Mineral Resources On-Line Spatial Data
Interactive maps > Data download > K/Ar ages from the National Geochronological Database
| Sample identification | ||
|---|---|---|
| ID | Unique record identifier | |
| RECNO | Unique NGDB identifier for sample. Multiple analyses on a single sample have the same Record Number. | |
| Geographic location | ||
| LATITUDE | latitude in decimal degrees | |
| LATDIR | Direction of latitude | |
| LONGITUDE | longitude in decimal degrees | |
| LONGDIR | Direction of Longitude | |
| ST | Two letter abbreviation for State sample was collected from | |
| Processing information | ||
| ANALYSISTY | Method of K/Ar dating | |
| AGECOMMENT | Informative text about the estimated age or the material analyzed | |
| DECCON | Potassium decay contants used in age calculation | |
| REFCODE | NGDB coded value linking radiometric date with published reference | |
| REFERENCE | Reference which is the source of the analytical information | |
| Sample characteristics | ||
| ROCKNAME | Rock type from which the dating sample is from | |
| MINERAL | Mineral or phase dated | |
| Analytic result | ||
| AGE | Age of sample in millions of years (m.y.) | |
| ERROR | Analytical error of calculated age | |
| K2OPCT | percent K20 | |
| AR40MOL | radiogenic 40Ar expressed as mol/gm scaled by 1.0E-10 | |
| ARRADPCT | Percent radiogenic Ar | |
| PRECISION_ | Description of location precision | |
U.S. Department of the Interior |
U.S. Geological Survey
URL: http://tin.er.usgs.gov/karage/about.php
Page Contact Information: pschweitzer@usgs.gov
Page Last modified: 11:37 on 20-Dec-2007
