西太平洋暖池8.5Ma以来风尘输入变化及其古气候效应

风尘是西太平洋暖池区重要沉积组分之一，蕴含着长时间尺度全球气候变化的关键信息，然而目前仍缺乏系统研究。本项目以IODP363航次在西太平洋暖池采集的高质量岩芯（U1490）为主要研究对象，通过碎屑沉积物粒度、黏土矿物、Sr-Nd同位素等的综合分析，并与与暖池边缘和可能风尘源区（亚洲内陆沙漠和戈壁，以及澳洲和美洲大陆）等进行对比分析，对8.5Ma以来暖池区风尘来源进行系统研究。通过对风尘粒度和风尘通量等古气候示踪指标的研究，重建晚中新世以来风尘输入西太平洋暖池的历史，揭示主要环境和气候转折期（如青藏高原隆升、西南极冰盖形成、北半球冰盖形成和中更新世气候转型等）风尘通量的变化规律。依据风尘源区和风尘通量的变化，研究ITCZ的迁移历史。通过风尘通量与古生产力之间关系的研究，探讨风尘输入在气候变化中的作用。该项研究为深入研究晚中新世以来气候变化规律和驱动机制，以及未来气候预测提供了新的思路。

Eolian dust, as an important deposition in western Pacific warm pool (WPWP), carry key information on the regional and global climate change, however, study on the long-time scale eolian dust record of the WPWP is still absent. This proposal is designed to study a high-quality core samples (U1490) recovered from the core area of WPWP during IODP Expedition 363. The eolian dust provenance over the last 8.5 Ma will be traced based on the comprehensive provenance proxies, such as grain size, clay minerals, radiogenic Sr and Nd isotopes, by comparison among the different locations of the WPWP and the potential sediment source (Asian continent, American and Australia continent). In accordance with paleoclimate proxies, such as grain size and flux of eolian dust, we try to rebuild the input history of eolian dust in the WPWP, to disclose the variation of eolian dust flux during the major climate transitions (e.g. the uplift of Tibetan Plateau, west Antarctica ice-sheet build, Northern Hemisphere glaciation, and mid-Pleistocene climate transition). Based on the results of eolian dust source area and dust flux variations, we try to decipher the shift history of Intertropical Convergence Zone (ITCZ). According to the relationship between eolian dust flux and paleo-productivity, we try to discover the role of eolian dust on the global climate change since late Miocene. This study provide a new sight on the deeply understand on the Earth’s climate variation and driven mechanism, and provide theoretical support on the future climate prediction.