We have investigated the effects of annealing quartz at temperatures up to 1000 degreesC on both the absolute sensitivity and on the growth curve shape, using quartz extracts from three sedimentary samples from widely separated locations. Growth curves up to 670 Gy were measured using the single-aliquot regenerative-dose protocol, which allows all heat treatments and OSL measurements to be performed on a single sub-sample, with a corresponding improvement in precision when compared with multiple-aliquot protocols. It is found that the degree of dose-dependent sensitivity change is dependent on the annealing temperature. Despite this, and absolute sensitivity changes of more than three orders of magnitude, the growth-curve shape is relatively independent of annealing temperature, especially at low doses. (C) 2001 Elsevier Science Ltd. All rights reserved.