Bleaching of ESR signals by the sunlight:: a laboratory experiment for establishing the ESR dating of sediments

A laboratory bleaching experiment was performed in order to improve the method of ESR dating of sediments. Several sedimentary, volcanic, and granitic quartz samples showed consistent bleaching response for the exposure to halogen lamps. it was found that the most sensitive signals are the TI-H and Ti-Na centers. There was no difference observed within the samples exposed to light filtered by several color glass plates, according to the present preliminary result. (C) 2000 Elsevier Science Ltd. All rights reserved.