Ordovician climate change, sea level history and bioevents: the Baltoscandic record

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The Ordovician sedimentary cover of Baltoscandia will be investigated in detail for facies, stable isotope and sea-level changes in the frame of the project “Concentric Impact Structures in the Palaeozoic“ (CISP), an integral of the Swedish Deep Drilling Program (SDDP). The proposed project will provide precise stratigraphic control for intrabasinal and global correlations and studied sections will function as climate archives demonstrating drastic environmental and faunal changes during icehouse – greenhouse transitions. They will cover the interval of one of the biggest faunal diversification events in earth history (“Great Ordovician Biodiversification Event”). It is expected that detailed micro- and biofacies analysis, studies on oxygen isotopes from conodont apatite and the carbon isotope record will lead to a better understanding of the driving forces for the tremendous radiations during this dramatic interval in the evolution of life. This time includes the establishment of complex food webs and ecosystems such as the first highly diverse metazoan reefs. The project represents the opportunity to study metazoan reef growth versus changes in palaeoclimate and to proof or disproof the hypothesis that major peaks in Upper Ordovician biodiversity and reef development are connected to cooling and glacial periods.