Burns, L.E. Graham, G.R.C. Barefoot, J.D. Naibert, T.J. Fugro Airborne Surveys Corp. 2019 digital data Geophysical Report GPR 2019-15 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 15 p http://doi.org/10.14509/30222 The Iditarod electromagnetic and magnetic airborne geophysical survey is located in the Iditarod, Innoko and McGrath mining districts, about 500 km southwest from Fairbanks, Alaska. The survey is adjacent to the Aniak, Beaver Creek, and Southern Dishna River geophysical surveys. Frequency domain electromagnetic and magnetic data were collected with the DIGHEMV system from August to September 2010. A total of 6,223.8 line kilometers were collected covering 2,244.5 square kilometers. Line spacing was 400 meters (m). Data were collected 30 m above the ground surface from a helicopter towed sensor platform ('bird') on a 30 m long line. The survey was conducted by Fugro Airborne Surveys Corp. and administered by the Alaska Geological & Geophysical Surveys (DGGS). The data, as well as additional metadata, are available from the DGGS website: http://doi.org/10.14509/30222. 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 purpose of the survey was to map the magnetic and conductive properties of the survey area. Whereas the Iditarod, Innoko and McGrath mining districts have a history of placer mining, the discovery of the Donlin Gold lode deposit has kept exploration activity high in the region. Active polymetallic prospects in the survey area are Cirque and Tolstoi. Other gold and base-metal anomalies, altered zones, favorable lithologies, and structural zones are known to exist throughout the survey area. >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 2010 2019 ground condition complete None planned -158.019336 -156.203212 63.168888 62.437640 ISO 19115 Topic Category geoscientificInformation Alaska Division of Geological & Geophysical Surveys Aeromagnetic Aeromagnetic Data Aeromagnetic Map Aeromagnetic Survey Airborne Geophysical Survey Analytic Signal Apparent Resistivity Data Apparent Resistivity Map Apparent Resistivity Survey Conductivity Survey Electromagnetic Data Electromagnetic Survey Exploration First Vertical Derivative Frequency Domain Electromagnetic Data Geologic Geology Geophysical Map Geophysical Survey Geophysics Geophysics Search Tag Gridded Data Line Data Magnetic Data Magnetic Survey Magnetics Remote Sensing Resistivity Resistivity Survey Alaska Division of Geological & Geophysical Surveys Anvil Creek Beaver Mountains Black Pass California Creek Camelback Mountain Crater Mountain Deadwood Creek Dishna River Dodge Creek Ester Creek Fourth of July Creek French Joe Mountain Ganes Creek George River Granite Creek Iditarod Mining District Innoko Mining District Innoko River Lincoln Creek Malamute Gulch Maybe Creek McGrath Mining District Moore City Moore Creek Ophir Creek Potosi Creek Spruce Creek Tamarack Creek Tolstoi Creek Tolstoi Lake Victor Creek Willow Creek Yankee Creek 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. Alaska Division of Geological & Geophysical Surveys GIS Manager mailing and physical

