Identification_Information: Citation: Citation_Information: Originator: Gillis, R.J. Originator: Wartes, M.A. Originator: Herriott, T.M. Originator: LePain, D.L. Originator: Benowitz, J.A. Originator: Wypych, Alicja Originator: Donelick, R.A. Originator: O'Sullivan, P.B. Originator: Layer, P.W. Publication_Date: 2022 Title: 40Ar/39Ar and U-Pb geochronology of Cretaceous-Paleocene igneous rocks and Cenozoic strata of northwestern Cook Inlet, Alaska: Linkages between arc magmatism, cooling, faulting, and forearc subsidence Geospatial_Data_Presentation_Form: table Series_Information: Series_Name: Professional Report Issue_Identification: PR 125 v. 1.1 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 78 p. Online_Linkage: https://doi.org/10.14509/30554 Description: Abstract: DGGS Professional Report 125, 40Ar/39Ar and U-Pb geochronology of Cretaceous-Paleocene igneous rocks and Cenozoic strata of northwestern Cook Inlet, Alaska: Linkages between arc magmatism, cooling, faulting, and forearc subsidence, presents results from 53 40Ar/39Ar and 51 U-Pb analyses of 73 sedimentary, intrusive, and volcanic rock samples collected in the south-central Tyonek Quadrangle of southern Alaska. These data provide new age control and provenance information for igneous and sedimentary rock units throughout the study area--some of which lack prior geochronologic age assignments. The samples were collected in concert with new geologic mapping of approximately 900 square miles encompassing parts of the Late Cretaceous-Paleogene magmatic arc and Cenozoic forearc basin in south-central Alaska. Detailed stratigraphic studies of the entire Cenozoic succession were undertaken at the same time. The widespread exposures of forearc strata in the map area are surface correlatives to hydrocarbon-hosting and commercially producing units in the adjacent subsurface of Cook Inlet basin to the southeast. The results inform structural and depositional models for the Cook Inlet forearc basin that are leveraged to assess tectonic events affecting the continental margin. Intrusive crystallization dates and geochemistry of igneous rocks define episodes of arc magmatism in the region at ca. 84-78 Ma, ca. 74-71 Ma, ca. 69-65 Ma, and ca. 62-57 Ma. Mafic and intermediate volcanics with arc to intra-plate signatures are restricted to a period of reduced arc magmatism from about 57 to 47 Ma. Bedrock cooling from approximately 550 degrees C to below 150 degrees C occurred monotonically, but at varying rates. The cooling trends are consistent with thermal conduction after shallow melt emplacement followed by structurally controlled cooling during the early Paleocene. New dates of reworked tephras from Cenozoic forearc strata constrain the depositional age of the West Foreland Formation at a maximum of ca. 47 Ma to ca. 38 Ma. The dates bracket renewed arc volcanism and middle Eocene syntectonic sedimentation at the western basin margin. More sparsely dated Tyonek and Beluga formations produced zircon U- Pb maximum depositional dates of ca. 15.3-15.2 Ma, and ca. 11.2-9.7 Ma, respectively. These dates are used to anchor a large existing palynologic dataset from the area. New and previously published palynologic results indicate that the oldest Hemlock Conglomerate extends to middle Eocene and thus is partially contemporaneous with West Foreland deposition. Sediment accumulation rates calculated from dated stratigraphic intervals and revised stratigraphic age ranges of the West Foreland Formation and Hemlock Conglomerate suggest a pronounced decrease in basin subsidence during Hemlock deposition followed by an order of magnitude increase in sediment accumulation rates by the middle Miocene. Conglomerate clast dates and detrital grains from reworked tephras provide additional insights into sediment provenance that help refine a depositional model for the Paleogene basin margin. The results highlight the transition from high-gradient, small-catchment alluvial systems sourced from the structurally exhumed arc to a mature, trunk fluvial network distributing a mixed sediment load from proximal arc and distal basement sources during a period of low basin accommodation. Dextral faults extending for nearly 250 km from the upper Cook Inlet to the Matanuska Valley constituted a linked structural system from late Paleocene to middle Eocene that created transtensional depocenters at major fault step-overs along the northwestern and northern margins of the forearc basin. Orogen-parallel extension of the arc region directly to the north is a mechanical consequence of an eastward increase in strike-slip displacement along the fault system. The resulting normal faults produced conduits for magmas sourced from a depleted mantle reservoir during