map formats, McGrath and Lime Hills quadrangles, south-central Alaska: Geophysical Report GPR 2014-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
CGG, and Fugro GeoServices, Inc., 2015, Farewell and Middle Styx survey areas: Project report, interpretation maps, EM anomalies, stacked multi-channel profiles, and other products of the airborne geophysical surveys, parts of the McGrath, Lime Hills, and Tyonek quadrangles, south-central Alaska: Geophysical Report GPR 2014-4, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Data sources used in this process:
Staff, DGGS, 2014, Airborne GeophysWeb: A compilation of geophysical data from DGGS and cooperating agencies: Digital Data Series DDS 2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Geoterrex-Dighem, Surveys, Fugro Airborne, Stevens Exploration Management Corp., Pritchard, R.A., Burns, L.E., Emond, A.M., and Staff, DGGS, 2016, Sub-regional, merged, gridded airborne geophysical data: Digital Data Series DDS 12, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Geophysical data were acquired according to contractor, contract, and request-for-proposals specifications. For additional detail about survey parameters, see the accompanying project report available in the documents directory of this data distribution package.
These data are positioned with post-processed differential GPS. Discussion of grid resolution and factors that may impact the overall horizontal accuracy of the gridded data is available in the documents directory of this data distribution package.
This data set includes files that contain processed aeromagnetic measurements, electromagnetic measurements, altimetry measurements, and locational data for the entire survey area.
Data originate from one company using the same contract specifications for all data. The originating coordinate system was retained for all publication products.
Are there legal restrictions on access or use of the data?
- This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
- Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
The State of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity, whether from the use of the electronic services or products, any failure thereof, or otherwise, and in no event will the State of Alaska's liability to the requestor or anyone else exceed the fee paid for the electronic service or product.
DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (email@example.com), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.
|Data format:||DGGS geophysics datasets are typically compilations of multiple digital data file formats. These formats may include: GeoTiff, ESRI shapefile, Geosoft binary grid (GRD), Microsoft Office documents, PDF, ER Mapper ERS, ASCII text files (including CSV), Geosoft ASCII grid (GXF), Geosoft database, AutoCAD DXF, Geosoft plot file (PLT), Printer files (HPP, PRN, or other), digital images (multiple formats), digital video (multiple formats), Geosoft ASCII XYZ, Geosoft ASCII files (PLY, i0, EXP), and KMZ|