Seasonality and interannual climate variability during the Late Miocene: Testing and tuning climate models using oxygen isotope stratigraphy, growth increment analysis and new ground data

中新世浅水碳酸盐岩由于其地层记录中存在大量的间断，一般认为不适合于古气候分析。然而，珊瑚的硬年代学记录记录了大气的变化-这是中新世古气候学迄今未知的一个方面。在碎屑岩中发现了硬年代学所需的原始保存状态的硬石（Tortonian/Messinian年龄，Krousonas地区，克里特岛中部; Br 1153/7）。因此，基于这些平台周围沉积物的多尺度氧同位素分析有可能跟踪气候变率的年度，十年和千年的时间尺度上响应的日照强迫和干旱化的地中海地区在晚中新世的过程中。将在克里特岛中部（Phaibet地区）勘探其他露头。一个气候模型运行的基础上获得的一个单一的sclerochronical记录（为10马，中央克里特岛）在以前的项目（BR 1153/7）反映了真实的生物相分布superisingly好：比现在的温度在地中海温暖，在东大西洋的温度较低。预测的晚中新世温度和变异离子东大西洋将使用经典的生物相方法沿着Macronesian横断面（亚速尔群岛，马德拉群岛，加那利群岛和佛得角群岛）进行测试。仔细的古生物学分析将提供有关长期气候变化的信息，以及在地中海地区生态扰动期间热带生物群潜在避难所的位置。

Miocene shallow water carbonates are generally considered indaequate for palaeoclimatic analyses, because their stratigraphic record is punctuated by abundant gaps. However, sclerochronological records of corals document atmospheric variability - an spect hitherto unknown to Miocene palaeoclimatology. Skeletons in a pristine state of preservation required for sclerochronology have been detected in debrites intercalated with rhythmically stratified deep-water clay and marl (Tortonian/Messinian age, Krousonas area, Central Crete; Br 1153/7). A multi scale oxygen isotope analysis of based on these periplatform sediments therfore has the potential to track climate variability on annual, decadal and millennial timescale in response to insolation forcing and aridisation of the Mediterranean area over the course of the Late Miocene. Additional outcrops will be explored in Central Crete (Phaistos area). A climate model run based on a single sclerochronological record (for 10 Ma, Central Crete) obtained during a previous project (BR 1153/7) reflects real biofacies distributions superisingly well: warmer than present temperatures in the Mediterranean, and colder temperatures in the E Atlantic. Predicted Late Miocene temperatures and variability ion the E Atlantic will be tested using the classical biofacies approach along the Macronesian transsect (Azores, Madeira, Canary and Cape Verde Islands). Careful palaeontological analysis will provide information regarding long-term climate changes and the location of potential refugia for tropical biota during times of ecological perturbatins in the Mediterranean area.