a lull in arc magmatism, and likely facilitated subsidence in the Susitna successor basin. Paleocene to Eocene initiation of dextral strike-slip faults and extension of the arc region supports models for Paleogene oroclinal bending of Alaska. All files are available from the DGGS website: http://doi.org/10.14509/30554. Purpose: The Cook Inlet basin analysis program aims to produce more accurate and modern geologic maps and supporting datasets to facilitate developing a better understanding of the Cook Inlet petroleum system's near-margin stratigraphic and structural components. Supplemental_Information: >Appendix A: Analytical Methods >Appendix B: Zircon U-Pb data >Appendix C: 40Ar/39Ar data >Appendix D: Description and age interpretations for Cretaceous intrusive rock samples >Appendix E: Description and age interpretations for Paleocene intrusive rock samples >Appendix F: Description and age interpretations for Cretaceous and Paleocene volcanic rock samples >Appendix G: Description and age interpretations for West Foreland Formation and Kenai Group samples >Appendix H: Summary table for all geochronologic dates including locations >Appendix I: Summary table for thermochronologic cooling rates >Appendix J: Summary table for major oxide samples descriptions, classification codes, and locations Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2006 Ending_Date: 2021 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -152.257930 East_Bounding_Coordinate: -150.707310 North_Bounding_Coordinate: 61.761010 South_Bounding_Coordinate: 61.017140 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Theme_Keyword: Alluvial Theme_Keyword: Analyses Theme_Keyword: Ar-Ar Theme_Keyword: Basalt Theme_Keyword: Basins Theme_Keyword: Bedrock Theme_Keyword: Conglomerate Theme_Keyword: DGGS Theme_Keyword: Diorite Theme_Keyword: Energy Theme_Keyword: Energy Resources Theme_Keyword: Exhumation Theme_Keyword: Faults Theme_Keyword: Fluvial Theme_Keyword: Forearc Basin Theme_Keyword: Formations Theme_Keyword: Geochemistry Theme_Keyword: Geochronology Theme_Keyword: Geologic Theme_Keyword: Geological Process Theme_Keyword: Geology Theme_Keyword: Geothermometry Theme_Keyword: Granite Theme_Keyword: Granodiorite Theme_Keyword: Hornblende Theme_Keyword: Igneous Theme_Keyword: Interpretation Theme_Keyword: Methods Theme_Keyword: Oil Basins Theme_Keyword: Oil Development Theme_Keyword: Oil and Gas Theme_Keyword: Oil and Gas Basin Theme_Keyword: Petroleum Theme_Keyword: Plagioclase Theme_Keyword: Plutonic Theme_Keyword: Plutons Theme_Keyword: Potassium Theme_Keyword: Provenance Theme_Keyword: Reservoir Theme_Keyword: Resources Theme_Keyword: Rocks Theme_Keyword: STATEMAP Project Theme_Keyword: Sandstone Theme_Keyword: Sediment Theme_Keyword: Sedimentary Theme_Keyword: Sedimentation Theme_Keyword: Stratigraphy Theme_Keyword: Structure Theme_Keyword: Subduction Theme_Keyword: Subsidence Theme_Keyword: Surface Theme_Keyword: Tectonics Theme_Keyword: Tephra Theme_Keyword: Thermochronology Theme_Keyword: Tuff Theme_Keyword: U-Pb Theme_Keyword: Unconformity Theme_Keyword: Uplift Theme_Keyword: Volcanic Theme_Keyword: Zircon Place: Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Place_Keyword: Beluga Mountain Place_Keyword: Beluga River Place_Keyword: Bishop Creek Place_Keyword: Chuitna River Place_Keyword: Clear Creek Place_Keyword: Coffee Creek Place_Keyword: Cook Inlet Place_Keyword: Deep Creek Place_Keyword: Felt Lake Place_Keyword: Granite Creek Place_Keyword: Granite Point Place_Keyword: Kustatan River Place_Keyword: Little Mount Susitna Place_Keyword: Lone Creek Place_Keyword: Lone Ridge Place_Keyword: McArthur River Place_Keyword: Mount Susitna Place_Keyword: Old Tyonek Creek Place_Keyword: Olson Creek Place_Keyword: Pierce Creek Place_Keyword: Scarp Creek Place_Keyword: Southcentral Alaska Place_Keyword: Straight Creek Place_Keyword: Talachulitna River Place_Keyword: Texas Creek Place_Keyword: Theodore River Stratum: Stratum_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Stratum_Keyword: Beluga Formation Stratum_Keyword: Hemlock Conglomerate Stratum_Keyword: Kaloa Deposits Stratum_Keyword: Sterling Formation Stratum_Keyword: Tyonek Formation Stratum_Keyword: West Foreland Formation 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: Cretaceous Temporal_Keyword: Eocene Temporal_Keyword: Holocene Temporal_Keyword: Jurassic Temporal_Keyword: Mesozoic Temporal_Keyword: Miocene Temporal_Keyword: Neogene Temporal_Keyword: Oligocene Temporal_Keyword: Paleocene Temporal_Keyword: Paleogene Temporal_Keyword: Pliocene Temporal_Keyword: Quaternary Temporal_Keyword: Tertiary 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 Contact_Instructions: Please 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. Data_Set_Credit: