Geochronometer

Application of the K-Ca geochronometer therefore is best suited to minerals with high K/Ca ratios (Marshall & DePaolo, 1982) and K-bearing clay materials might appear to be amenable to its use.

Other geochronometers like ^{₈₇}Rb-\!^{₈₇}Sr, ^{₁₄₇}Sm-\!^{₁₄₃}Nd, or ^{₁₈₇}Re-\!^{₁₈₇}Os are also successfully applied to dating ore deposits and magmatic, metamorphic, or sedimentary processes.

K-bearing minerals such as biotite, sanidine, plagioclase, and hornblende are geochronometers representative of the time of their crystallization once they were erupted from a volcano, and then transported into marine sedimentary basins.