A BENTHIC FORAMINIFERAL RECORD OF PALEOCENE SEA-LEVEL AND TROPHIC REDOX CONDITIONS AT GEBEL-AWEINA, EGYPT/

We quantitatively analyzed benthic foraminiferal assemblages in order to reveal biotic and paleoenvironmental trends in the Paleocene sectio n of Gebel Aweina, Egypt, on the southern Tethyan shelf. The first cor respondence axis ranks taxa along an empirically derived bathymetric g radient, with neritic taxa (e.g., Discorbis duwi and Haplophragmoides walteri) opposed to bathyal taxa (e.g., Nuttallides truempyi and Gavel inella beccariiformis). The estimated paleodepth, as reflected by the various assemblages, was mostly similar to 200 m, but varied between s imilar to 50 m (P3a, NP4) and similar to 300 m (P4, NP8). The resultan t four relative sea-level cycles appear to be at least of regional ext ent and may in part be eustatically controlled. The second corresponde nce axis reflects trends in trophic and redox development. Low-food, h igh-oxygen conditions prevailed during Biochrons P1c-P3b (NP4-NP5) and late P4 (NP8), when assemblages were mostly dominated by Cibicidoides spp. Most oligotrophic conditions coincided with maximum paleodepth. Intermediate trophic levels were established during middle P4 (NP6) an d early P5 (NP9). From the level of the latest Paleocene benthic extin ction event (BEE; middle P5 and NP9) onwards until Biochron P6a (NP10) , assemblages dominated by buliminids marked increased trophic levels and reduced ventilation, probably resulting from enhanced surface prod uctivity. Enhanced surface productivity along the southern Tethyan mar gin started during Biochron P4, and, at least on some shelves, intensi fied after the BEE. Increasing productivity during the latest Paleocen e contrasts with global trends. This may be expected Curing climatic w arming and an expanding trophic resource continuum, leading to regiona lly intensified eutrophy and oligotrophy. High productivity through up welling along the southern Tethyan provides support for GCM prediction s of intense wind-stress in this region during the warm late to latest Paleocene. (C) 1998 Elsevier Science B.V.