Discussions with Ken Helmold, Richard Stanley, Bob Swenson, Kate Bull, Ron Cole, Ken Ridgway, Emily Finzel, Dick Reger, Jeff Trop, Jamey Jones, Erin Todd, Rick Levinson, Jake Mongrain, Richard Lease, Peter Haeussler, Richard Koehler, and Paul Betka improved our understanding of southern Alaska geology and refined our interpretations. Erin Todd kindly commented on our interpretation and discussion of the igneous geochemistry. David Doherty introduced us to the area prior to commencing field studies and provided valuable insights. Mark Schmitz kindly provided his spreadsheet for calculating maximum depositional dates. Samples were collected by Larry Freeman, David LePain, Bob Gillis, Brent Elliott, Marwan Wartes, Trystan Herriott, David Mauel, Emily Finzel, Jake Mongrain, and Ken Ridgway. University of Alaska, Fairbanks undergraduate interns Keane Richards and Kandace Krecji helped with sample logistics and data entry and provided assistance in the field. Pathfinder Aviation and pilots Merlin (Spanky) Handley, Marty Staufer, Chuck Redd, Ray Hodges, and Hightower Paxton, along with Tom (Rat) Ratledge of Yukon Helicopters, safely and skillfully transported us to every corner and creek in the field area. Jack Barber at Alaska Air Taxi flew personnel and gear to our field base camp. Bob Freeman at Three-Mile Camp kept us well fed and dry during the record-breaking 30 consecutive days of rain in the summer of 2010. Land access was kindly permitted by Cook Inlet Region, Inc. (CIRI) and Tyonek Native Corporation. This project was funded by State of Alaska Capital Improvement Project funds and the U.S. Geological Survey's National Cooperative Geologic Mapping Program STATEMAP component (award numbers G09AC00177 and G10AC00321). Reviews by Emily Finzel and James V. Jones III helped to substantially focus the manuscript and improve its contents. Disclaimer: The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey. Cross_Reference: Citation_Information: Originator: Alaska Division of Geological & Geophysical Surveys Publication_Date: 1978 Title: Short Notes on Alaskan Geology - 1978 Series_Information: Series_Name: Geologic Report Issue_Identification: GR 61 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 41 p Online_Linkage: https://doi.org/10.14509/407 Cross_Reference: Citation_Information: Originator: Fuchs, W.A. Publication_Date: 2019 Title: Geologic map of the Castle Mountain-Caribou fault system, Talkeetna Mountains, Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2017-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 57 p., 2 sheets, scale 1:24,000 Online_Linkage: https://doi.org/10.14509/29715 Cross_Reference: Citation_Information: Originator: Gillis, R.J. Originator: LePain, D.L. Originator: Ridgway, K.D. Originator: Finzel, E.S. Publication_Date: 2009 Title: A reconnaissance view of an unnamed fault near Capps Glacier, northwestern Cook Inlet basin, and its potential as a regional-scale, basin-controlling structure Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2009-3 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 9 p Online_Linkage: https://doi.org/10.14509/19503 Cross_Reference: Citation_Information: Originator: Gregersen, L.S. Originator: Shellenbaum, D.P. Publication_Date: 2016 Title: Top Mesozoic unconformity subcrop map, Cook Inlet basin, Alaska Series_Information: Series_Name: Report of Investigation Issue_Identification: RI 2016-4 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 1 sheet, scale 1:500,000 Online_Linkage: https://doi.org/10.14509/29658 Cross_Reference: Citation_Information: Originator: Hartman, D.C. Originator: Pessel, G.H. Originator: McGee, D.L. Publication_Date: 1974 Title: Stratigraphy of the Kenai group, Cook Inlet Series_Information: Series_Name: Alaska Open-File Report Issue_Identification: AOF 49 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 7 p., 11 sheets Online_Linkage: https://doi.org/10.14509/149 Cross_Reference: Citation_Information: Originator: Herriott, T.M. Originator: Wartes, M.A. Originator: Stanley, R.G. Originator: Decker, P.L. Originator: Helmold, K.P. Originator: Harun, N.T. Publication_Date: 2018 Title: Sequence-stratigraphic framework of the Middle Jurassic Chinitna Formation, Cook Inlet forearc basin, south-central Alaska (presentation): Alaska Geological Society, 20 March 2018, Anchorage, Alaska Series_Information: Series_Name: Poster and Presentation Issue_Identification: Herriott, T.M. and others, 2018 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 77 p Online_Linkage: https://doi.org/10.14509/30031 Cross_Reference: Citation_Information: Originator: Koehler, R.D. Originator: Reger, R.D. Publication_Date: 2011 Title: Reconnaissance evaluation of the Lake Clark