Abstract: Waulsortian-Type Buildups in the Lower Carboniferous of the Bechar Basin, Northwestern Sahara of Algeria, North Africa

Abdelghani Setra

The carboniferous Waulsortian-type buildups within the Bechar basin occur in the lower group. They are exposed above the desert floor along a south to north-northwest-trending axis, with the younger buildups located to the south and the older ones to the north. These bioherms are apparently younger than those recognized in Europe and North America. These Algerian bioherms were initiated and persisted during the time interval represented by the conodont gnathodus bilineatus zone (lower Visean-upper Visean boundary). Although they are younger than their European and North American counterparts that are of Tournaisian-lower Visean age, these mounds appear to have formed in similar environmental and tectono-sedimentary conditions.

Their areal extent, geometry, and facies relationships suggest that they were limited to a shelf edge. Their deposition environments range from shallow marine to deep sea.

AAPG Search and Discovery Article #90980©1994 AAPG Southwest Section Meeting, Ruidoso, New Mexico, April 24-26, 1994