Climatic and environmental changes documented in the upper Paleocene to lower Eocene of Egypt

In a multidisciplinary approach including biostratigraphy, sedimentology, mineralogy and geochemistry, we attempt to reconstruct climatic evolution and environmental changes in Egypt from the late Paleocene to the early Eocene, with a special attention to the Late Paleocene Thermal Maximum (LPTM). In this region, despite the presence of short hiatuses at the planktic foraminiferal subzone P5a/b boundary, the LPTM interval is marked by a major turnover in the calcareous nannofossils coincident with the first appearance of the characteristic short ranging LPTM species Acarinina sibalyaensis. This faunal turnover is accompanied by a negative delta(13)C shift, a decrease of calcite and an increase of detrital quartz and high kaolinite contents. During the early Paleocene (Zone P3), this region experienced a warm and humid climate with high rainfall as indicated by the abundance of kaolinite in marine sediments. Subsequently, in Zones P4 and P5 seasonal climatic conditions with alternating wet and dry seasons evolved in this region as indicated by the low kaolinite content and the abundance of smectite. During the LPTM, southern Egypt was affected by a humid and warm climatic episode which persisted through the early Eocene (Zone P6). The presence of condensed phosphates coincident with high organic matter just above the LPTM is consistent with an upwelling activity at this time.