fault, Tyonek area, Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2011-1 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 8 p Online_Linkage: https://doi.org/10.14509/22221 Cross_Reference: Citation_Information: Originator: Koehler, R.D. Originator: Reger, R.D. Originator: Frohman, R.A. Publication_Date: 2012 Title: The Castle Mountain fault, south-central Alaska: New lidar-based observations on the sense of slip, Eos Trans. AGU, Fall Meet. Suppl., Abstract #S53D-2530 Series_Information: Series_Name: Poster and Presentation Issue_Identification: Koehler, R.D. and others, 2012 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 1 p., 1 sheet Online_Linkage: https://doi.org/10.14509/24724 Cross_Reference: Citation_Information: Originator: Reger, R.D. Publication_Date: 2009 Title: Reinterpretation of the Kaloa deposits near Granite Point, northwestern Cook Inlet, Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2009-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 8 p Online_Linkage: https://doi.org/10.14509/18241 Cross_Reference: Citation_Information: Originator: Shellenbaum, D.P. Originator: Gregersen, L.S. Originator: Delaney, P.R. Publication_Date: 2010 Title: Top Mesozoic unconformity depth map of the Cook Inlet basin, Alaska Series_Information: Series_Name: Report of Investigation Issue_Identification: RI 2010-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 1 sheet, scale 1:500,000 Online_Linkage: https://doi.org/10.14509/21961 Cross_Reference: Citation_Information: Originator: Stanley, R.G. Originator: Haeussler, P.J. Originator: Benowitz, J.A. Originator: Goodman, D.K. Originator: Ravn, R.L. Originator: Shellenbaum, D.P. Originator: Saltus, R.W. Originator: Lewis, K.A. Originator: Potter, C.J. Publication_Date: 2013 Title: New stratigraphic revelations in the subsurface Susitna basin, south-central Alaska, from geochronology and biostratigraphy [poster]: GSA Cordilleran Section Meeting, Fresno, CA, May 22, 2013 Series_Information: Series_Name: Poster and Presentation Issue_Identification: Stanley, R.G. and others, 2013 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 1 sheet Online_Linkage: https://doi.org/10.14509/26887 Cross_Reference: Citation_Information: Originator: Zippi, P.A. Originator: Gillis, R.J. Originator: Montayne, Simone Originator: Loveland, A.M. Publication_Date: 2021 Title: Palynological and thermal maturity analysis of outcrop samples from the Kenai, Seldovia, and Tyonek quadrangles, Cook Inlet region, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2021-8 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 4 p Online_Linkage: https://doi.org/10.14509/30660 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: This data collection provides a compilation of detailed 40Ar/39Ar and U-Pb geochronology analyses and geochemical summary data used to support the observations and interpretations presented in the accompanying report. Uncertainties and attribute accuracy vary according to the data product. We encourage users to review the report and accompanying method documentation to better understand the methods and limitations of the source data and analytical results. Logical_Consistency_Report: Not applicable Completeness_Report: This data release is complete. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Location data were collected using handheld recreational grade Garmin GPS units. These devices have a typical reported error of 9 to 21 feet. However, the actual location accuracy of the sample coordinates varies according to the observer's sampling context and recording conventions. Many samples were collected during poor weather conditions and from deep ravines where GPS to satellite connectivity was not ideal. In conjunction with this publication release, the authors have carefully reviewed GPS-reported locations relative base map imagery to verify that each sample is appropriately located relative to the scale of the research and adjusted locations to coincide with base map imagery when appropriate. Consequently, users may find functionally insignificant sample location differences throughout various Cook Inlet project publications. Locations for samples collected along a measured stratigraphic section reflect the GPS reading at the base of the measured section. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Freeman, L.K. Originator: Gillis, R.J. Originator: Elliott, B.A. Originator: Wypych, Alicja Publication_Date: 2016 Title: Major-oxide and trace-element geochemical data from rocks collected in 2010 in the Tyonek Quadrangle, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2016-5 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 2 p Online_Linkage: https://doi.org/10.14509/29651 Type_of_Source_Media: data Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2016 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: Freeman, L.K. and others, 2016 Source_Contribution: geochemistry Process_Step: Process_Description: Field data collection - Approximately 10-15 kg of the freshest, most unaltered rock available were collected for most samples. Phaneritic intrusive rocks with unaltered mafic mineral phases and visible striae on crystal faces were targeted for collection, as were aphanitic rocks free of chloritic alteration or oxidation. Thin bentonitic volcaniclastic beds and tonsteins collected from coals were carefully excavated to avoid contamination. Sample locations were recorded using modern, hand-held GPS units set to the NAD 27 datum with typical horizontal precision of 9 to 21 feet. Process_Date: 2011 Process_Step: Process_Description: Geochemistry - Selected samples were analyzed for major-oxide and trace-elements. Source_Used_Citation_Abbreviation: Freeman, L.K. and others, 2016 Process_Date: 2011 Process_Step: Process_Description: Zircon U-Pb - Selected samples were analyzed for Zircon U-Pb geochronology using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Zircon U-Pb analytical methods are outlined in Appendix A. Process_Date: 2011 Process_Step: Process_Description: 40AR/39AR - Selected intrusive, volcanic, and volcaniclastic rock samples were submitted to the UAF Geochronology Laboratory for 40Ar/39Ar analysis. 40Ar/39A analytical methods are outlined in Appendix A. Process_Date: 2011 Process_Step: Process_Description: Version 1.1 - We corrected data reporting typographic errors for samples: 10BAE353, 07BG275, 10LF298, 07BG256, 07BG257, 07DL80-4.2, 07DL80-67.5, 07DL076, 08DL055. Process_Date: 2021 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: .0000001 Longitude_Resolution: .0000001 Geographic_Coordinate_Units: decimal degrees Geodetic_Model: Horizontal_Datum_Name: NAD27 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378206.40000000037 Denominator_of_Flattening_Ratio: 294.978698199999997 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Appendix A Entity_Type_Definition: Analytical Methods Entity_Type_Definition_Source: DGGS, Apatite to Zircon, INC., GeoSep Services, UAF Geochronology Laboratory Entity_Attribute_Layer_Name: Appendix A Detailed_Description: Entity_Type: Entity_Type_Label: Appendix B Entity_Type_Definition: Zircon U-Pb data Entity_Type_Definition_Source: DGGS, Apatite to Zircon, INC., GeoSep Services, Entity_Attribute_Layer_Name: Appendix B Detailed_Description: Entity_Type: Entity_Type_Label: Appendix C Entity_Type_Definition: 40Ar/39Ar data Entity_Type_Definition_Source: DGGS, UAF Geochronology Laboratory Entity_Attribute_Layer_Name: Appendix C Detailed_Description: Entity_Type: Entity_Type_Label: Appendix D Entity_Type_Definition: Description and age interpretations for Cretaceous intrusive rock samples Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: Appendix D Detailed_Description: Entity_Type: Entity_Type_Label: Appendix E Entity_Type_Definition: Description and age interpretations for Paleocene intrusive rock samples Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: Appendix E Detailed_Description: Entity_Type: Entity_Type_Label: Appendix F Entity_Type_Definition: Description and age interpretations for Cretaceous and Paleocene volcanic rock samples Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: Appendix F Detailed_Description: Entity_Type: Entity_Type_Label: Appendix G Entity_Type_Definition: Description and age interpretations for West Foreland Formation and Kenai Group samples Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: Appendix G Detailed_Description: Entity_Type: Entity_Type_Label: Appendix H Entity_Type_Definition: Summary table for all geochronologic dates including locations Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: Appendix H Detailed_Description: Entity_Type: Entity_Type_Label: Appendix I Entity_Type_Definition: Summary table for thermochronologic cooling rates Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: Appendix I Detailed_Description: Entity_Type: Entity_Type_Label: Appendix J Entity_Type_Definition: Summary table for major oxide samples descriptions, classification codes, and locations Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: Appendix J 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 Contact_Instructions: Please 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. Resource_Description: PR 125 v. 1.1 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. 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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: https://dggs.alaska.gov/metadata/dggs.ext Profile_Name: dggs metadata extensions