C

Radiometrie dating method dependent on the decay of a minor isotope of calcium. The great potential of this method, which is as yet not developed sufficiently for reliable application, is that calcium is a major component of animal bone. The isotope ⁴¹Ca has a half-life of ca. 100 Kyr and would thus allow direct dating of specimens ranging in age from 10 Ka, or even less, to as much as 1 Ma. This range would extend the dating of Late and Middle Pleistocene archaeological and paleontological material beyond the current limits of radiocarbon, uranium-series, and trapped-charge methods, spanning the gap to the upper limits of typical K/Ar and Ar/Ar dating. There are, however, several major difficulties involved with this method, which, as of the late 1990s, had not been tested on ancient materials.