Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 1999 Title: Alaska Radiometric Ages Geospatial_Data_Presentation_Form: tabular digital data Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 1999 Currentness_Reference: Date on which data provided online was extracted from the database Description: Abstract: The Alaska Radiometric Age file is a database of radiometric ages of rocks or minerals sampled from Alaska. The data was collected from professional publications and/or received from researchers and used by permission. Purpose: Database of radiometric ages is designed to aid in the research of geochronologic information of Alaska rocks and minerals. Users should always review the cited publications for more complete descriptions of the samples, analyses, and geologic interpretation. Supplemental_Information: The radiometric dates in this data set were collected from published sources through 1990(approximately). The dates were compiled over many years and published as a map in the series Decade of North American Geology, by the Geological Society of America. Status: Progress: In work Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: 172.0 East_Bounding_Coordinate: -130.0 North_Bounding_Coordinate: 72.0 South_Bounding_Coordinate: 54.0 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: geochronology Theme_Keyword: radiometric age Theme_Keyword: radiometric date Theme_Keyword: geologic time Theme_Keyword: potassium-argon Theme_Keyword: uranium-lead Place: Place_Keyword_Thesaurus: None Place_Keyword: Alaska Access_Constraints: None Use_Constraints: The U.S. Geological Survey makes no warranties related to the accuracy of the data and users are required to determine the usability for any particular purpose. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nora Shew Contact_Address: Address_Type: mailing and physical Address: 4200 University Drive City: Anchorage State_or_Province: AK Postal_Code: 99508-4667 Country: U.S.A. Contact_Voice_Telephone: 907-561-1181 Contact_Electronic_Mail_Address: nshew@usgs.gov Data_Set_Credit: The radiometric age data base has been maintained since the mid-1970's. Compilers include: F.H. Wilson, Nora Shew, G.D. DuBois, and Shawn Dadisman. Data_Quality_Information: Logical_Consistency_Report: Generally, the radiometric ages in the database are as published. Some potassium-argon ages have been recalculated using the decay constants recommended by the IUGS Subcommission on Geochronology in 1976. Dates that have been recalculated are noted in the 'Comments' field. Completeness_Report: The radiometric age database does not include the analytical information which is often found in the published sources. Also, the database records do not contain the geologic interpretation of the analysis. Users of this database should always /refer to the publications listed in the 'Reference' field for detailed information about each analysis. Lineage: Process_Step: Process_Description: The Alaska radiometric age file is a compilation of published and other released radiometric dates on rocks and minerals of Alaska. The precision of the analyses and the locations of the samples vary widely from the various sources. This compilation has not attempted to interpret the data. Users of this data should always refer to the published sources of the information. This database contains for each record: location, dating method, rock type, mineral/phase dated, age (in millions of years), comments, and references. The data was imported into Microsoft Access, brought into ArcView3.1 as an event theme, and then converted into a shape file. Process_Date: 1999 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nora Shew Contact_Address: Address_Type: mailing and physical Address: 4200 University Drive City: Anchorage State_or_Province: AK Postal_Code: 99508-4667 Country: USA Contact_Voice_Telephone: 907-561-1181 Contact_Electronic_Mail_Address: nshew@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.002 Longitude_Resolution: 0.002 Geographic_Coordinate_Units: Decimal degrees Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: points Entity_Type_Definition: Characteristics of points in shape table. Attribute: Attribute_Label: Quad Attribute_Definition: Name of 1:250,000 scale quadrangle Attribute_Definition_Source: USGS Geographic Names Information System Attribute_Domain_Values: Unrepresentable_Domain: Name of 1:250,000 scale quadrangle. Attribute: Attribute_Label: Latdeg Attribute_Definition: Degree of latitude Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 50 Range_Domain_Maximum: 70 Attribute_Units_of_Measure: degrees Attribute_Measurement_Resolution: 1. Attribute: Attribute_Label: Latmin Attribute_Definition: Minute of latitude Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.0 Range_Domain_Maximum: 59.9 Attribute_Units_of_Measure: minutes Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: Latdir Attribute_Definition: Direction of latitude Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: N Enumerated_Domain_Value_Definition: North Attribute: Attribute_Label: Londeg Attribute_Definition: Degree of longitude Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 126 Range_Domain_Maximum: 179 Attribute_Units_of_Measure: degrees Attribute_Measurement_Resolution: 1. Attribute: Attribute_Label: Lonmin Attribute_Definition: Minute of longitude Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.0 Range_Domain_Maximum: 59.9 Attribute_Units_of_Measure: minutes Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: londir Attribute_Definition: Direction of longitude Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: E Enumerated_Domain_Value_Definition: East Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: W Enumerated_Domain_Value_Definition: West Attribute: Attribute_Label: Sample Attribute_Definition: Sample ID from published source. If none was given in the cited source, then a sample id was created for this database. Attribute_Domain_Values: Unrepresentable_Domain: free text Attribute: Attribute_Label: Rock Attribute_Definition: Rock name or type Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: ADAM Enumerated_Domain_Value_Definition: adamellite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: AGNS Enumerated_Domain_Value_Definition: augen gneiss Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: ALSK