Quantifying the bulk mineralogy of Arctic Ocean sediments of the last 80 Ma: Terrigenous sediment transport, climate and sediment deposition characteristics

本项目继续致力于北冰洋中部（AO）白垩纪至第四纪沉积物的全面定量相分析。正如广泛使用x射线衍射数据来测定岩性所表明的那样！它是国际协调的第四纪至白垩纪沉积物岩心研究的重要组成部分。目前，对230个粉末样品进行了x射线衍射研究，揭示了ACEX岩心的沉积和早期成岩历史。该研究项目的第二年旨在对最相关的沉积物序列进行更高分辨率的采样。ACEX岩心的初步地层结果表明，从大约15-16亿年前（中新世中期）到今天，存在连续的沉积作用。这是第一次提供了一个变化来解决北半球冰川增加的前所未有的细节，在大约88°n的记录中。潜在冰川区域的矿物指纹是众所周知的。因此，海冰和（或）冰山的沉积物运输可以被重建，早期冰川历史可以被清除。在晚白垩世/早第三纪温室和中第三纪冰窖沉积序列之间，矿物组合发生了强烈的变化。在这里，我们将试图解释是否只有构造原因（罗蒙诺索夫海脊的分离和淹没）或另外的震源区域变化是原因。

This project continues to aim on the full quantitative phase analysis (QPA) of Cretaceous to Quaternary sediments of the central Arctic Ocean (AO). As indicated by the extensive use of the X-ray diffraction data for the determination of lithologica! units of the IODP Leg 302-Arctic Coring Expedition (ACEX) cores it is an important part of the internationally coordinated investigation of the cored Quaternary to Cretaceous sediments. Currently, 230 powdered samples are investigated with Xray diffraction revealing the sedimentation and early diagenetic history of the ACEX cores. The second year of this research project aims on a higher resolution sampling of the most relevant sediment sequences. Initial stratigraphic results of the ACEX cores assume a continuous sedimentation from about 15-16 Mill, years ago (middle Miocene) to today. This provides for the first time the change to resolve the increasing glaciations of the Northern Hemisphere in unprecedented detail in a record from about 88° N. The mineralogical fingerprints of the potential glaciated regions are well known. As a result, sediment transport by sea ice and/ or icebergs are reconstructable and the early glaciation history can be cleared. The mineral assemblage has strongly changed between the late Cretaceous/ Early Tertiary Greenhouse and the middle Tertiary Icehouse sediment sequences. Here, we will try to decipher if only tectonic reasons (separation and drowning of the Lomonosov Ridge slide) or additionally source region change have been the reason.