Mineralogy of Ypresian/Lutetian boundary at Fortuna (Murcia)

The Fortuna section has been studied in order to select a suitable section in Spain that could be a good candidate to define the Ypresian/Lutetian boundary stratotype. At present, this section is the most suitable, mainly because it is a complete marine section, well exposed and very rich in microfossils. A variation of mineralogical composition on the clays coincides with the most important change in planktonic foraminifera across the Y/L boundary. At this location, the data allowed us to infer a transgressive event associated with important hot and wet climatic changes that are the origin of an alteration and neoformation processes of clay minerals