{"action":"create","ckan_id":null,"date_created":"Sat, 28 Mar 2026 21:11:09 GMT","date_finished":null,"harvest_job_id":"c87df6d4-55a4-4157-8f97-1f84fe294e8c","harvest_source_id":"31f41541-38a0-400b-b240-10ebcb0acd9a","id":"0389cbdb-85dc-46a8-a0a3-5aeb2f8c793f","identifier":"https://dggs.alaska.gov/webpubs/metadata/RDF2017-7-u-pb.xml","parent_identifier":null,"source_hash":"8f12833bdc5ecbe38da8d99a5b50f09ac1bfa59a34a3fdbf9991231855eab1f3","source_raw":"\n\n\n\n\nGillis, R.J.\nBenowitz, J.A.\nO'Sullivan, P.B.\nLayer, P.W.\nWartes, M.A.\n2017\nZircon U-Pb and 40Ar/39Ar results from dikes collected within the Bruin Bay fault zone, lower Cook Inlet\nreport and digital data\n\nRaw Data File\nRDF 2017-7\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\n13 p.\nhttp://doi.org/10.14509/29750\n\n\n\nThis data release presents zircon U-Pb LA-ICP-MS geochronology from igneous rocks exposed in a coastal exposure at Ursus Head, Iliamna C-2 Quadrangle. Sills and dikes exposed in a coastal exposure at Ursus Head are deformed within the Bruin Bay fault zone. Common dikes intruding late Triassic Kamishak Formation strata composing the hanging-wall of the Bruin Bay fault are cut by numerous small-scale, low-angle, bedding-parallel, and high angle contractional faults. Sample 09MAW006A collected from one of many dikes deformed in the fault zone produced a uni-modal distribution of zircon ages of with a weighted mean of 206.92 +/-0.96 (2 sigma, n=47) and an MSWD of 1.1. Sample 09BG020C collected from a sill of more mafic composition yielded few zircons and produced only eight ages with a weighted mean of 212.49 +/-2.28 (2 sigma) and an MSWD of 3.42. The accompanying report also presents 40Ar/39Ar geochronology results from rocks collected roughly 7 km southwest of Contact Point, Iliamna B-3 Quadrangle.\nThe Energy Resources Group from the Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted topical stratigraphic, structural, and geochronologic studies along the western margin of lower Cook Inlet basin since 2009 to improve knowledge of its Mesozoic geologic framework and help spur industry interest in this under-explored region of the petroleum basin. The publicly-available geological and geochronologic data augment state- and federally-funded geologic mapping along the basin margin performed since 2013. This report presents zircon U-Pb LA-ICP-MS and 40Ar/39Ar step-heating geochronology results for one mafic and two felsic dikes in the Iliamna B-3 and C-2 quadrangles at Ursus Head and near Contact Point, lower Cook Inlet.\n\n>geochron-data: Geochronology lab files and applicable documentation. \n>geochron-summary: Identification numbers, coordinates, sample descriptions, and summary ages of each sample.\n\n\n\n\n\n2012\n2017\n\n\nground condition\n\n\ncomplete\nNone planned\n\n\n\n-153.618730\n-153.608320\n59.553710\n59.553160\n\n\n\n\nISO 19115 Topic Category\ngeoscientificInformation\n\n\nAlaska Division of Geological & Geophysical Surveys\n40Ar/39Ar\nAge Dates\nAnalyses\nAnalyses and Sampling\nAnalytical Lab Results\nAnalytical Results\nAr-Ar\nBedrock\nBedrock Geology\nFault Displacement\nGeochronology\nGeologic\nGeology\nIgneous\nIsotopes\nLab Methods\nLead\nMethods\nPlagioclase\nRocks\nSample Location\nStratigraphy\nStructural Geology\nStructure\nTectonics\nU-Pb\nUranium\nVolcanic\nVolcanic Rocks\nZircon\n\n\nAlaska Division of Geological & Geophysical Surveys\nContact Point\nCook Inlet\nCook Inlet Basin\nIliamna Quadrangle\nNaknek\nUrsus Head\n\n\nAlaska Division of Geological & Geophysical Surveys\nBruin Bay Fault\n\n\nWalker, J.D., Geissman, J.W., Bowring, S.A, and Babcock, L.E., comp., 2012, Geologic Time Scale v. 4.0: Geological Society of America\nCenozoic\nEocene\nMesozoic\nOligocene\nTriassic\n\n\nThis 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).\nAny 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.