3354 College Rd

Fairbanks AK 99709-3707 USA 907-451-5020 dggsgis@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays Funding was provided by the Alaska State Legislature as part of the DGGS Airborne Geophysical/Geological Mineral Inventory (AGGMI) program. DGGS Staff 2014 Digital Data Series DDS 2 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys http://doi.org/10.14509/27222 DGGS Staff 2016 Digital Data Series DDS 12 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 3 p http://doi.org/10.14509/29555 Geophysical data were acquired according to the 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. Data originate from one company using the same contract specifications for all data. The originating coordinate system was retained for all publication products. This data set includes files that contain processed aeromagnetic measurements, electromagnetic measurements, altimetry measurements, and locational data for the entire survey area. 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. Not applicable Burns, L.E. Fugro Airborne Surveys Corp. Fugro GeoServices, Inc. 2011 Geophysical Report GPR 2011-2 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 39 sheets, scale 1:63,360, 1 DVD http://doi.org/10.14509/22842 63360 paper 2011 publication date Burns, L.E. and others, 2011 Data collection, processing, and delivery Data collection, processing, and delivery - The airborne geophysical data were acquired under contract with Fugro Airborne Surveys, Corp. The contractor's project report and other supporting documents are in the "documents" digital data package. They provide detailed documentation of the system specifications, data collection, processing, and delivery. Burns, L.E. and others, 2011 2010 DXF conversion and geographic referencing - Contractor provided AutoCAD DXF files were converted to an ESRI Geodatabase in ArcMap v10 using the CAD to Geodatabase tool. 2019 RGB GeoTiff creation - RGB GeoTIFF raster files of gridded data were exported using Geosoft v9 by loading each Geosoft grid onto a map and using the map export tool. 2019 GeoPDF creation - Geospatial pdf file created using the Export Map function in Geosoft Oasis Montaj v9 with all maps layers visible. 2019 Standard Boundary Polygon - The final boundary polygon was generated by loading the line data in Geosoft Oasis Montaj v9. The channel MAG was gridded using the Minimum Curvature option with the following settings: grid cell size = 25, blanking distance = 800, cells to extend beyond data = 2. The polygon file was created using Grid Outline tool with edge resolution = 1. The polygon file was exported to ESRI shapefile. 2019 Universal Transverse Mercator 4 0.999600 -159 0 500000.000000 0 coordinate pair .00000001 .00000001 Meters North American Datum of 1927 Clarke 1866 6378206.40000000037 294.978698199999997 ascii_data ASCII format line data, other ASCII data Fugro Airborne Surveys Corp. ascii_data databases_geosoft Geosoft format database of line data, other Geosoft format databases Fugro Airborne Surveys Corp. databases_geosoft documents Project and field reports, survey background information, gridded data explanations, other supporting documentation Fugro Airborne Surveys Corp. and Alaska Division of Geological & Geophysical Surveys (DGGS) documents grids_ermapper Geographically registered gridded data, ER Mapper ERS format Fugro Airborne Surveys Corp. and Alaska Division of Geological & Geophysical Surveys (DGGS) grids_ermapper 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 Fugro Airborne Surveys Corp. and Alaska Division of Geological & Geophysical Surveys (DGGS) grids_geosoft images_registered GeoTiff format images of all gridded data Alaska Division of Geological & Geophysical Surveys (DGGS) images_registered kmz Keyhole markup language (kml) kmz archive files of project data. Viewable in Google Earth and other compatible programs Alaska Division of Geological & Geophysical Surveys (DGGS) kmz maps_pdf_format Printable maps in pdf format Fugro Airborne Surveys Corp. maps_pdf_format maps_prn_format Printable maps in HPGL/2 printer file format with extension .prn Fugro Airborne Surveys Corp. maps_prn_format 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 Fugro Airborne Surveys Corp. profiles_stacked vector_data Line path, data contours, and survey boundary in ESRI shapefile (SHP) format, ESRI Geodatabase format, and/or AutoCAD dxf format Fugro Airborne Surveys Corp. and Alaska Division of Geological & Geophysical Surveys (DGGS) vector_data video_flightpath Survey flight path downward-facing video Fugro Airborne Surveys Corp. video_flightpath State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys mailing and physical

3354 College Road

Fairbanks AK 99709-3707 USA 907-451-5020 907-451-5050 dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays Please view our website (http://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible. GPR 2019-15 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 (dggspubs@alaska.gov), 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. see http://dx.doi.org/10.14509/30222 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 http://dx.doi.org/10.14509/30222 Free download 20191216 Simone Montayne mailing and physical

3354 College Road

Fairbanks AK 99709-3707 USA 907-451-5020 FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 If the user has modified this metadata file in any way, the user is obligated to describe the types of modifications the user has made. User specifically agrees not to misrepresent this metadata file, 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. http://www.dggs.alaska.gov/metadata/dggs.ext dggs metadata extensions