Neogene transitional carbonates: the link between the tropical and the temperate carbonate province

水温是浅海碳酸盐岩形成的主要控制因素。在温暖的沃茨，发光动物协会占主导地位，而冷水区包含异源动物工厂。浅海碳酸盐的形成也取决于营养水平。高营养含量触发的生长的异源动物碳酸盐生产者，低营养水平的形成发光动物碳酸盐。在碳酸盐沉积体系的这些端员或多或少在最近和过去的地质已知的，非常少的数据和模型存在的过渡系统。本项目解决了这一点。将对撒丁岛早中新世至中中新世浅海温带至亚热带碳酸盐岩进行分析，以建立“中间”类型碳酸盐岩系统的模型。这种系统和真正的温暖和冷水存款之间的差异将被提出。沉积学、岩石学、成岩学和地球化学分析（稳定的氧和碳同位素）将显示这类碳酸盐沉积体系的动力学，作为对海平面波动和古海洋学波动的反应。浅海碳酸盐岩对环境变化的敏感性将被用来解释全球中新世气候演变如何影响这些沉积体系。

Water temperature is a major controlling factor for neritic carbonate production. In warm waters, the photozoan association dominates, whereas cool water zones contain the heterozoan factory. Neritic carbonate formation also depends on nutrient levels. High nutrient contents trigger growth of heterozoan carbonate producers, low nutrient levels the formation of photozoan carbonates. Where these end members of carbonate depositional systems are more or less known in the recent and in the geological past, very little data and models exist for transitional systems. This projet addresses this point. Early to middle Miocene neritic temperate to subtropical carbonates in Sardinia will be analyzed in order to develop models for an "intermediate" type of carbonate system. Differences between such systems and true warm and cool water deposits will be presented. Sedimentological, petrological, diagenetical and geochemical analyses (stable oxygen and carbon isotopes) will show the dynamics of this type of carbonate depositional system as a response to sea level fluctuations and palaeoceanographic fluctuations. The sensitivity of neritic carbonates to environmental change will be used to decipher how the global Miocene climatic evolution affected these depositional systems.