IODP Expedition 368X Bulk and grain density (MAD)

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.水分与密度（Moisture and Density, MAD）数据集通过对约10 mL的沉积物或岩石样品测定四项材料参数中的三项采集得到，四项参数分别为湿（饱和）质量、湿体积、干质量，以及经105℃对流烘箱干燥24小时后的干体积。基于水分与体积的测定结果，可计算得到如下相态关系参数：湿态含水量、干态含水量、湿体积密度、干体积密度、颗粒密度、孔隙度及孔隙比。测定组合由所选子方法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）均采用运动补偿天平（motion-compensated balances）进行测定。湿体积可通过氦比重瓶法（helium pycnometry，对应子方法A）或使用游标卡尺（calipers）测量样品几何尺寸（对应子方法A或D）获取。干体积（对应子方法C或D）通过氦比重瓶法测定。国际大洋发现计划（IODP）不推荐使用子方法A与B。子方法C适用于细粒沉积物等饱和多孔材料。子方法D适用于某些石灰岩、玄武岩等非饱和多孔介质材料。