Microfaciès de croûtes calcaires et travertins de Sidi Bou Zid (Beni Iznassen, Maroc oriental)

The Oued Bou Zid lower valley demonstrates a recent model (Upper Pleistocene-Holocene) of laminar crusts with little modification by diagenesis and pedogenesis. The geologic sections and microscopic studies allow to study crust microfacies and their relationship with marshy land and freshwater travertines.They record a complex story, which is marked manly by several successive superficial and subsuperficial sedimentary deposits. Laminar crust are slope formations, whereas travertines characterize the bottom of the valley. There exist secondary penetration of crust in the travertines. However, both facies are not synchronous: they indicate periods of biogenic CaCO 3 accumulation over distinct morphoclimatic context.