Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2002 Title: K/Ar ages from the National Geochronological Data Base Edition: version 1.0 Geospatial_Data_Presentation_Form: tabular digital data Larger_Work_Citation: Citation_Information: Originator: Zartman, Robert. E. Originator: Bush, Charles. A. Originator: Abston Carl Title: National geochronological and natural radioelement data bases Publication_Date: 1995 Series_Information: Series_Name: U.S. Geological Survey Digital Data Series Issue_Identification: DDS-14 Online_Linkage: http://edc.usgs.gov/glis/hyper/guide/ngdb Description: Abstract: This data set, dds14kar, is a subset of the National Geochronological Data Base (NGDB), as published in 1995. It shows the distribution of published K/Ar and Ar/Ar age determinations in the United States. Sample location, rock description, analytical data, age, interpretation, and literature citation is given for each record. Purpose: This GIS representation of the data set facilitates the presentation and analysis of earth-science data. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 1995 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: 177.5 East_Bounding_Coordinate: -67.1 North_Bounding_Coordinate: 71.0 South_Bounding_Coordinate: 25.3 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: K/Ar geochronology Theme_Keyword: Ar/Ar geochronology Theme_Keyword: radiometric age Theme_Keyword: geochronology Place: Place_Keyword_Thesaurus: None Place_Keyword: US Place_Keyword: United States of America 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 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 National Geochronological data base is maintained by the U.S. Geological Survey. It was published by Robert E. Zartman, Charles A. Bush, and Carl Abston in 1995. The K/Ar and Ar/Ar portion of the data base was prepared for by Nora Shew and Tom Kress. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The radiometric ages are given in m.y., millions of years. The analytical error, also given in m.y., is listed for most ages. The numerical precision was not maintained during the data conversion and the user should be aware that more precision may be indicated than is real. Users should use this data set to learn about existing data, then research the original references to gain more information about the sample, analysis, and interpretation. Logical_Consistency_Report: This is a point data set, where each point represents a published analytical age determination. If an age is published in multiple references, it is represented as a single point and only a single reference is cited. Completeness_Report: This data set contains a subset of the National Geochronological data base, NGDB. Data for samples dated by a potassium-argon dating method and include location information are given here. The data set does not include the following dating methods: fission track, lead alpha, rubidium-strontium, samarium-neodymium, or uranium-thorium-lead. In addition, many fields associated with the K/Ar and Ar/Ar records were not included. Some of the missing fields are: analysis number, lab number, suite number, mineral code, county, quadrangle, scale, source, geo unit, petrographic code, lab code, and lexicon age. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The precision of the latitude and longitude values was not maintained during the data conversion and the user should be aware that more precision may be indicated than is real. The text field 'Precision' describes the positional accuracy of each point. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Zartman, Robert E. Originator: Bush, Charles A. Originator: Abston, Carl Publication_Date: 1995 Title: National Geochronological Data Base Geospatial_Data_Presentation_Form: tabular digital data Series_Information: Series_Name: U.S. Geological Survey Digital Data Series Issue_Identification: DDS-14A Type_of_Source_Media: CD-ROM Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 1995 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: DDS-14A Source_Contribution: The entire data set was obtained from DDS-14A. Process_Step: Process_Description: The National Geochronologic data base (NGDB) is stored in a relational data base program. DDS-14A published the data as a relational data base and separate ASCII format. The comma seperated value files were imported into database software, Access, where the table relationships were re-built. It was necessary to edit some records in order for the data base to be re-built. The actual data values were not changed. Once the Access data base was completed, select fields were used to build a DBF file. Using ArcView a shapefile was produced called dds14_k_ar_age.shp Process_Date: 2001 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: .002 Longitude_Resolution: .002 Geographic_Coordinate_Units: Decimal degrees Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: points Entity_Type_Definition: Rock or mineral sample dated by K/Ar geochronology Attribute: Attribute_Label: Recno (Record Number) Attribute_Definition: Unique NGDB identifier for sample. Multiple analyses on a single sample have the same Record Number. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 3 Range_Domain_Maximum: 18332 Attribute: Attribute_Label: Rockname (Rock) Attribute_Definition: Rock type from which the dating sample is from Attribute_Domain_Values: Unrepresentable_Domain: descriptive text of mixed case Attribute: Attribute_Label: Mineral Attribute_Definition: Mineral or phase dated Attribute_Domain_Values: Unrepresentable_Domain: descriptive text of mixed case Attribute: Attribute_Label: Age Attribute_Definition: Age of sample in millions of years (m.y.) Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -0.09 Range_Domain_Maximum: 6883 Attribute_Units_of_Measure: m.y. (million years) Attribute: Attribute_Label: Error Attribute_Definition: Analytical error of calculated age Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 940 Attribute_Units_of_Measure: m.y. (million years) Attribute: Attribute_Label: Analysisty Attribute_Definition: Method of K/Ar dating Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: (no value) Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 37Ar-41Ar total fusion Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 39Ar-40Ar incremental (plateau) Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 39Ar-40Ar total fusion Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 40Ar-40K isochron Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 40Ar/36Ar-40K/36Ar isochron Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Conventional K-Ar Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Conventional Rb-Sr (assumed initial 87Sr/86Sr) Enumerated_Domain_Value_Definition: Attribute: Attribute_Label: Agecomment Attribute_Definition: Informative text about the estimated age or the material analyzed Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: (no value) Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age meaning uncertain (analysis questionable) Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age meaning uncertain (geologic factors) Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age not evaluated Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age of intrusion Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age of later metamorphism Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age of metamorphic crystallization Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age of sedimentation Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age of uplift and cooling Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age of volcanism Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: age reset by thermal event Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: anomalous initial isotopic composition, age questionable Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: initial age disturbed by later metamorphism Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: initial age disturbed by weathering Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: maximum age of intrusion Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: maximum age of metamorphic crystallization Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: maximum age of volcanism Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: may denote delayed cooling Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: minimum age of intrusion Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: minimum age of metamorphic crystallization Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: minimum age of mineralization Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: minimum age of volcanism Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: sample contains excess radiogenic argon, age is too old Enumerated_Domain_Value_Definition: Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: sample contains inherited material, age is too old Enumerated_Domain_Value_Definition: Attribute: Attribute_Label: K2Opct Attribute_Definition: percent K20 Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 64 Attribute_Units_of_Measure: percent Attribute: Attribute_Label: Ar40mol Attribute_Definition: radiogenic 40Ar expressed as mol/gm scaled by 1.0E-10 Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.000000 Range_Domain_Maximum: 2453.000000 Attribute_Units_of_Measure: mol/gm Attribute: Attribute_Label: Arradpct (Arrad%) Attribute_Definition: Percent radiogenic Ar Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 100 Attribute_Units_of_Measure: percent Attribute: Attribute_Label: Deccon (Decay constant) Attribute_Definition: Potassium decay contants used in age calculation Attribute_Domain_Values: Unrepresentable_Domain: text Attribute: Attribute_Label: Latitude Attribute_Definition: latitude in decimal degrees Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 26.67 Range_Domain_Maximum: 71.0 Attribute_Units_of_Measure: degree 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: Longitude Attribute_Definition: longitude in decimal degrees Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -67.1 Range_Domain_Maximum: 177.5 Attribute_Units_of_Measure: degree Attribute: Attribute_Label: Longdir 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: St (State) Attribute_Definition: Two letter abbreviation for State sample was collected from Attribute_Domain_Values: Codeset_Domain: Codeset_Name: Two-letter abbreviations for US states Codeset_Source: USPS Attribute: Attribute_Label: Precision Attribute_Definition: Description of location precision Attribute_Domain_Values: Unrepresentable_Domain: descriptive text Attribute: Attribute_Label: Refcode Attribute_Definition: NGDB coded value linking radiometric date with published reference Attribute: Attribute_Label: Reference Attribute_Definition: Reference which is the source of the analytical information Attribute_Domain_Values: Unrepresentable_Domain: bibliographic citation 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: dds14k_ar_age.shp Distribution_Liability: The U.S. Geological Survey (USGS) provides this point data "as is." The USGS makes 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 been 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 distribuiton constitute or imply any such warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ESRI shapefile Format_Version_Number: 1.0 Format_Information_Content: Sample locations and age information File_Decompression_Technique: unzip Transfer_Size: 1 megabyte Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://tin.er.usgs.gov/karage/karage.zip Fees: none Metadata_Reference_Information: Metadata_Date: 20020123 Metadata_Review_Date: 20030303 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