BENTHIC FORAMINIFERAL EXTINCTION AND REPOPULATION IN RESPONSE TO LATEST PALEOCENE TETHYAN ANOXIA

The latest Paleocene benthic foraminiferal extinction event has been s tudied in two marlstone successions in the Tethys: at Wadi Nukhl (Egyp t) and Torangly (Turkmenistan). Both sections yield a sapropelic layer at the level of the extinction event. At Nukhl, this layer underlies a thin calcareous bed that has also been found in other Middle East up per Paleocene sections. With the onset of anoxia at the Tethyan sea Bo or, the aerobic and oligotrophic Gavelinella beccariiformis deep-sea c ommunity collapsed. Eutrophic-to-mesotrophic and low-oxygen conditions , most likely resulting from enhanced organic carbon fluxes to the sea floor, triggered an similar to 100-200 k.y. repopulation sequence, ma rked by downslope migration of several neritic communities that were d ominated by opportunistic and tolerant taxa. The initial ecosystem res toration was completed when an aerobic and oligotrophic Nuttallides tr uempyi deep-sea community became established. We suggest that this rep opulation mode could be typical for the central Tethys.