A B S T R A C T : Clay mineral associations of Palaeocene and Eocene age, with special attention to the late Palaeocene thermal maximum, have been examined in ten sections from the Tethys (Egypt, Israel, Tunisia, Spain and Kazakhstan) and Atlantic (England). A widespread abundance of kaolinite in marine sediments at all locations suggests a warm and humid climate with high rainfall in the Tethys region during the early Palaeocene. In the coastal basins along the southern margin (Israel and southern Tunisia), kaolinite disappears gradually giving way to palygorskite and sepiolite, suggesting the progressive development of arid climatic conditions in this part of the Tethys from the late Palaeocene to the early Eocene. Remarkably, kaolinite increases strongly throughout most of the Tethys during the late Palaeocene thermal maximum (LPTM) reflecting an episode of humidity and warmth and coincident with a global maximum warmth of seawaters inferred from oxygen isotopic data.

We studied two sections that accumulated during the Paleocene±Eocene transition in shelf waters in the northeastern Tethys. Stable carbon isotopic compositions of marine and terrestrial biomarkers are consistent with a 13

During the early Palaeocene (zones P1 to P2), the southeastern Tethyan margin experienced a warm and humid climate with high rainfall as indicated by the abundance of kaolinite within marine sedimentary rocks. Subsequently, in Zone P2, arid climatic conditions evolved in the coastal basins of the southern Tethys margin as indicated by the gradual disappearance of kaolinite and the increased abundance of palygorskite and sepiolite. Arid climatic conditions persisted during the Selandian and Thanetian (late Palaeocene) and reached a maximum in the Ypresian (early Eocene). During the late Palaeocene thermal maximum, warm climatic conditions were associated with increased aridity and led to sea surface warming, though not bottom water warming, as suggested by the planktic 18 O excursion observed at the Zomet Telalim basin (Negev, Israel). Strongly reduced surface productivity accompanied by unusually light 13 C are associated with the late Palaeocene thermal maximum in the Negev as well as globally.