沉积物的持续俯冲不仅影响了大陆地壳的演化和富集地幔的形成，其富集的微量元素（如LILE）和挥发分（如C、S和N）还制约着俯冲带元素循环、岛弧岩浆地球化学和同位素组成、以及相关金属矿床的形成。沉积物是俯冲板片中最富硫的层位，然而目前对俯冲沉积物中含硫矿物的岩石学和地球化学特征的研究匮乏，严重制约了对俯冲带硫循环的认识。本项目拟选取代表不同俯冲深度的美国Catalina片岩体、希腊Cycladic蓝片岩带以及我国阿克牙孜高压-超高压变质带为研究对象，对其中广泛产出的变质沉积岩中的含硫相（如硫化物和硫酸盐矿物等）进行详细的岩相学对比研究，查明俯冲过程中硫的变质演化特征；利用全岩和原位硫同位素等测试手段，确定俯冲沉积物携带的硫地球化学和同位素信息。项目实施有助于加强对俯冲带中硫的性质的理解，建立俯冲带硫循环模型，明确俯冲带对岛弧的硫效应，研究成果对揭示弧下岛弧岩浆地球化学性质和成矿作用有重要意义。

The subduction of marine sediment regulates the continental growth and evolution, as well as the formation of enriched mantle. Sediment subduction, with enrichment of many trace elements (e.g. LILE) and volatiles (e.g. C, S and N), is also the primary control on subduction element recycling, geochemical characteristics and isotopic compositions of arc magmas, and formation of arc-related ore deposits. The sediment is the most sulfur-rich sequence in the subducting slab. However, understanding of subduction zone sulfur recycling is largely hampered since little is known of the nature and fate of sulfur-bearing minerals in subducted sediments. This project is devoted to promoting petrological and geochemical investigations of sulfide and sulfate minerals in the widespread metasediments in the Catalina Schist (California, USA), Cycladic blueschist belt (Syros and Tinos, Greece) and Akeyazi HP-UHP metamorphic belt (Xinjiang, China). It is aimed to reveal the metamorphic evolution of sulfur in subduction zones. Based on the petrographic observation, the bulk and in-situ sulfur isotope analyses will be performed to study the geochemical and isotopic compositions of subducted sediments. This study will be conductive to understanding the sulfur geochemistry in the subduction zones, reconstructing the framework of subduction sulfur recycling, revealing the slab-arc sulfur transition, and deciphering its implications on sub-arc geochemistry and arc metallogenesis.