Stable isotope geochemistry of pore waters and marine sediments from the New Jersey shelf: Methane formation and fluid origin@en

Interstitial water and sediment samples of the Integrated Ocean Drilling Program (IODP) expedition 313 \"New Jersey Shallow Shelf\" were analyzed for chemical composition and stable isotope ratios. A total of 222 water samples were collected from the cores by Rhizon samplers and squeezing of fresh core material. Water was analyzed for its stable oxygen and hydrogen isotope geochemistry (d2H and d18O) at sites M0027A and M0029A, and the carbon isotope composition of the dissolved inorganic carbon (d13CDIC) (all sites). In addition, organic material (Corg) and inorganic carbonates from sediments were analyzed for their carbon ratios (d13Corg and d13Ccarb), and in case of the carbonates also for oxygen (d18Ocarb). Carbon isotopes were also analyzed in samples containing enough methane gas (d13Cmeth). Pore fluids from site M0027A were analyzed for the sulfur isotope composition of dissolved sulfate (d34S). The combination of isotope analyses of all phases (interstitial water, sediment, and gas) with pore water chemistry is expected to enable a better understanding of processes in the sediment and will help to identify the origin of fluids under the New Jersey shelf.本数据集针对综合大洋钻探计划（Integrated Ocean Drilling Program, IODP）第313航次“新泽西浅陆架”获取的间隙水与沉积物样品，开展了化学成分与稳定同位素比值分析。研究人员通过Rhizon采样器（Rhizon sampler）与新鲜岩芯挤压法，从岩芯中共计采集222份水样。在M0027A与M0029A站位，对水样开展稳定氧、氢同位素地球化学分析，测定其d2H与d18O值；同时在所有站位，分析了溶解无机碳的碳同位素组成（d13CDIC）。此外，针对沉积物中的有机质（Corg）与无机碳酸盐，研究人员测定了其碳同位素比值（d13Corg与d13Ccarb），其中碳酸盐样品额外开展了氧同位素分析（d18Ocarb）。对于甲烷含量充足的样品，同步开展了碳同位素分析（d13Cmeth）。针对M0027A站位的孔隙流体，研究人员还分析了溶解硫酸盐的硫同位素组成（d34S）。本研究将所有物相（间隙水、沉积物与气体）的同位素分析结果与孔隙水化学数据相结合，旨在深化对沉积物内部过程的认知，并助力厘清新泽西陆架下方流体的成因。