\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\nMetadata Manager\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5039\n(907)451-5050\ndggspubs@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\n\n\nLower Cook Inlet field studies in 2009 and 2012 were funded by the State of Alaska. We appreciate Pathfinder Aviation and pilot Merlin (Spanky) Handley for the helicopter support, Jack Barber at Alaska Air Taxi and Jose de Creeft at Northwind Aviation for charter fixed wing services, James and Shelia Isaak at Alaska Homestead Lodge, and Ray and Linda Williams at their lodge at Pile Bay for accommodations while performing field work. Lastly, we wish to thank Bob Swenson for drawing our attention to these spectacular outcrops, and who spent many hours pondering their significance.\n\n\nBetka, P.M.\nGillis, R.J.\n2014\nPreliminary characterization of brittle deformation on the Iniskin Peninsula: Implications for the kinematic history of the Bruin Bay fault system, lower Cook Inlet, Alaska\n\nPreliminary Interpretive Report\nPIR 2014-5\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\n14 p\nhttp://doi.org/10.14509/29130\n\n\n\n\nBetka, P.M.\nGillis, R.J.\n2015\nThe superposition of strike-slip and reverse-slip faults in the Bruin Bay fault system, Ursus Head, lower Cook Inlet\n\nPreliminary Interpretive Report\nPIR 2015-5-2\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\np. 5-8\nhttp://doi.org/10.14509/29457\n\n\n\n\nBetka, P.M.\nGillis, R.J.\n2016\nObservations on the Bruin Bay fault system between Chinitna and Tuxedni bays, Cook Inlet, Alaska\n\nPreliminary Interpretive Report\nPIR 2016-1-10\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\np. 73-78\nhttp://doi.org/10.14509/29544\n\n\n\n\nGillis, R.J.\nWartes, M.A.\nO'Sullivan, P.B.\n2011\nPreliminary findings from reconnaissance structural studies along the Bruin Bay fault system and adjacent areas, south-central Alaska: AAPG Pacific Section Meeting, Anchorage, Alaska, May 10, 2011\n\nPoster and Presentation\nGillis, R.J. and others, 2011\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\n1 sheet\nhttp://doi.org/10.14509/23403\n\n\n\n\nGillis, R.J.\nSwenson, R.F.\nWartes, M.A.\nFrohman, R.A.\n2013\nReconnaissance investigations of the Bruin Bay fault system along the western margin of lower Cook Inlet and upper Alaska Peninsula\n\nPreliminary Interpretive Report\nPIR 2013-1G\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\np. 33-37\nhttp://doi.org/10.14509/24850\n\n\n\n\n\nThis data set is being released in the DGGS Raw Data File series. The information has been examined by several geologists familiar with the study area, but the data and accompanying report have not been formally reviewed for technical content or for conformity to the editorial standards of DGGS. Questions regarding the accuracy of the analytical values can be best answered by the originating lab.\n\nnot applicable\nThis data release is complete.\n\n\nSample location coordinates (in NAD27 datum) were obtained using Garmin eTrex GPS units, with typical reported accuracy of about 9 ft.\n\n\n\n\nFieldwork - Samples of igneous dikes from deformed outcrops were collected by DGGS field geologists based on their cross-cutting relationships with structural features.\n2012\n\n\nData analysis - Zircon grains were isolated and prepared for Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) analysis using standard procedures combined with specific customized procedures described in: Donelick, R.A, O'Sullivan, P.B., and Ketcham, R.A., 2005, Apatite fission-track analysis: Reviews in Mineralogy and Geochemistry, Mineralogical Society of America, v. 58, p. 49-94. Significant additional discussion of analytical procedures can be found in the accompanying report.\n2012\n\n\n\n\npoint\n\n\n\n\n0.000001\n0.000001\ndecimal degrees\n\n\nNorth American Datum of 1927\nClarke 1866\n6378206.40000000037\n294.978698199999997\n\n\n\n\n\n\nrdf2017-7-geochron-data\nGeochronology lab files and applicable documentation.\nAlaska Division of Geological & Geophysical Surveys (DGGS)\ngeochron-data\n\n\n\n\nrdf2017-7-geochron-summary\nIdentification numbers, coordinates, sample descriptions, and summary ages of each sample.\nAlaska Division of Geological & Geophysical Surveys (DGGS)\ngeochron-summary\n\n\nSAMPLE\nLabel assigned in the field to identify the sample.