Burns, L.E. Barefoot, J.D. Naibert, T.J. Fugro GeoServices, Inc. 2019 digital data Geophysical Report GPR 2018-8 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 3 p. http://doi.org/10.14509/29848 This geophysical survey is located in southcentral Alaska in the Valdez Creek mining district, about 185 kilometers south of Fairbanks, Alaska and about 175 kilometers northeast of Anchorage, Alaska. Frequency domain electromagnetic and magnetic data were collected with the DIGHEMV system from June to August 2013. A total of 10,547.2 line kilometers were collected covering 3464.0 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 data, as well as additional metadata, are available from the DGGS website: http://doi.org/10.14509/29848. 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 and to detect zones of conductive mineralization. Mineralization in the survey area includes magmatic Cu-Ni-PGE mineralization hosted by Triassic-age mafic to ultramafic dikes and sills. Vein, porphyry, and skarn type mineralization occur in association with Late Cretaceous to early Tertiary intrusions in the area, including the Zackly Au-Cu skarn and Au-bearing quartz veins in the headwaters of the Valdez Creek placer mine. Additionally, epigenetic Cu mineralization occurs with Nikolai basalt throughout the region. 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 >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 2013 ground condition complete None planned -148.712417 -146.092118 63.378436 62.562225 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 Clearwater Mountains Delta River Mining District Denali Highway Healy Quadrangle Maclaren River Mount Hayes Quadrangle Susitna River Talkeetna Mountains Quadrangle Valdez Creek Mining District West Fork Maclaren River 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 Metadata Manager mailing and physical

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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 Funding was provided by the Alaska State Legislature as part of the DGGS Airborne Geophysical/Geological Mineral Inventory (AGGMI) and Strategic and Critical Minerals Assessment Capital Improvement programs. DGGS Staff 2014 Digital Data Series DDS 2 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys http://doi.org/10.14509/27222 Geoterrex-Dighem Fugro Airborne Surveys Stevens Exploration Management Corp. Pritchard, R.A. Burns, L.E. Emond, A.M. DGGS Staff 2016 Digital Data Series DDS 12 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 1 DVD http://doi.org/10.14509/29555 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. 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. These data are positioned with post-processed differential GPS. Akima, H. 1970 null v. 7, no. 4 New York, NY, USA Association for Computing Machinery null paper 1970 publication date Akima, H., 1970 Data collection, processing, and delivery Geoterrex-Dighem Fugro Airborne Surveys Stevens Exploration Management Corp. Pritchard, R.A. Burns, L.E. Emond, A.M. DGGS Staff 2016 Digital Data Series DDS 12 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 1 DVD http://doi.org/10.14509/29555 paper 2016 publication date Geoterrex-Dighem and others, 2016 Data collection, processing, and delivery Data collection, processing, and delivery - The airborne geophysical data were acquired under contract to Fugro GeoServices, Inc. 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. Akima, H., 1970 Geoterrex-Dighem and others, 2016 2013 Initial publication - A subset of the contract deliverables was published 2014 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. 2018 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 Keyhole markup language (kml) KMZ archive creation - Data were exported from Geosoft and ESRI ArcMap to kml format files and/or KMZ archives. These files were then combined and modified in Google Earth Pro to create the final KMZ file. 2019 Simulated magnetic total field - In this publication's older products and documentation the magnetic data products have been referred to as Total Field Magnetics on the maps and the 'magigrf' channel in the line data. The new term 'sim_magtf' has been created to rename and clarify that the data are not representative of the true total magnetic field as the IGRF values have been removed with a single average value added back to the entire dataset, resulting in the IGRF gradient being removed. The term simulated magnetic total field and the filename abbreviation 'sim_magtf' is now used to identify these magnetic data. 2019 Data cataloged for archival and publication - All files were renamed and placed in a standardized set of folders according to the DGGS Geophysics Data Management Manual. Where applicable and as needed data were converted to newer file formats and new files were created. Supporting documentation including but not limited to readme text files, maps, figures, survey overview report, missing data type explanations, and metadata were created. 2019 Universal Transverse Mercator 6 0.999600 -147 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 Geoservices, Inc. ascii_data databases_geosoft Geosoft format database of line data, other Geosoft format databases Fugro Geoservices, Inc. databases_geosoft documents Project and field reports, survey background information, gridded data explanations, other supporting documentation Fugro Geoservices, Inc. and Alaska Division of Geological & Geophysical Surveys (DGGS) documents grids_ermapper Geographically registered gridded data, ER Mapper ERS format Fugro Geoservices, Inc. 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 Fugro Geoservices, Inc. 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 Geoservices, Inc. maps_pdf_format maps_prn_format Printable maps in HPGL/2 printer file format with extension .prn Fugro Geoservices, Inc. 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 Geoservices, Inc. 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 Geoservices, Inc. and Alaska Division of Geological & Geophysical Surveys (DGGS) vector_data video_flightpath Survey flight path downward-facing video Fugro Geoservices, Inc. video_flightpath Alaska Division of Geological & Geophysical Surveys Metadata Manager 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 GPR 2018-8 The State of Alaska makes no expressed 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. 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. Contact DGGS for current pricing 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://doi.org/10.14509/29848 Free download 20190403 Alaska Division of Geological & Geophysical Surveys Simone Montayne Metadata Manager 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 FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 If the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the Alaska Department of Natural Resources or Division of Geological & Geophysical Surveys. http://www.dggs.alaska.gov/metadata/dggs.ext dggs metadata extensions