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

本项目的重点是研究现代和化石鞘总科(乌贼目、贝雷米特目)内部碳酸盐骨架的结构和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骼的地球化学成分在多大程度上受到古生物(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、自生学和成岩作用的界面。1.新乌贼属乌贼这表明热带和高纬度分类群的生长速度明显不同，这一因素也可能适用于白头翁属。不同的形态群可能有不同的个体发育，占据不同的栖息地。这一点应该反映在反映海水组成的地球化学信号中。2.温度和盐度似乎是控制贝伦石护卫器组成的主要物理因素。我们希望通过使用地球化学多指标方法(δ18O、δ13C、镁/钙)来明确区分这两个因素。3.将测试对信号解释至关重要的潜在成岩叠加。通过应用各种技术(扫描电子显微镜、阴极发光分析、EBSD、微探针、元素分析)对不同地貌类型的薄片进行分析，确定不同的成岩蚀变程度。

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.