Disentangling the impact of global and regional climate changes during the middle Eocene in the Hampshire Basin: new insights from carbonate clumped isotopes and ostracod assemblages

We present a novel multiproxy data set (bulk and clumped isotopes on gastropod shells variations in ostracod assemblages) of the Hampshire Basin (Southern-England) that sheds light connection between North Sea Atlantic Ocean through English Channel during deposition Barton clay formation (latest Lutetian—Bartonian, middle Eocene; ∼41–40 Ma). During this time period, operated as gateway warmer colder waters. High-latitude water mixing combined with regional hydrological cycle sea-level variations, may have contributed to mitigate temperatures Basin, an average recorded ca. 25°C. In uppermost part section two masses was limited or absent evidenced by (up 35°C) Basin. The large differences oxygen isotope composition seawater (δ18Owater) (from δ18Owater −1.7‰ −0.7‰) salinity Sea. Ostracods suggest temporary those caused relative variations. This scenario could be partially linked glacio-eustatic changes related climate fluctuations probably associated MECO event.