Geology of the Cobblestone Creek-May Creek area, east-central Brooks Range Foothills, Alaska

Mull, C.G.Harris, E.E.Delaney, P.R.Swenson, R.F.2009Geology of the Cobblestone Creek-May Creek area, east-central Brooks Range Foothills, AlaskageodatabasePreliminary Interpretive ReportPIR 2009-5Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys40 p., 1 sheet, scale 1:63,360https://doi.org/10.14509/19661Geology of the Cobblestone Creek-May Creek area, east-central Brooks Range Foothills, Alaska, Preliminary Interpretive Report 2009-5, presents a 1:63,360 scale geologic map of the Cobblestone Creek-May Creek area of the foothills of the Endicott Mountains. This map is one of a series of areas selected for detailed mapping to document important structural and stratigraphic relationships at the east-central Brooks Range mountain front. The Cobblestone Creek-May Creek area is important in delineating the stratigraphic and structural relationships in this area because, unlike the adjacent valleys of the Itkillik and Nanushuk rivers, Cobblestone and May Creeks were not glaciated during the Pleistocene, and thus bedrock exposures are generally more continuous. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/19661.Local field studies by the Alaska Division of Geological & Geophysical Surveys (DGGS) began in the area in 1982 and continued intermittently in conjunction with other field studies. In recent years, interest in hydrocarbon exploration in the Brooks Range foothills has increased considerably, resulting in an opportunity to compile previous studies as well as to carry out additional field studies to address specific structural and stratigraphic problems. In addition, ongoing mapping and structural and stratigraphic studies in the Siksikpuk River - Tiglukpuk Creek area to the west (Peapples and others, 2007) have resulted in some revised structural and stratigraphic concepts that have proven to be applicable to the Cobblestone Creek-May Creek map area and the adjacent Kanayut River map area to the west.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/10.14509/3058420092022ground conditionIn workNone planned-150.640466-149.94858768.75955068.356982ISO 19115 Topic CategorygeoscientificInformationAlaska Division of Geological & Geophysical SurveysAllochthonAlluviumArgilliteBariteBentoniteBrecciaBuchiaChertClayClaystoneCoalColluviumConglomerateContactCoquinaDolomiteEnergy Section Maps of InterestFaultsGasGeologicGeologic MapGeologyGravelGraywackeHalobiaHydrocarbonLimestoneMarineMarlMonotisMudstoneNonmarineOlistostromePebblePelecypodsPetroleumPorosityQuartzRocksSandSandstoneShaleSideriteSiltSiltstoneSurficialTalusTectonicsTillTuffTurbiditeTurbiditesAlaska Division of Geological & Geophysical SurveysArc MountainBrooks RangeCascade CreekChandler Lake QuadrangleCobblestone CreekItkillik RiverKuhsuman CreekMay CreekNanushuk LakeNanushuk RiverNorth SlopePeregrine CreekAlaska Division of Geological & Geophysical SurveysBuchia Limestone CoquinaCobblestone MemberFortress Mountain FormationImnaitchiak ChertKayak ShaleLisburne GroupNanushuk FormationOkpikruak FormationOtuk FormationSeabee FormationSiksikpuk FormationTorok FormationTuluvak FormationUnnamed Phosphatic-Manganiferous ShaleWalker, J.D., Geissman, J.W., Bowring, S.A, and Babcock, L.E., comp., 2012, Geologic Time Scale v. 4.0: Geological Society of AmericaAlbianAptianBarremianBerriasianCenomanianConiacianCretaceousJurassicMiddle TriassicMississippianPennsylvanianPermianQuaternaryTriassicTuronianValanginianThis 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.This geologic map was funded by the State of Alaska. Geologic field investigations by: C.G. Mull (1982, 1985, 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1999, 2000, 2001); E.E. Harris (1985, 1999, 2000, 2001); Paige R. Peapples (2001); D.L. LePain, R.A. Kirkham, and R.R. Reifenstuhl (1999, 2000, 2001); Jerry Siok (1983, 1985); D.A. Bodnar (1983); K.E. Adams and M.L. Buckingham (1985); D.W. Houseknecht, C.J. Schenk, and T.J. Ryherd (2001); M.D. Myers (1989, 1999); M.T. Whalen and M.B. Mickey (2000). Digital cartography by Paige R. Delaney. This map was converted to GeMS and then finalized by Alec D. Wildland and Mike Hendricks.Dumoulin, J.A.Whalen, M.T.2015Reconnaissance investigation of the Lisburne Group in the Cobblestone Creek area, Chandler Lake Quadrangle, AlaskaPreliminary Interpretive ReportPIR 