Evidence for Late Cretaceous (Late Turonian) climate cooling from oxygen-isotope variations and palaeobiogeographic changes in Western and Central Europe

Trends of stable oxygen-isotope data through four European sections of Middle-Upper Turonian sediments show three phases of synchronous variations, each phase having a duration of about 250 ka. The isotopic variations are independent of local facies, sedimentary thickness and diagenetic history. Two positive delta(18)O shifts are associated with a southward spread of northern macrofaunas. This coincidence of geochemical and palaeontological data implies that the delta(18)O trends reflect a southward shift of cooler water masses. This southward extension of cooler waters was caused by changes in ocean circulation and was associated with a major regression in the early Late Turonian.