Rubidium-strontium dating of ore deposits hosted by rubidium-rich rocks, using calcite and other common Sr-bearing minerals.

Applications of Rb/Sr dating on ore deposits using common gangue minerals are tested. The only conditions a deposit must meet are: 1) it should have minerals with a low Rb/Sr ratio, such as calcite and fluorite; 2) it should be enclosed by wall rock with a high Rb/Sr ratio. The Rb/Sr 'model ages', obtained for three hydrothermal ore deposits of different age, mineralogy, and geological setting agree well with those obtained by conventional K/Ar and Rb/Sr dating methods. The precision, however, can be poor and depends chiefly on the Sr isotope heterogeneity of the wall rock and its Rb/Sr enrichment. The approach presented here might be useful in dating fractures and faults filled with calcite and in deciphering the geological history of structurally complex areas.-L.-diH.