Preliminary bedrock geologic map database, northeastern Richardson mining district, Alaska

Twelker, EvanWildland, A.D.Werdon, M.B.Sicard, K.R.Wypych, AlicjaNaibert, T.J.Athey, J.E.Willingham, A.L.Lockett, A.C.2021Preliminary bedrock geologic map database, northeastern Richardson mining district, AlaskageodatabaseRaw Data FileRDF 2021-9Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys4 p.https://doi.org/10.14509/30676During the 2017 field season, geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted geologic mapping and sampling of part of the Richardson mining district southeast of Fairbanks, Alaska. The project area is about 30 miles west of the Pogo gold mine and covers gold exploration activity at the Montecristo and Uncle Sam properties. This work aims to build an improved understanding of the area's geology and controls on gold mineralization for purposes of exploration targeting and mineral-resource assessment. The 260-square-mile map area lies between the Salcha River and Shaw Creek and is bounded by the Trans-Alaska Pipeline access road to the southwest. The area is characterized by forested, moderate-relief hills blanketed by vegetation, loess, and locally, sand dunes. Rock outcrop is less than one percent; consequently, the map interpretation relies heavily on the DGGS East Richardson airborne magnetic and electromagnetic survey as well as rocks collected from pits dug into rocky colluvial deposits below surficial loess or sand. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/30676.This work aims to build an improved understanding of the area's geology and controls on gold mineralization for purposes of exploration targeting and mineral-resource assessment.This geodatabase is organized according to the AK GeMS mapping schema Hendricks, M.D., Ekberg, P.G., Athey, J.E., Wyatt, W.C., Willingham, A.L., and Naibert, T.J., 2021, AK GeMS data dictionary: A description of the Alaska geologic mapping schema: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 170, 10 p. https://doi.org/10.14509/30669. The distribution package includes ESRI fonts and style files, along with usage instructions. Further documentation of the symbology is provided by Ekberg, P.G., Hendricks, M.D., and Athey, J.E., 2021, AK GeMS symbology: A description of the AK GeMS style file: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 169, 7 p. https://doi.org/10.14509/305842017ground conditioncompleteNone planned-146.376046-145.66255764.55539864.291956ISO 19115 Topic CategorygeoscientificInformationAlaska Division of Geological & Geophysical SurveysAmphiboliteBedrockBedrock GeologyDGGSDioriteEconomic GeologyEconomic StudyGeologicGeologyGneissGraniteIgneousIgneous RocksMetamorphicMetamorphic RocksMetamorphismMetasedimentary RocksMetavolcanic rocksMigmatiteMineral AssessmentMineral DepositMineral DevelopmentMineral LocalitiesMineral ProspectMineral ResourcesMineralsMiningOre DepositOresOrthogneissPegmatitePlutonicPlutonic RocksPlutonsPorphyryPrecious MetalsProspecting SitesQuartziteResource AssessmentResource InformationResourcesRock UnitsRocksSchistSerpentiniteStructureAlaska Division of Geological & Geophysical SurveysAlaskaCaribou CreekFairbanks Mining DistrictFlat CreekGilles CreekGold Run CreekKeystone CreekLenant CreekMcCoy CreekMinton CreekMonte Cristo CreekNinetyeight CreekRichardson Mining DistrictRosa CreekSalcha RiverTwentyfive Mile CreekUncle Sam CreekWalker, J.D., Geissman, J.W., Bowring, S.A, and Babcock, L.E., comp., 2012, Geologic Time Scale v. 4.0: Geological Society of AmericaCretaceousDevonianEarly CretaceousLate CretaceousMississippianProterozoicTriassicThis 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 SurveysMetadata Managermailing and physical

