The Deep Sulfur Cycle in Subduction Zones and Arc Magmas

俯冲带和弧岩浆中的深部硫循环

• 批准号: 1347085
• 负责人: Cin-Ty Lee
• 金额: $ 27.97万
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1347085&HistoricalAwards=false
• 关键词: Deep; Sulfur; Cycle; Subduction; Zones

Sulfur is a ubiquitous element on Earth. Because it exhibits a wide range of valence states, sulfur can behave as an electron acceptor or donor and thus is a potent driver of redox reactions, dictating the mobility of metals and serving as an energy source for life. Understanding sulfur geochemistry in the deep Earth is thus critical to understanding the origin of ore deposits, the evolution of oxygen in the atmosphere and marine environment, the pathways of biogeochemical processes, and climate change. As a small step towards better understanding the deep sulfur cycle, these researchers will characterize the sulfur content and isotopic composition of a volcanic arc, from the mantle through the crust.How sulfur cycles between the endogenic (crust, mantle, and core) and exogenic (ocean, atmosphere, and biosphere) Earth systems is of particular interest regarding the role of sulfur in various redox-driven processes on Earth. The locus of sulfur flux between these Earth systems occurs in volcanic arcs, where mantle melting in the subduction wedge induces shallow melting and ultimate storage or eruption of magma within or through the crust. The goal of this project is three-fold: 1) quantify how much sulfur and what type (sulfate vs. sulfide) is transported via the slab to depths of magma generation in subduction zones, 2) construct the ?stratigraphy? of sulfur from the mantle through the crust in volcanic arcs, and 3) define the average sulfur concentration of juvenile and mature continental crust. From this information the sulfur content and isotopic architecture of an arc from the mantle through the crust can be constructed, with implications for sulfur cycling between the endogenic and exogenic Earth systems.

硫是地球上普遍存在的元素。由于硫具有广泛的价态，因此它可以作为电子受体或供体，因此是氧化还原反应的有力驱动者，决定了金属的流动性并作为生命的能源。因此，了解地球深部的硫地球化学对于了解矿床的起源、大气和海洋环境中氧的演化、地球化学过程的途径以及气候变化至关重要。作为更好地理解深部硫循环的一小步，这些研究人员将描述火山弧从地幔到地壳的硫含量和同位素组成。硫在地球上各种氧化还原驱动过程中的作用特别令人感兴趣，因为硫在内生（地壳，地幔和地核）和外生（海洋，大气和生物圈）地球系统之间的循环如何。这些地球系统之间的硫通量的轨迹发生在火山弧中，在俯冲楔中的地幔熔融导致浅熔融和最终储存或岩浆在地壳内或通过地壳喷发。该项目的目标有三个方面：1）量化有多少硫和什么类型（硫酸盐与硫化物）通过板块输送到俯冲带岩浆生成的深度，2）构建？地层学？确定了新生陆壳和成熟陆壳的平均硫浓度。根据这些信息，可以构建从地幔到地壳的弧的硫含量和同位素结构，这对内生和外生地球系统之间的硫循环有影响。