Serpentinized peridotites recovered via oceanic drilling from the Atlantic Ocean subseafloor

Serpentinization is the water driven alteration of olivine-rich rocks which is a fundamental process that contributes to planetary habitability and the maintenance of rock-based life on Earth. This process leads to the formation of magnetite, which controls the magnetic properties of serpentinites. Several studies have suggested that serpentinization is accompanied by an increase in magnetization and decrease in rock density, which are linked to increasing porosity content. To investigate the potential correlation between porosity generation and serpentinization, we produced an analytical dataset that spans the geochemical composition, Fe redox state, and porosity of 28 abyssal serpentinites. These samples were recovered from the subseafloor of the Atlantic Ocean via oceanic drilling by international efforts of the Deep Sea Drilling Project (DSDP), Ocean Drilling Program (ODP) and International Ocean Discovery Program (IODP). The samples were recovered in proximity of the Mid-Atlantic Ridge (DSDP 109, ODP 209, IODP 304, IODP 357) and at a continent-ocean transition zone (ODP 173). The samples were recovered at depths ranging from few meters below the seafloor (DSDP 109, IODP 357), intermediate depths (ODP 209, IODP 304), to almost one km depth below the seafloor (ODP 173). The bulk compositions were analyzed by means of Fusion XRF, the water content and LOI via gravimetric methods, the reduced iron content via titration, and the porosity content via He-pycnometry.

蛇纹石化作用（Serpentinization）是富橄榄岩（olivine-rich rocks）在水驱动下发生的蚀变过程，它是支撑行星宜居性（planetary habitability）及维持地球岩生生命（rock-based life）的基础过程。该过程会形成磁铁矿（magnetite），而磁铁矿调控着蛇纹岩（serpentinites）的磁学性质。多项研究表明，蛇纹石化作用伴随磁化强度升高与岩石密度降低，这两者均与孔隙度（porosity content）增加相关。为探究孔隙生成与蛇纹石化作用之间的潜在关联，我们构建了一个分析数据集，涵盖28个深海蛇纹岩的地球化学组成、铁氧化还原状态及孔隙度。这些样品由深海钻探计划（Deep Sea Drilling Project, DSDP）、大洋钻探计划（Ocean Drilling Program, ODP）及国际大洋发现计划（International Ocean Discovery Program, IODP）通过国际合作大洋钻探，从大西洋海底以下获取。样品采集于大西洋中脊（Mid-Atlantic Ridge）附近（DSDP 109、ODP 209、IODP 304、IODP 357）及陆洋过渡带（continent-ocean transition zone）（ODP 173）。样品采集深度从海底以下数米（DSDP 109、IODP 357）、中等深度（ODP 209、IODP 304）到海底以下近1千米（ODP 173）不等。全岩组成通过熔融X射线荧光光谱法（Fusion XRF）分析，含水量与烧失量（Loss on Ignition, LOI）通过重量法测定，还原铁含量通过滴定法分析，孔隙度通过氦比重瓶法（He-pycnometry）测定。