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

瑞典深部钻探计划(SDDP)的一个组成部分“古生代同心撞击构造”(CISP)项目的框架内，将详细研究巴尔托斯卡迪亚奥陶系沉积盖层的物相、稳定同位素和海平面变化。拟议的项目将为盆地内和全球对比提供精确的地层控制，所研究的部分将作为气候档案，展示在冰室-温室过渡期间环境和动物群的剧烈变化。它们将涵盖地球历史上最大的动物群多样化事件之一(“大奥陶纪生物多样化事件”)的间隔时间。详细的微相和生物相分析、牙形刺磷灰石的氧同位素研究和碳同位素记录将有助于更好地理解在生命演化的这一戏剧性时期发生巨大辐射的驱动力。这包括建立复杂的食物网和生态系统，例如第一个高度多样化的后生动物珊瑚礁。该项目代表着研究后生动物生物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生物礁发育的主要高峰与降温和冰期有关的假设。

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.