Identification_Information: Citation: Citation_Information: Originator: Herriott, T.M. Originator: Wartes, M.A. Originator: O'Sullivan, P.B. Originator: Gillis, R.J. Publication_Date: 2019 Title: Detrital zircon maximum depositional dates for the Jurassic Chinitna and Naknek Formations, lower Cook Inlet, Alaska: A preliminary view Geospatial_Data_Presentation_Form: report and digital data Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2019-5 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 11 p. Online_Linkage: http://doi.org/10.14509/30180 Description: Abstract: This report and it's accompanying analytical data present uranium-lead (U-Pb) detrital zircon dates for the Paveloff Siltstone Member of the Chinitna Formation and the lower sandstone member of the Naknek Formations, permitting insights into the depositional ages of these units and revealing discrepancies between this new geochronology and the long-established biostratigraphy and/or the current geologic time scale. We conducted laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) U-Pb detrital zircon geochronology of two sandstone samples from Oil Bay in Cook Inlet, Alaska. Samples were prepared and analyzed by GeoSep Services. All files are available from the DGGS website: http://doi.org/10.14509/30180. Purpose: The Alaska Division of Geological & Geophysical Surveys leads a basin analysis program in Cook Inlet of south-central Alaska. This program aims to improve understanding of the region's petroleum geology and includes work in the Iniskin Bay-Tuxedni Bay area of lower Cook Inlet. A major focus of these studies is the Jurassic forearc stratigraphy, which hosts the basin's oil source rocks. Robust biostratigraphic constraints provide temporal context for this economically significant Jurassic succession. However, prior to this work, no modern radioisotopic dates were available to render absolute age control. Chronostratigraphy is an integral part of basin analysis, and geochronologic dates are commonly obtained to refine existing frameworks that have historically relied on paleontologic collections. Supplemental_Information: >geochron-data: Geochronology lab files and applicable documentation. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2010 Ending_Date: 2019 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -153.28048 East_Bounding_Coordinate: -153.27545 North_Bounding_Coordinate: 59.66939 South_Bounding_Coordinate: 59.66258 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Theme_Keyword: Basins Theme_Keyword: Detrital Zircon Theme_Keyword: Forearc Basin Theme_Keyword: Formations Theme_Keyword: Gas Theme_Keyword: Geochronology Theme_Keyword: Geologic Theme_Keyword: Geology Theme_Keyword: Lead Theme_Keyword: Methods Theme_Keyword: Nonmarine Theme_Keyword: Petroleum Theme_Keyword: Provenance Theme_Keyword: Resources Theme_Keyword: Rocks Theme_Keyword: Sediment Theme_Keyword: Sedimentary Theme_Keyword: Sedimentation Theme_Keyword: Sedimentology Theme_Keyword: Siltstone Theme_Keyword: Stratigraphy Theme_Keyword: Uranium Theme_Keyword: Volcanic Theme_Keyword: Zircon Place: Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Place_Keyword: Cook Inlet Place_Keyword: Iniskin Bay Place_Keyword: Oil Bay Place_Keyword: Tuxedni Bay Stratum: Stratum_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Stratum_Keyword: Chinitna Formation Stratum_Keyword: Naknek Formation Stratum_Keyword: Paveloff Siltstone Member Stratum_Keyword: Tuxedni Group 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: Callovian Temporal_Keyword: Jurassic Temporal_Keyword: Kimmeridgian Temporal_Keyword: Oxfordian 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)451-5020 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: The State of Alaska funded this work. Merlin "Spanky" Handley safely transported our field crew to collect samples in Oil Bay. We thank Alaska Homestead Lodge for their hospitality. Discussions with Jamey Jones, Richard Lease, Matt Rioux, Jim Crowley, Mark Schmitz, and Mareca Guthrie improved this study. Kristen Janssen formatted this report, and Simone Montayne managed the metadata. Dave LePain and Mandy Willingham provided reviews that improved this paper. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: These data are being released in the DGGS Preliminary Interpretive Report series. This category is intended for the timely release of maps and reports with preliminary interpretation of geology or analytical data. The publication has undergone limited peer review but does not necessarily conform to DGGS editorial standards. Interpretations or conclusions contained in this publication are subject to change. Logical_Consistency_Report: not applicable Completeness_Report: This data release is complete but does not include comprehensive metadata for all of the analytical fields in the data tables. The data and limited metadata provided by the originating lab were deemed sufficiently understandable for the intent of this analysis, and attempts to obtain more comprehensive documentation from the lab were unsuccessful. Requests for additional information regarding the parameters and definitions of the analytical values should be directed to the originating lab. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Locations were measured using a recreational grade GPS. Note that location coordinates for sample 09BG010-14.5C (N59.66258° W153.27545° [NAD83]) are tied to the base of a measured section that lies 14.5 m stratigraphically below the sampled bed. Lineage: Process_Step: Process_Description: Sample selection - DGGS field geologists collected fresh, unweathered, bulk interval samples from bedrock outcrops. See accompanying report for sample locations and descriptions. Process_Date: 2009 Process_Step: Process_Description: Data analysis - We conducted laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) U-Pb detrital zircon geochronology of two sandstone samples from Oil Bay in Cook Inlet, Alaska. Samples were prepared and analyzed by GeoSep Services. Three maximum depositional dates were determined for each sample: youngest single grain; and youngest mode of the kernel density estimation. See accompanying report for additional discussion of analytical and statistical methodology. Process_Date: 2018 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.0001 Longitude_Resolution: 0.0001 Geographic_Coordinate_Units: decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: GRS 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257222101000025 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: pir2019-5-geochron-data-09BG010-14.5c.xlsx, pir2019-5-geochron-data-09BG023a.xlsx, pir2019-5-geochron-data-documentation.xlsx Entity_Type_Definition: Geochronology lab files and applicable documentation. Entity_Type_Definition_Source: this report Entity_Attribute_Layer_Name: geochron-data 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)451-5020 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: PIR 2019-5 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. 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. 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/10.14509/30180 Fees: Free download Metadata_Reference_Information: Metadata_Date: 20190917 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Person: Simone Montayne 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)451-5020 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