Enumerated_Domain_Value_Definition: alaskite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: ALT Enumerated_Domain_Value_Definition: altered Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: AMPH Enumerated_Domain_Value_Definition: amphibolite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: AND Enumerated_Domain_Value_Definition: andesite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: APL Enumerated_Domain_Value_Definition: aplite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: ASH Enumerated_Domain_Value_Definition: ash Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: BAS Enumerated_Domain_Value_Definition: basalt Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: BIOT Enumerated_Domain_Value_Definition: biotitite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: BENT Enumerated_Domain_Value_Definition: bentonite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: BSCH Enumerated_Domain_Value_Definition: blueschist Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: BREC Enumerated_Domain_Value_Definition: breccia Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: CG Enumerated_Domain_Value_Definition: conglomerate Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: DAC Enumerated_Domain_Value_Definition: dacite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: DI Enumerated_Domain_Value_Definition: diorite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: DIA Enumerated_Domain_Value_Definition: diabase Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: ECLG Enumerated_Domain_Value_Definition: eclogite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: FELS Enumerated_Domain_Value_Definition: felsite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GAB Enumerated_Domain_Value_Definition: gabbro Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GDI Enumerated_Domain_Value_Definition: granodiorite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GLASS Enumerated_Domain_Value_Definition: glass Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GNLT Enumerated_Domain_Value_Definition: granulite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GNS Enumerated_Domain_Value_Definition: gneiss Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GNST Enumerated_Domain_Value_Definition: greenstone Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GR Enumerated_Domain_Value_Definition: granite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GRTD Enumerated_Domain_Value_Definition: granitoid Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GSCH Enumerated_Domain_Value_Definition: greenschist Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: HBDT Enumerated_Domain_Value_Definition: hornblendite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: HFLS Enumerated_Domain_Value_Definition: hornfels Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: INTR Enumerated_Domain_Value_Definition: intrusive Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: LAMP Enumerated_Domain_Value_Definition: lamprophyre Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: LAT Enumerated_Domain_Value_Definition: latite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: LBAS Enumerated_Domain_Value_Definition: leucobasalt Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: LGAB Enumerated_Domain_Value_Definition: leucogabbro Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: MAF Enumerated_Domain_Value_Definition: mafic Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: MAR Enumerated_Domain_Value_Definition: marble Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: META Enumerated_Domain_Value_Definition: metamorphic Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: METB Enumerated_Domain_Value_Definition: metabasite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: METP Enumerated_Domain_Value_Definition: metapelite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: METV Enumerated_Domain_Value_Definition: metavolcanic Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: METW Enumerated_Domain_Value_Definition: metawacke Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: MIG Enumerated_Domain_Value_Definition: migmatite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: MON Enumerated_Domain_Value_Definition: monzonite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: MONDI Enumerated_Domain_Value_Definition: monzodiorite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: MYLT Enumerated_Domain_Value_Definition: mylonite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: OTHER Enumerated_Domain_Value_Definition: other (rock identified in comments field) Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: PEG Enumerated_Domain_Value_Definition: pegmatite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: PHYL Enumerated_Domain_Value_Definition: phyllite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: PORPH Enumerated_Domain_Value_Definition: porphyry Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: PYRX Enumerated_Domain_Value_Definition: pyroxenite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Q DI Enumerated_Domain_Value_Definition: quartz diorite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: QMD Enumerated_Domain_Value_Definition: quartz monzodiorite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: QMON Enumerated_Domain_Value_Definition: quartz monzonite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: QS Enumerated_Domain_Value_Definition: quartz sericite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: QTZT Enumerated_Domain_Value_Definition: quartzite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: RHY Enumerated_Domain_Value_Definition: rhyolite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SBREC Enumerated_Domain_Value_Definition: sedimentary breccia Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SCH Enumerated_Domain_Value_Definition: schist Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SERP Enumerated_Domain_Value_Definition: serpentinite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SKARN Enumerated_Domain_Value_Definition: skarn Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SS Enumerated_Domain_Value_Definition: sandstone Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SY Enumerated_Domain_Value_Definition: syenite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: