在海洋高营养低叶绿素地区（HNLC），沙漠释放矿物尘中的微量元素扮演重要的角色，进而影响全球碳循环（调节CO2 浓度和气候）。本项目通过对亚洲潜在尘源区远距离传输的粘粒中的粘土矿物、铁形态定量分布、铁同位素δ56Fe 和Sr-Nd-Hf同位素地球化学研究，查明亚洲尘源区无定形铁、铁氧化物、酸可溶粘土矿物和抗酸溶粘土矿物中铁元素在粘粒中赋存微观机制及铁同位素δ56Fe在不同矿物相的组成特征、不同沙漠粘粒铁形态的空间变化特点及其控制因素，进而估算亚洲矿物尘中可溶性铁及生物可利用性铁的贡献量。本项目的研究目的为全面评估亚洲尘对海洋初级生产力和影响全球变化贡献提供量化依据和消除因潜在亚洲尘可利用铁和生物可利用铁形态不确定性引起的争议。

Long-range transported mineral dust from deserts is potentially an important source of micronutrient iron, which has been shown to be the main limitation factor for phytoplankton growth in the High Nutrient Low Chlorophyll (HNLC) areas. Soluble iron in seawater depend on dust mineralogy, particle sized, atmospheric processes and cloud chemistry. The contribution of clays represents more than 96% of the total dissolved iron, despite their low iron content but thanks to their high iron solubility. The clay-sized fractions are a key source of the bioavailable iron in the open oceanic iron cycle, and play an important role of chemical heterogeneity in global iron cycle and influences particularly the global carbon cycle (mitigating the warming caused by rising levels of carbon dioxide). The aim of this study was to clay minerals, iron oxides, and their iron chemical speciations (ie. amorphous iron, crystalline iron oxides, acid soluble iron, refractory iron) in Chinese deserts in order to understand the controlling mechanisms on iron speciation and to eliminate uncertainties from dust provenance by caly-sized Sr-Nd-Hf isotopic composition and mineralogical iron species with iron isotopic technique. This study will provide valuable dataset to interdisciplinary research as marine and/or atmospheric chemistry, sedimentology and environmental sciences in the dust-climate-ocean system. Both new data and new geochemical tracer are conducive not only to understand atmospheric deposition of iron solubility to the open ocean but also to provide insight into evaluating iron weathering processes and the continentally-derived iron fluxes within the biogeochemical iron cycle.