Paratethys-Southern Ocean teleconnection in the mid-Burdigalian: European climate on the verge to the Miocene Climate Optimum

The Early Ottnangian Cooling (EOC), a distinct cold-spell in European climate at ~18 Ma preceding the Miocene Climate Optimum, is frequently reported in Paratethys records; however, the duration, magnitude, and underlying causes are poorly understood. A new paleoclimatic data-set provides unexpected insights into this event. UK'37-based sea surface temperatures > 25°C between 18.6 and 17.7 Myrs substantially exceed existing estimates, and indicate a significantly warmer European climate than previously assumed for this usually poorly recovered time interval. The EOC is expressed as an average drop of 2-3°C in Paratethyan water temperatures between ~18.1 and 17.8 Myrs punctuated by two distinct cold snaps at ~17.86 Ma and ~17.81 Ma. The short duration of the EOC excludes Tethyan Seaway closure as its underlying cause. Instead, the revealed paleoclimatic pattern shows a strong correlation with isotope event Mi1b in deep-sea δ18O records (ODP Site 1090), and we propose a tight paleoclimatic coupling between the Southern Ocean and the Paratethys/Mediterranean realm as an alternative hypothesis. Eccentricity forcing most likely acted as pacemaker of this teleconnection, a mechanism recently emphasized in Early Miocene studies.