IODP Expedition 368 Moisture and Density

Moisture and density (MAD) data were acquired on ~10 mL sediment or rock samples by measuring three out of four material parameters: wet (saturated) mass, wet volume, dry mass, and/or dry volume after 24 h drying in a convection oven at 105 degrees C. From the moisture and volume measurements, the following phase relationships are calculated: wet and dry water content, wet bulk density, dry bulk density, grain density, porosity, and void ratio. The combination of measurements is defined by the submethod chosen: A, B, C, or D. Wet (A, B, or C) and dry (A, B, C, or D) mass is determined using motion-compensated balances. Wet volume is determined either by helium pycnometry (A) or by the sample's geometric dimensions using calipers (A or D). Dry volume (C or D) is measured by helium pycnometry. Submethods A and B are not recommended by IODP. Submethod C is suitable for saturated materials such as fine-grained sediments. Submethod D is suitable for unsaturated porous material such as certain limestones and basalts.含水率与密度（Moisture and Density, MAD）数据集针对约10毫升的沉积物或岩石样品采集得到，通过测定四项参数中的三项完成：湿（饱和）质量、湿体积、干质量，以及经105℃对流烘箱（convection oven）干燥24小时后的干体积。基于含水率与体积的测量结果，可计算得到如下相态参数：干湿含水率、湿体积密度、干体积密度、颗粒密度、孔隙率（porosity）以及孔隙比（void ratio）。测量组合由所选的子方法A、B、C或D确定。湿质量（对应子方法A、B或C）与干质量（对应子方法A、B、C或D）均通过运动补偿天平（motion-compensated balances）测定。湿体积可通过氦比重瓶法（helium pycnometry，子方法A）或使用游标卡尺（calipers）测量样品几何尺寸（子方法A或D）两种方式确定。干体积（子方法C或D）通过氦比重瓶法测定。国际大洋发现计划（International Ocean Discovery Program, IODP）不推荐使用子方法A与B。子方法C适用于饱和样品，例如细粒沉积物。子方法D适用于非饱和多孔介质，例如特定灰岩与玄武岩。