The carbonate skeleton of recent and fossil Coleoidea: Biological, physical or diagenetic control?

本项目主要研究近、古总总纲（棕褐色、角闪石）内部碳酸盐骨架的结构、功能及其地球化学信号。它旨在了解这些被地层学家、地球化学家和古气候学家广泛使用的骨架的地球化学组成在多大程度上受古生物(1)、物理(2)和/或成岩因素(3)的控制。因此，我们清楚地涵盖了生物学、天然气技术和成岩作用的界面。1. 近代乌贼科的海骨表明热带和高纬度分类群的生长速率有显著差异，这一因素也可能适用于菱形石。不同形态群的菱铁矿可能具有不同的个体发生，占据不同的生境。这应该反映在反映海水成分的地球化学信号中。2. 温度和盐度似乎是控制菱铁矿护石组成的主要物理因素。我们希望通过使用地球化学多代理方法（δ18O, δ13C, Mg/Ca）来明确区分这两个因素。3. 潜在的成岩叠印，对信号的解释至关重要，将被测试。通过应用各种技术（SEM，阴极发光分析，EBSD，显微探针，元素分析）对各种形态的薄片进行分析，可以确定不同程度的成岩蚀变。

This project focuses on the structure and function of internal carbonate skeletons of recent and fossil Coleoidea (Sepia, belemnites) and their geochemical signals. It aims at understanding to which extent the geochemical composition of these skeletons, widely used by stratigraphers, geochemists and palaeoclimatologists is controlled by palaeobiological (1), physical (2) and/or diagenetic factors (3). We thereby clearly cover the interface of biology, autecology and diagenesis. 1. Cuttlebones of recent Sepia spp. suggest significantly different growth rates for tropical and high latitudinal taxa, a factor that may apply for belemnites as well. Different morphological groups of belemnites may have had a different ontogeny, occupying different habitats. This should be mirrored in the geochemical signals reflecting the composition of the ocean water. 2. Temperature and salinity seem to be the main physical factors controlling the composition of the belemnite guards. We want to clearly differentiate between both factors by using a geochemical multi proxy approach (δ18O, δ13C, Mg/Ca). 3. Potential diagenetic overprint, crucial for the interpretation of the signals, will be tested. By applying various techniques (SEM, cathodoluminiscence analyses, EBSD, microprobe, elemental analyses) to thin sections of various morphotypes, differential degrees of diagenetic alteration should be defined.