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The sources of the May 1202 and November 1759, M 7.5 Near East earthquakes remain controversial, because their macroseismal areas coincide, straddling subparallel active faults in the Lebanese restraining bend. Paleoseismic trenching in the Yammouneh basin yields unambiguous evidence both for slip on the Yammouneh fault in the twelfth-thirteenth centuries and for the lack of a posterior event. This conclusion is supported by comparing the freshest visible fault scarps, which imply more recent slip on the Rachaiya-Serghaya system than on the Yammouneh fault. Our results suggest that the recurrence of an A.D. 1202-type earthquake might be due this century, as part of a sequence similar to that of A.D. 1033-1202, possibly heralded by the occurrence of the 1995 Mw 7.3 Aqaba earthquake. The seismic behavior of the Levant fault might thus be characterized by millennial periods of quiescence, separated by clusters of large earthquakes. Keywords: Lebanon, Levant fault, historical earthquakes, paleoseismology, event clustering.

Cosmogenic dating, using in situ 26Al and 10Be in quartz pebbles from alluvial terrace surfaces, constrains the late Holocene slip rate on the Xidatan segment of the Kunlun fault in northeastern Tibet. Two terrace risers offset by 24 [+ or -] 3 and 33 [+ or -] 4 m, having respective ages of 1788 [+ or -] 388 and 2914 [+ or -] 471 yr, imply a slip rate of 12.1 [+ or -] 2.6 mm/yr. The full range of ages obtained ([less than or equal to]22.8 k.y., most of them between 6.7 and 1.4 k.y.) confirm that terrace deposition and incision, hence landform evolution, are modulated by post-glacial climate change. Coupled with minimum offsets of 9-12 m, this slip rate implies that great earthquakes (M [approximately]8) with a recurrence time of 800-1000 yr, rupture the Kunlun fault near 94 [degrees] E.