CLIMATIC AND PALEOENVIRONMENTAL CHANGES DURING THE PALEOCENE- EOCENE THERMAL MAXIMUM: FROM MARINE TO CONTINENTAL ENVIRONMENTS
In India, the establishment of wetland conditions and related thick lignite accumulations reflect the response of the continental environments to the PETM. Biostratigraphy and carbon isotope analyses in three lignite mines located in NW India reveal the presence of both PETM and ETM2 organic carbon isotope negative excursions and demonstrate that modern mammals appeared in India after the PETM. Relative ages of this mammal event based bio-chemo- and paleomagnetic stratigraphy support a migration path originating from Asia into Europe and North America, followed later by a migration from Asia into India.
In contrast, at Esplugafreda, Spain, the terrestrial environment reacted differently; increased weathering due to enhanced runoff led to the formation thick paleosoils enriched with carbonate nodules (Microcodium like) suggesting a coeval semi-arid climate. High-resolution δ13C and δ18O analyses of two types of calcareous paleosoil nodules reveal two distinct negative δ13C excursions. But both δ13C excursions correspond to the PETM event, as the top of the upper δ13C excursion is of Ilerdian age. The lower δ13C negative excursion represents therefore a pre-PETM event, which represents an initial step, which may have triggered the PETM-CIE and could be linked to enhanced late Paleocene volcanic activity.