3354 College Road

FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysPlease view our website (https://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.We thank Dennis McDowell and Pat Smith of Great American Minerals Exploration (GAME) and Bill Cronk and Northern Empire Resources Corp. for sharing data and insights on the district. Thanks also to Richard Lessard, Rainer Newberry, and Dave Larimer for geological discussions. Sumitomo Metal Mining Pogo provided access to the Pogo mine road, and Alyeska Pipeline Service Company granted access to the pipeline right of way. This project was funded by the State of Alaska.Graham, G.E.Jozwik, Diana2007Data tables related to geology and gold mineralization in the Richardson district, east-central AlaskaRaw Data FileRDF 2007-2Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys32 phttps://doi.org/10.14509/15819Naibert, T.J.Benowitz, J.A.Wypych, AlicjaSicard, K.R.Twelker, Evan201840Ar/39Ar data from the Tanacross D-1 and D-2, Big Delta B-4 and B-5, and Mount Hayes A-6 quadrangles, AlaskaRaw Data FileRDF 2018-3Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys15 phttps://doi.org/10.14509/30112Twelker, EvanBenowitz, J.A.Naibert, T.J.202040Ar/39Ar data from the Richardson mining district, Big Delta Quadrangle, AlaskaRaw Data FileRDF 2020-11Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys10 phttps://doi.org/10.14509/30530Twelker, EvanWerdon, M.B.Sicard, K.R.Wypych, AlicjaNaibert, T.J.Athey, J.E.Willingham, A.L.Lockett, A.C.2017Geologic mapping in the Richardson-Uncle Sam area, interior Alaska (presentation): Alaska Miners Association Annual Convention, Anchorage, Alaska, November 7-12, 2017Poster and PresentationTwelker, Evan and others, 2017Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys37 phttps://doi.org/10.14509/29811Twelker, EvanWypych, AlicjaSicard, K.R.Naibert, T.J.Montayne, SimoneNewberry, R.J.Wyatt, W.C.2018Major-oxide and trace-element geochemical data from rocks collected in the Richardson mining district, Big Delta Quadrangle, AlaskaRaw Data FileRDF 2018-6Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys4 phttps://doi.org/10.14509/30119Twelker, EvanWypych, AlicjaSicard, K.R.Naibert, T.J.Werdon, M.B.Athey, J.E.Willingham, A.L.Lockett, A.C.2017Major-oxide and trace-element geochemical data from rocks collected in the Richardson mining district, Big Delta Quadrangle, AlaskaRaw Data FileRDF 2017-11Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys4 phttps://doi.org/10.14509/29779Twelker, EvanO'Sullivan, P.B.2021U-Pb zircon data and ages for bedrock samples from the Richardson mining district, Big Delta Quadrangle, AlaskaRaw Data FileRDF 2020-14Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys17 phttps://doi.org/10.14509/30555Certainty in attribute interpretation varies throughout the map and is scale dependant. Attribute fields within each feature class record the authors' degree of confidence in the existence or identity of applicable features.All polygon features were topologically validated according to specifications of the AK GeMS geologic mapping schema.This publication is released as a DGGS Raw Data File (RDF). Reports in the RDF series present field data and analytical results with limited or no interpretation by DGGS staff or project collaborators. The report and accompanying data have been evaluated by project staff for general readability and logical consistency but have not undergone technical peer review. Information presented in this release is subject to change.Certainty in feature boundaries or location varies throughout the map. Data fields within each feature class and the accompanying orientation and location confidence lookup tables record the authors' degree of confidence in the location of applicable features.Burns, L.E.Fugro Airborne Surveys Corp.Stevens Exploration Management Corp.2006Line, grid, and vector data and plot files for the airborne geophysical survey data of parts of the east Richardson, Liscum, and Black Mountain areas, interior AlaskaGeophysical ReportGPR 2006-5Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys29 sheets, 1 DVDhttps://doi.org/10.14509/14531digital2006publication dateBurns, L.E. and others, 2006Bedrock mappingHendricks, M.D.Ekberg, P.G.Athey, J.E.Wyatt, W.C.2020AK GeMS data dictionary: A description of the AK GeMS database schemaMiscellaneous PublicationMP 168Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveyshttps://doi.org/10.14509/30583digital2020publication dateHendricks, M.D. and others, 2020GIS analysis and digital cartographyNeuendorf, K.K.E.Mehl, J.P., Jr.Jackson, J.A.2011Glossary of GeologyAlexandria, VirginiaAmerican Geological Institute799 phttps://www.americangeosciences.org/pubs/glossarydigital2011publication dateNeuendorf, K.K.E. and others, 2011GIS analysis and digital cartographyU.S. Geological Survey, EROS Data Center2013IFSAR Orthorectified Radar Image (ORI) AlaskaSioux Falls, SDU.S. Geological Surveyhttps://doi.org/10.5066/F7CJ8CSFdigital2013publication dateU.S. Geological Survey, EROS Data Center, 2013GIS analysis and digital cartographyWalker, J.D.Geissman, J.W.Bowring, S.A.Babcock, L.E.2018Geologic Time Scale v. 5.0Boulder, COGeological Society of Americahttps://www.geosociety.org/documents/gsa/timescale/timescl.pdfpaper2018publication dateWalker, J.D. and others, 2018GIS analysis and digital cartographyWeber, F.R.Foster, H.L.Keith, T.E.C.Dusel-Bacon, Cynthia1978Preliminary geologic map of the Big Delta Quadrangle, AlaskaOpen-File ReportOF 78-529-AUnited StatesU.S. Geological Survey1 sheet, scale 1:250,000https://dggs.alaska.gov/pubs/id/12411250000paper1978publication dateWeber, F.R. and others, 1978Bedrock mappingBedrock mapping - During the 2017 field season, DGGS geologists conducted geologic mapping and sampling of part of the Richardson mining district southeast of Fairbanks, Alaska. Rock outcrop is less than one percent; consequently, the map interpretation relies heavily on the DGGS East Richardson airborne magnetic and electromagnetic survey as well as rocks collected from pits dug into rocky colluvial deposits below surficial loess or sand. Location data for outcrop observations were collected using GPS-enabled tablets running the ESRI Collector App. Geologic unit identificationBurns, L.E. and others, 2006Weber, F.R. and others, 19782017GIS analysis and digital cartography - The geologic and geographic features portrayed in this data distribution package were organized and attributed according to the AK GeMS geologic mapping schema.Hendricks, M.D. and others, 2020Neuendorf, K.K.E. and others, 2011U.S. Geological Survey, EROS Data Center, 2013Walker, J.D. and others, 20182021Technical review - The report and accompanying data were evaluated by project staff for general readability and logical consistency but have not undergone technical peer review.2021vectorUniversal Transverse Mercator60.999600-1470500000.0000000coordinate pair.00000001.00000001MetersNAD83GRS 806378137298.257222101000025richardson_ak_gems_db_pkgGeodatabase, layer files, style files, and fontsAlaska Division of Geological & Geophysical Surveysrichardson_ak_gems_db_pkgAlaska Division of Geological & Geophysical SurveysMetadata Managermailing and physical

3354 College Road

FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysFGDC Content Standard for Digital Geospatial MetadataFGDC-STD-001-1998If 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.https://dggs.alaska.gov/metadata/dggs.extdggs metadata extensions