Dating of quaternary sediments from western Borneo, using optically stimulated luminescence

Optically Stimulated Luminescence (OSL) dates from five sites in western Ka limantan are compared with C-14 and thermo-luminescence dates from other se diments in the region. There is now strong evidence that the Old Alluvium o f Peninsular Malaysia is of late Pleistocene age and that it can be correla ted with the White Sand Complexes of western Borneo. This contrasts with th e late Pliocene to mid Pleistocene ages for Old Alluvium, based primarily o n stratigraphic deductions, put forward by geoscientists examining the regi onal tin deposits. This study shows that the upper parts, at least, of the western Borneo White Sand Complexes were deposited mid-way through the last glaciation (76 ka), with extensive terminal Pleistocene re-deposition (11. 2-9.8 ka) and at least two gully erosion events during the Holocene (5.8-3. 8 ka and 0.48 ka).