Isotopic interconnections in the earth system

拟议的研究计划的主要目标是使用总硫和氧同位素的尖端测量来跟踪“电子通过时间”。氧化还原转变，以及相关的电子流动，将固体地球与其流体外壳的共同演化联系起来。全球生物群介导了大部分这些转变，使地球表面环境的氧化还原轨迹被解释为生物进化的记录。在麦吉尔大学地球与行星科学系的稳定同位素实验室，我们使用实验室实验和对约束良好的现代环境的研究来校准古氧化还原变化的硫和氧同位素示踪剂。一旦校准，这些示踪剂，然后适用于从岩石记录的良好特性的样本集。例如，即将开展的工作的重点将从现代甲烷水合物的地球化学循环到岩浆脱气的活塞-圆筒调查。一个共同的主题将是提取硫和氧分馏的因素，在这些环境中的材料循环的特点。在进行实验室调查的同时，实地研究将涵盖地球历史的各个方面，从火山爆发的最新产物到地球上最古老的岩石（Nuvvuagittuq绿岩带）。这项工作的成功完成将为地球系统科学领域带来双重好处。首先，同位素示踪剂的氧化还原转换的校准将提供一个

The broad objective of the proposed research program is to track 'electrons through time' using cutting-edge measurements of total sulfur and oxygen isotopes. Redox transformations, and the associated flow of electrons, link the co-evolution of the solid earth and its fluid envelope. The global biota mediate most of these transformations, enabling the redox trajectory of the earth surface environment to be interpreted as a record of biotic evolution. In the stable isotope laboratory of McGill University's Earth and Planetary Sciences department, we use laboratory experiments and studies of well-constrained modern environments to calibrate sulfur and oxygen isotopic tracers of paleoredox changes. Once calibrated, these tracers are then applied to well-characterized sample sets from the rock record. The focus of upcoming work, for example, will range from biogeochemical cycling in modern methane hydrates to piston-cylinder investigations on magmatic degassing. A common theme will be the extraction of sulfur and oxygen fractionation factors that characterize material cycling in these environments. Concurrent with laboratory investigations, field studies will span the full range of Earth history, from the recent products of volcanic eruptions to some of the oldest rocks of Earth (the Nuvvuagittuq greenstone belt). Successful completion of this work will provide a double benefit to the field of Earth System Science. First, the calibration of isotopic tracers for redox transformations will provide a