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North Africa has undergone drastic climatic changes over the past several hundred thousand years, The timing of humid intervals called pluvials was investigated by uranium-series disequilibrium dating of travertines from the Kurkur Oasis. Western Desert. Egypt. The youngest and best dated travertines (70-160 ka) are found in Wadi Kurkur and include spring and lacustrine units exposed as 2 to 3 m high terraces. Travertines having an age of approximately 191-220 ka are exposed by differential erosion as linear mounds produced by spring systems over fracture zones in ancient wadis. The oldest travertines, having ages >260 ka, are extensive, cap limestone units above the oasis, and were deposited in paludal and lacustrine environments. Oxygen isotope ratios were measured for the wadi travertines (delta(18)O values ranging from 16.7 to 19.1 parts per thousand SMOW) and for spring mound travertines (18.5-20.5 parts per thousand). Equilibrium oxygen isotope fractionation calculations indicate that the Kurkur travertines were deposited from waters having delta(18)O values similar to ancient Western Desert groundwaters (similar to -11 parts per thousand, Sonntag er al., 1978a.b: Thorweithe, 1990: Sultan et al., 1996). The ages of the travertines correspond to times of monosonal maxima, eustatic sea level high stands and interglacial maxima. Rainfall producing these groundwaters (and travertines) was significantly fractionated during atmospheric transport, in contrast to modern meteoric waters (-2.09 parts per thousand, Joseph et al., 1992), implying a distant source for the pluvial waters. Increased precipitation, recharge of Western Desert groundwaters, and resultant travertine deposition are interpreted to be consequences of Milankovitch insolation cycle forcing, through enhanced Atlantic and Indian Ocean monsoons during interglacial time periods. (C) Elsevier Science B.V.