U/Th dating of a Quaternary travertine from southern Morocco: palaeoclimatic consequences during Middle and Upper Pleistocene

A large travertine outcrop south of Errachidia, southern Morocco, was studied and U/Th dated. The carbonate fraction was provided by groundwaters then, as now, from the eastern High Atlas percolating through the regional Infra-Cenomanian aquifer. There were two main periods of accumulation at ca 262 kyr BP and 20-11.5kyr BP separated by a long discontinuity with some limited weathering and erosion and correlated in part with a period of erosion at 30-20kyr BP further to the west. The two travertine-deposition periods suggest increased rainfall and/or cooler thermal conditions in the eastern High Atlas source regions. Massive travertine accumulation ceased at the end of the Upper Pleistocene. To cite this article: L.Boudad et al., C. R. Geoscience 335 (2003).