TON Enumerated_Domain_Value_Definition: tonalite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: TRCH Enumerated_Domain_Value_Definition: trachyte Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: TROND Enumerated_Domain_Value_Definition: trondjemite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: TUFF Enumerated_Domain_Value_Definition: tuff Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: UMAF Enumerated_Domain_Value_Definition: ultramafic Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: VOL Enumerated_Domain_Value_Definition: volcanic Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: UNID Enumerated_Domain_Value_Definition: unidentified Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: XENO Enumerated_Domain_Value_Definition: xenolith Attribute: Attribute_Label: Method Attribute_Definition: Isotopic dating method Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: A Enumerated_Domain_Value_Definition: Pb-alpha Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: F Enumerated_Domain_Value_Definition: Fission track Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: K Enumerated_Domain_Value_Definition: K-Ar Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: P Enumerated_Domain_Value_Definition: Pb methods Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: R Enumerated_Domain_Value_Definition: Rb-Sr Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: S Enumerated_Domain_Value_Definition: Sm-Nd Attribute: Attribute_Label: Mineral Attribute_Definition: Mineral or phase dated from sample; or denotes that date is calculated from an isochron. Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: AC Enumerated_Domain_Value_Definition: actinolite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: AM Enumerated_Domain_Value_Definition: amphibole Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: AP Enumerated_Domain_Value_Definition: apatite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: AW Enumerated_Domain_Value_Definition: anorthoclase Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: BI Enumerated_Domain_Value_Definition: biotite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: CH Enumerated_Domain_Value_Definition: chlorite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: FD Enumerated_Domain_Value_Definition: feldspar Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GL Enumerated_Domain_Value_Definition: glass Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GP Enumerated_Domain_Value_Definition: glaucophane Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: HO Enumerated_Domain_Value_Definition: hornblende Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: IC Enumerated_Domain_Value_Definition: isochron Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: KF Enumerated_Domain_Value_Definition: K-feldspar Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: MI Enumerated_Domain_Value_Definition: mica Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: MU Enumerated_Domain_Value_Definition: muscovite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: OT Enumerated_Domain_Value_Definition: other (mineral identified in comments field) Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: PA Enumerated_Domain_Value_Definition: paragonite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: PH Enumerated_Domain_Value_Definition: phengnite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: PL Enumerated_Domain_Value_Definition: plagioclase Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: PP Enumerated_Domain_Value_Definition: phologopite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: PY Enumerated_Domain_Value_Definition: pyroxene Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: RI Enumerated_Domain_Value_Definition: riebeckite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SA Enumerated_Domain_Value_Definition: sanidine Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SE Enumerated_Domain_Value_Definition: sericite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SP Enumerated_Domain_Value_Definition: sphene Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: TR Enumerated_Domain_Value_Definition: tremolite Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: UN Enumerated_Domain_Value_Definition: unknown Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: WR Enumerated_Domain_Value_Definition: whole rock Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: ZI Enumerated_Domain_Value_Definition: zircon Attribute: Attribute_Label: Age m.y. Attribute_Definition: Age of sample in millions of years Attribute_Domain_Values: Unrepresentable_Domain: positive number Attribute: Attribute_Label: Comment Attribute_Definition: Field for free text. Attribute_Domain_Values: Unrepresentable_Domain: free text Attribute: Attribute_Label: Ref Attribute_Definition: Reference of data sample. Attribute_Domain_Values: Unrepresentable_Domain: free text Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Tom Kress Contact_Address: Address_Type: mailing address Address: 12201 Sunrise Valley Drive MS954 City: Reston State_or_Province: VA Postal_Code: 20192 Country: USA Contact_Voice_Telephone: 703-648-6328 Contact_Electronic_Mail_Address: thkress@usgs.gov Resource_Description: akages.shp Distribution_Liability: The U.S. Geological Survey (USGS) provides this point data "as is." The USGS make no guarantee or warranty concerning the accuracy of information contained in the dataset. Further, the USGS makes no warranties, either expressed or implied, as to any other matter whatsoever, including, without limitation, the condition of the product, or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although this data has bee processed successfully on computers at the USGS, no warranty, express or implied, is made by the USGS regarding the use of this data on any other system, nor does the fact of distribution constitute or imply any such warranty. Metadata_Reference_Information: Metadata_Date: 20030408 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Nora Shew Contact_Address: Address_Type: mailing and physical address Address: 4200 University Drive City: Anchorage State_or_Province: AK Postal_Code: 99508-4667 Country: USA Contact_Voice_Telephone: 907-561-1181 Contact_Electronic_Mail_Address: nshew@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998