2015-2Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys18 phttps://doi.org/10.14509/29403Attribute fields within each feature class are populated using the map symbology and corresponding applicable values from the GeMS and AK GeMS specifications. When known, certainty in attribute interpretation is indicated in the relevant fields. Attribute accuracy varies throughout the map and is scale-dependent.All polygon features were topologically validated according to the AK GeMS geologic mapping schema specifications.This publication is a DGGS Preliminary Interpretive Report (PIR). A PIR provides timely release of maps and reports with a preliminary interpretation of geology or analytical data. Several scientists familiar with the geology of map area reviewed this product for general readability and logical consistency, but it has not undergone technical peer review.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.Ekberg, P.G.Hendricks, M.D.Athey, J.E.2021AK GeMS symbology: A description of the AK GeMS style fileMiscellaneous PublicationMP 169Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys7 phttps://doi.org/10.14509/30584paper2021publication dateEkberg, P.G. and others, 2021GIS analysis and digital cartographyHendricks, M.D.Ekberg, P.G.Athey, J.E.Wyatt, W.C.Willingham, A.L.Naibert, T.J.2021AK GeMS data dictionary: A description of the Alaska geologic mapping schemaMiscellaneous PublicationMP 170Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys10 phttps://doi.org/10.14509/30669paper2021publication dateHendricks, M.D. and others, 2021GIS analysis and digital cartographyU.S. Geological Survey National Cooperative Geologic Mapping Program2020GeMS (Geologic Map Schema) - A standard format for the digital publication of geologic mapsTechniques and MethodsTM 11-B10United StatesU.S. Geological Survey1 phttps://dggs.alaska.gov/pubs/id/30585paper2020publication dateU.S. Geological Survey National Cooperative Geologic Mapping Program, 2020GIS analysis and digital cartographyGeologic mapping - Geologic mapping took place during three-week field seasons during June-July 2004 and 2005. Mappers recorded observations in field notebooks and on aerial photographs and topographic maps, predominantly at 1:63,360 scale. Bedrock mapping involved using aerial photographs and topographic maps on a daily basis for checking geologic contacts and units. Stations were located using aerial photographs, topographic maps, and altimeters. In most instances, GPS devices were used. Stations were also plotted by hand on stable mylar topographic bases, and coordinates were determined by digitizing. The final map was compiled using field observations and all known geologic data from previous work in the quadrangle. Data were compiled on multiple layers of stable mylar at 1:63,360 scale and then scanned and digitized. The conceptual framework for the geology incorporates key ideas from preexisting literature with new data and interpretations developed from field mapping and analytical findings. The accompanying map provides a comprehensive bibliographic reference list of prior works used to identify and delineate rock units and structural elements.2009GIS analysis and digital cartography - This data distribution package's geologic and geographic features were organized and attributed according to the AK GeMS geologic mapping schema. The data were programmatically transformed to provide download options in three formats: (1) an AK GeMS data package that includes the complete AK GeMS database and associated files, (2) a GeMS data package that is a conversion of the AK GeMS database into the base GeMS standard published by the USGS, and (3) a shapefile data package that includes two simple shapefile representations of the data.Ekberg, P.G. and others, 2021Hendricks, M.D. and others, 2021U.S. Geological Survey National Cooperative Geologic Mapping Program, 20202022vectorUniversal Transverse Mercator50.999600-1530500000.0000000coordinate pair.00000001.00000001MetersNAD27Clarke 18666378206.4294.9786982cobblestone_ak_gems_db_pkgGeodatabase, layer files, style files, and fontsDGGScobblestone_ak_gems_db_pkgcobblestone_gems_db_pkgGeodatabase, layer files, style files, and fontsDGGScobblestone_gems_db_pkgcobblestone_gems_shapefile_pkgShapefiles and open data filesDGGScobblestone_gems_shapefile_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