Identification_Information: Citation: Citation_Information: Originator: Gillis, R.J. Originator: Benowitz, J.A. Originator: O'Sullivan, P.B. Originator: Layer, P.W. Originator: Wartes, M.A. Publication_Date: 2017 Title: Zircon U-Pb and 40Ar/39Ar results from dikes collected within the Bruin Bay fault zone, lower Cook Inlet Geospatial_Data_Presentation_Form: report and digital data Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2017-7 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 13 p. Online_Linkage: http://doi.org/10.14509/29750 Description: Abstract: This 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. Purpose: The 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. Supplemental_Information: >geochron-data: Geochronology lab files and applicable documentation. >geochron-summary: Identification numbers, coordinates, sample descriptions, and summary ages of each sample. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2012 Ending_Date: 2017 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -153.618730 East_Bounding_Coordinate: -153.608320 North_Bounding_Coordinate: 59.553710 South_Bounding_Coordinate: 59.553160 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Theme_Keyword: 40Ar/39Ar Theme_Keyword: Age Dates Theme_Keyword: Analyses Theme_Keyword: Analyses and Sampling Theme_Keyword: Analytical Lab Results Theme_Keyword: Analytical Results Theme_Keyword: Ar-Ar Theme_Keyword: Bedrock Theme_Keyword: Bedrock Geology Theme_Keyword: Fault Displacement Theme_Keyword: Geochronology Theme_Keyword: Geologic Theme_Keyword: Geology Theme_Keyword: Igneous Theme_Keyword: Isotopes Theme_Keyword: Lab Methods Theme_Keyword: Lead Theme_Keyword: Methods Theme_Keyword: Plagioclase Theme_Keyword: Rocks Theme_Keyword: Sample Location Theme_Keyword: Stratigraphy Theme_Keyword: Structural Geology Theme_Keyword: Structure Theme_Keyword: Tectonics Theme_Keyword: U-Pb Theme_Keyword: Uranium Theme_Keyword: Volcanic Theme_Keyword: Volcanic Rocks Theme_Keyword: Zircon Place: Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Place_Keyword: Contact Point Place_Keyword: Cook Inlet Place_Keyword: Cook Inlet Basin Place_Keyword: Iliamna Quadrangle Place_Keyword: Naknek Place_Keyword: Ursus Head Stratum: Stratum_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Stratum_Keyword: Bruin Bay Fault Temporal: Temporal_Keyword_Thesaurus: Walker, J.D., Geissman, J.W., Bowring, S.A, and Babcock, L.E., comp., 2012, Geologic Time Scale v. 4.0: Geological Society of America Temporal_Keyword: Cenozoic Temporal_Keyword: Eocene Temporal_Keyword: Mesozoic Temporal_Keyword: Oligocene Temporal_Keyword: Triassic Access_Constraints: 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). Use_Constraints: 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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5039 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Data_Set_Credit: Lower 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. Cross_Reference: Citation_Information: Originator: Betka, P.M. Originator: Gillis, R.J. Publication_Date: 2014 Title: Preliminary characterization of brittle deformation on the Iniskin Peninsula: Implications for the kinematic history of the Bruin Bay fault system, lower Cook Inlet, Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2014-5 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 14 p Online_Linkage: http://doi.org/10.14509/29130 Cross_Reference: Citation_Information: Originator: Betka, P.M. Originator: Gillis, R.J. Publication_Date: 2015 Title: The superposition of strike-slip and reverse-slip faults in the Bruin Bay fault system, Ursus Head, lower Cook Inlet Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2015-5-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: p. 5-8 Online_Linkage: http://doi.org/10.14509/29457 Cross_Reference: Citation_Information: Originator: Betka, P.M. Originator: Gillis, R.J. Publication_Date: 2016 Title: Observations on the Bruin Bay fault system between Chinitna and Tuxedni bays, Cook Inlet, Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2016-1-10 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: p. 73-78 Online_Linkage: http://doi.org/10.14509/29544 Cross_Reference: Citation_Information: Originator: Gillis, R.J. Originator: Wartes, M.A. Originator: O'Sullivan, P.B. Publication_Date: 2011 Title: Preliminary 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 Series_Information: Series_Name: Poster and Presentation Issue_Identification: Gillis, R.J. and others, 2011 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 1 sheet Online_Linkage: http://doi.org/10.14509/23403 Cross_Reference: Citation_Information: Originator: Gillis, R.J. Originator: Swenson, R.F. Originator: Wartes, M.A. Originator: Frohman, R.A. Publication_Date: 2013 Title: Reconnaissance investigations of the Bruin Bay fault system along the western margin of lower Cook Inlet and upper Alaska Peninsula Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2013-1G Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: p. 33-37 Online_Linkage: http://doi.org/10.14509/24850 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: This 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. Logical_Consistency_Report: not applicable Completeness_Report: This data release is complete. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Sample location coordinates (in NAD27 datum) were obtained using Garmin eTrex GPS units, with typical reported accuracy of about 9 ft. Lineage: Process_Step: Process_Description: Fieldwork - Samples of igneous dikes from deformed outcrops were collected by DGGS field geologists based on their cross-cutting relationships with structural features. Process_Date: 2012 Process_Step: Process_Description: Data 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. Process_Date: 2012 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.000001 Longitude_Resolution: 0.000001 Geographic_Coordinate_Units: decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1927 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378206.40000000037 Denominator_of_Flattening_Ratio: 294.978698199999997 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Attribute_Layer_Name: geochron-data Entity_Type_Label: rdf2017-7-geochron-data Entity_Type_Definition: Geochronology lab files and applicable documentation. Entity_Type_Definition_Source: Alaska Division of Geological & Geophysical Surveys (DGGS) Detailed_Description: Entity_Type: Entity_Attribute_Layer_Name: geochron-summary Entity_Type_Label: rdf2017-7-geochron-summary Entity_Type_Definition: Identification numbers, coordinates, sample descriptions, and summary ages of each sample. Entity_Type_Definition_Source: Alaska Division of Geological & Geophysical Surveys (DGGS) Attribute: Attribute_Label: SAMPLE Attribute_Definition: Label assigned in the field to identify the sample. Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys Attribute_Domain_Values: Unrepresentable_Domain: Generic 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. Attribute: Attribute_Label: LAB_SAMPLE_NUMBER Attribute_Definition: Label used by the lab to identify the sample. Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys and Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Unrepresentable_Domain: free text Attribute: Attribute_Label: LATITUDE Attribute_Definition: Latitude, NAD27 Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 59.55316 Range_Domain_Maximum: 59.55371 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: LONGITUDE Attribute_Definition: Longitude, NAD27 Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -153.61873 Range_Domain_Maximum: -153.60832 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: DESCRIPTION Attribute_Definition: Description of the sample Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys Attribute_Domain_Values: Unrepresentable_Domain: A brief sample and/or station description. Attribute: Attribute_Label: NUM_MEASUREMENTS_USED Attribute_Definition: Number of measurements used for calculating the age. Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 8 Range_Domain_Maximum: 47 Attribute: Attribute_Label: TOTAL_MEASUREMENTS Attribute_Definition: Total number of measurements. Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 36 Range_Domain_Maximum: 49 Attribute: Attribute_Label: WMEAN_AGE_MA Attribute_Definition: Weighted mean age, in millions of years (Ma). Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 206.92 Range_Domain_Maximum: 212.49 Attribute_Units_of_Measure: Ma Attribute: Attribute_Label: MEAN_AGE_MA Attribute_Definition: Mean age, in millions of years (Ma). Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 207.14 Range_Domain_Maximum: 213.54 Attribute_Units_of_Measure: Ma Attribute: Attribute_Label: S2_FFER Attribute_Definition: 2-sigma error + fractionation-factor error Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 9.24 Range_Domain_Maximum: 9.61 Attribute: Attribute_Label: S2_STDEV_FFER Attribute_Definition: 2-sigma standard deviation on the 2-sigma error + fractionation-factor error Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 7.15 Range_Domain_Maximum: 11.46 Attribute: Attribute_Label: S2 Attribute_Definition: 2-sigma error (not including fractionation factor error) Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.96 Range_Domain_Maximum: 2.28 Attribute: Attribute_Label: S2_STDEV Attribute_Definition: 2-sigma standard deviation on the 2-sigma error (not including fractionation factor error) Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1.04 Range_Domain_Maximum: 4.05 Attribute: Attribute_Label: MSWDW Attribute_Definition: Mean 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. Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1.10 Range_Domain_Maximum: 3.42 Attribute: Attribute_Label: P_MSWDW Attribute_Definition: Statistical scatter in the MSWD - values range between 1 (good) and 0 (poor) Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.003261 Range_Domain_Maximum: 1.000000 Attribute: Attribute_Label: MEAN_U_PPM Attribute_Definition: Mean concentration of uranium (U), in parts per million (ppm). Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 340.37 Range_Domain_Maximum: 1157.97 Attribute: Attribute_Label: MEAN_TH_PPM Attribute_Definition: Mean concentration of thorium (Th), in parts per million (ppm). Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 257.01 Range_Domain_Maximum: 518.99 Attribute: Attribute_Label: MEAN_U_TH_RATIO_PPM Attribute_Definition: Mean concentration of uranium (U) divided by the mean concentration of thorium (Th); in parts per million (ppm). Attribute_Definition_Source: Apatite to Zircon, Inc. (A2Z) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1.324 Range_Domain_Maximum: 2.231 Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5039 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Resource_Description: RDF 2017-7 Distribution_Liability: 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. Standard_Order_Process: Non-digital_Form: 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. 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Fees: Contact DGGS for current pricing Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ASCII tabular files Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://doi.org/10.14509/29750 Fees: Free download Metadata_Reference_Information: Metadata_Date: 20170830 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5039 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Use_Constraints: 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. Metadata_Extensions: Online_Linkage: http://www.dggs.alaska.gov/metadata/dggs.ext Profile_Name: dggs metadata extensions