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

在“古生代同心冲击结构”（CISP）项目框架下，Baltoscandia的奥陶系沉积盖层将详细研究相、稳定同位素和海平面变化，该项目是瑞典深钻计划（SDDP）的一部分。拟议的项目将为盆地内和全球相关性提供精确的地层控制，所研究的剖面将作为气候档案，展示冰窖-温室过渡期间剧烈的环境和动物变化。它们将涵盖地球历史上最大的动物多样性事件之一（“奥陶纪生物多样性大事件”）。详细的微相和生物相分析、牙形石磷灰石的氧同位素研究和碳同位素记录将有助于更好地了解在这一生命演化的戏剧性时期产生巨大辐射的驱动力。这段时间包括建立复杂的食物网和生态系统，如第一个高度多样化的后生动物珊瑚礁。该项目提供了研究后生动物珊瑚礁生长与古气候变化的机会，并证明或反驳了上奥陶统生物多样性和珊瑚礁发育的主要高峰与冷却期和冰川期有关的假设。

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.