Sulfur biogeochemistry of pore waters and sediments from IODP Expedition 307

沉积物和孔隙水是现在和过去微生物活动的生物地球化学信号的载体。本项目涉及从含珊瑚的Challenger丘陵和周围沉积地点回收的沉积物的深层生物地球化学硫-铁循环中的成岩过程(IODP Expeiton 307)。我们将通过无机和稳定同位素、地球化学、孔隙水和固相研究来鉴定那些表征微生物硫转化的反应。该项目将重点研究孔隙水、硫酸盐和硫化物矿物的含量和硫、氧同位素组成以及铁的形态，以反映深埋海洋沉积物中的地质微生物反应历史。该项目还将探讨碳酸盐丘下面的中新世沉积物通过甲烷作为中间底物驱动深层生物圈正在进行的硫成岩作用的问题。

Sediments and pore waters are carriers of biogeochemical signals for present and past microbial activity. The present project deals with diagenetic processes in the deep biogeochemical sulfur-iron cycle of sediments recovered from the coral-bearing Challenger Mound and surrounding sedimentary sites (IODP Expediton 307). We will identify those reactions that characterize the microbial sulfur transformations by means of inorganic and stable isotope geochemical pore water and solid phase investigations. The project will focus on the potential of the contents and sulfur and oxygen isotopic composition of pore water sulfate and sulfide minerals as well as iron speciation to reflect the history of geomicrobial reactions in deeply buried marine sediments. The project will also address the question of the role of the Miocene sediments underlying the carbonate mound for driving ongoing sulfur diagenesis by a deep biosphere via methane as intermediate substrate.