Thermoluminescence dating of the Ryukyu Limestone

Thermoluminescence [TL] dating of calcite is useful for corals in the Pleis tocene Ryukyu Limestone in Okinawa Island, in which no aragonite is found. Fossil calcite corals in the Ryukyu Limestone have a variety of induced TL glow curves with peaks at about 150, 210, 250 and 310 degreesC. The TL grow th of a group of them exhibits supralinear behavior, while that of another group exhibits saturation behavior. Almost all of the TL ages of the corals which show the supralinear behavior are roughly consistent with ages estim ated from geology and uranium-series and ESR ages. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.