\nAlaska Division of Geological & Geophysical Surveys\n\nGeneric example of a sample identifier: YYAAA9999X: YY= two digits of year, AAA=geologist's initials (one to three characters), 999=unique station number, X= optional alpha character which indicates that multiple samples were collected at a given location or that multiple observations were recorded in the project database.\n\n\n\nLAB_SAMPLE_NUMBER\nLabel used by the lab to identify the sample.\nAlaska Division of Geological & Geophysical Surveys and Apatite to Zircon, Inc. (A2Z)\n\nfree text\n\n\n\nLATITUDE\nLatitude, NAD27\nAlaska Division of Geological & Geophysical Surveys\n\n\n59.55316\n59.55371\ndecimal degrees\n\n\n\n\nLONGITUDE\nLongitude, NAD27\nAlaska Division of Geological & Geophysical Surveys\n\n\n-153.61873\n-153.60832\ndecimal degrees\n\n\n\n\nDESCRIPTION\nDescription of the sample\nAlaska Division of Geological & Geophysical Surveys\n\nA brief sample and/or station description.\n\n\n\nNUM_MEASUREMENTS_USED\nNumber of measurements used for calculating the age.\nApatite to Zircon, Inc. (A2Z)\n\n\n8\n47\n\n\n\n\nTOTAL_MEASUREMENTS\nTotal number of measurements.\nApatite to Zircon, Inc. (A2Z)\n\n\n36\n49\n\n\n\n\nWMEAN_AGE_MA\nWeighted mean age, in millions of years (Ma).\nApatite to Zircon, Inc. (A2Z)\n\n\n206.92\n212.49\nMa\n\n\n\n\nMEAN_AGE_MA\nMean age, in millions of years (Ma).\nApatite to Zircon, Inc. (A2Z)\n\n\n207.14\n213.54\nMa\n\n\n\n\nS2_FFER\n2-sigma error + fractionation-factor error\nApatite to Zircon, Inc. (A2Z)\n\n\n9.24\n9.61\n\n\n\n\nS2_STDEV_FFER\n2-sigma standard deviation on the 2-sigma error + fractionation-factor error\nApatite to Zircon, Inc. (A2Z)\n\n\n7.15\n11.46\n\n\n\n\nS2\n2-sigma error (not including fractionation factor error)\nApatite to Zircon, Inc. (A2Z)\n\n\n0.96\n2.28\n\n\n\n\nS2_STDEV\n2-sigma standard deviation on the 2-sigma error (not including fractionation factor error)\nApatite to Zircon, Inc. (A2Z)\n\n\n1.04\n4.05\n\n\n\n\nMSWDW\nMean Square of Weighted Deviates. Lower value indicates decreasing scatter in the data. This is, roughly, a measure of the ratio of the observed scatter of the points (from the best-fit line) to the expected scatter (from the assigned errors and error correlations). The MSWD parameter cannot be compared to the classical R2 parameter, and is not a measure of how highly correlated the X- and Y-values are. If the assigned errors are the only cause of scatter, the MSWD will tend to be near unity. MSWD values much greater than unity generally indicate either underestimated analytical errors, or the presence of non-analytical scatter. MSWD values much less than unity generally indicate either overestimated analytical errors or unrecognized error-correlations.\nApatite to Zircon, Inc. (A2Z)\n\n\n1.10\n3.42\n\n\n\n\nP_MSWDW\nStatistical scatter in the MSWD - values range between 1 (good) and 0 (poor)\nApatite to Zircon, Inc. (A2Z)\n\n\n0.003261\n1.000000\n\n\n\n\nMEAN_U_PPM\nMean concentration of uranium (U), in parts per million (ppm).\nApatite to Zircon, Inc. (A2Z)\n\n\n340.37\n1157.97\n\n\n\n\nMEAN_TH_PPM\nMean concentration of thorium (Th), in parts per million (ppm).\nApatite to Zircon, Inc. (A2Z)\n\n\n257.01\n518.99\n\n\n\n\nMEAN_U_TH_RATIO_PPM\nMean concentration of uranium (U) divided by the mean concentration of thorium (Th); in parts per million (ppm).\nApatite to Zircon, Inc. (A2Z)\n\n\n1.324\n2.231\n\n\n\n\n\n\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\nMetadata Manager\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5039\n(907)451-5050\ndggspubs@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\n\n\nRDF 2017-7\nThe 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.\n\nDGGS 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.\nContact DGGS for current pricing\n\n\n\n\nASCII tabular files\n\n\n\n\n\nhttp://doi.org/10.14509/29750\n\n\n\n\n\nFree download\n\n\n\n20170830\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\nMetadata Manager\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5039\n(907)451-5050\ndggspubs@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\n\n\nFGDC Content Standard for Digital Geospatial Metadata\nFGDC-STD-001-1998\nIf 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.\n\nhttp://www.dggs.alaska.gov/metadata/dggs.ext\ndggs metadata extensions\n\n\n\n","source_transform":null,"status":"error"}