sentences:  The age is considered to be latest Kimmeridigan to earliest Tithonian.The Assenta Member is around 300 metres thick and predominantly consists of mudstones with frequent layers of caliche.Near the top of the member several layers of tens of metres thick nodular and marly bioclastic limestones are present, containing marine benthic forams, the nodularity is derived from intense "Thalassinoides" burrowing.