The early middle Eocene transition at the Esera valley

An integrated study including magnetostratigraphy, larger benthic foraminifera and calcareous nannofossil biostratigraphy is presented herein. This work was performed in shallow marine siliciclastics rich foraminifera, around the Ypresian/Lutetian boundary Ésera valley (South-Central Pyrenees). Although content studied interval low, not allowing a precise Y/L to be recognised, taxa found are enough support chronostratigraphic attribution. Data obtained section has improved knowledge of (Nummulitesand Assilina) distribution through chron C21. SBZ 11 12 transition took place at lowermost C21r, as shown previous works. assemblages extend into C21n, where 13 occurs. These data, siliciclastic facies, with situ fauna, results shift 12/SBZ Lower Lutetian, younger than previously believed. Accordingly, occurs 12.