Understanding geological time: An innovative fusion of diagenetic and cyclostratigraphic concepts to reconstruct sediment composition, deposition rate, and geological time spans

有节奏交替的碳酸盐岩岩性在其起源方面一直是激烈讨论的主题。它们经常被用作天文强迫气候变化的记录，尽管已经证明成岩作用可以增强或掩盖环境信号，甚至引入节律性。该项目的目的是仔细研究成岩作用如何影响原始的天文强迫沉积旋回，评估哪些沉积环境和年龄受到特别影响，并评估时间在天文强迫岩性旋回中的分布情况。为了实现这一目标，将采用两种新的成岩作用方法（基于地球化学的“向量长度法”）和旋回地层学方法（统计方法，“阿尔法法”），结合现有的成岩作用或旋回地层学解释，对不同水深、纬度和年龄的IODP岩心记录和露头记录进行分析。此外，将建立一个有节奏交替的碳酸盐岩岩性数据数据库，并用于实现项目目标。这种成岩作用和旋回地层学的结合是前所未有的，有可能测试这两种方法的界限，并改善沉积物组成、沉积速率和地质时间的重建。

Rhythmically alternating carbonate lithologies have been subject of intense discussion in terms of their origin. They are often used as a record of astronomically forced climate change, even though it has been shown that diagenesis can enhance or disguise the environmental signal, or even introduce rhythmicity. The aims of the project are to scrutinise how diagenesis affects original astronomically forced sedimentary cycles, to evaluate which depositional environments and ages are especially affected, and to evaluate how time is distributed within an astronomically forced lithological cycle. To achieve this, two new methods from diagenesis (based on the geochemistry, "vector length methode") and cyclostratigraphy (statistical method, "alpha method") will be applied to different records from IODP cores and outcrop records from different water depths, latitudes and ages with existing interpretations on diagenesis or cyclostratigraphy. Further, a database with data on rhythmically alternating carbonate lithologies will be established and used to archieve the projects objectives. This combination of diagenesis and cyclostratigraphy is unprecedented and holds the potential to test the boundaries of both methods, and to improve the reconstruction of sediment composition, deposition rate and, as a consequence, geological time.