Radiometric dates from Alaska: A 1975 compilation

The following table of radiometric dates from Alaska includes published material through 1972 as well as some selected later data. The table includes 726 mineral and whole-rock dates determined by the K-Ar, Rb-Sr, fission-track U-Pb, and Pb-alpha techniques.

The data are organized in alphabetical order of the 1:250,000 scale quadrangles in which the dated rocks are located. The latitude and longitude of each sample are given. In addition, each sample is located on a 1:250,000 quadrangle map by a grid system. The initial point of the grid is taken as the southwest corner of the quadrangle and the location of the sample is measured in inches east and inches north from that corner, e.g., "156E 126N" indicated 15.6 inches east and 12.6 inches north of the southwest corner of the quadrangle. Zeroes in the location columns for some dates indicate that accurate locations are not available.

Rock type, dating method, mineral dated, radiometric age, sample identification number, and reference are also listed where possible. Short comments, mostly geographic locality names, are given for some dates. These comments have been taken from the original references.

Sample identification numbers beginning with "AA" or "BB" have been assigned arbitrarily in cases where sample numbers were not assigned in the original references. Abbreviations are explained in the appendix at the end of table 1.