Geomorphic and paleoclimatic implications of latest Pleistocene radiocarbon dates from colluvium-mantled hollows, California.

Radiocarbon analyses of charcoal from basal colluvium in 11 California hollows show a clustering of dates between 9000 and 15 000 BP, an indication that changes in the storage and discharge of colluvium from hillslopes accompanied the Pleistocene-Holocene transition. One hypothesis is that greater storm intensities occurred in the latest Pleistocene and induced a higher frequency of landslides in hollows and a regional extension of channel heads upslope relative to the Holocene. The increased storage of debris during the Holocene may have resulted in a diminished supply of sediment to stream channels.-from AuthorsDept of Geology & Geophysics, Univ of California, Berkeley, CA 94720, USA.