IODP Expedition 346 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.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参数中的三项来获取数据：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。基于水分与体积测量结果，可计算得到以下岩土相态参数：干湿含水率、湿容重、干容重、颗粒密度、孔隙度及孔隙比。 测量组合由选定的子方法（A、B、C或D）确定：采用运动补偿天平（motion-compensated balances）测定湿质量（对应子方法A、B或C）与干质量（对应子方法A、B、C或D）。湿体积可通过氦比重瓶法（helium pycnometry，子方法A）或采用游标卡尺测量样品几何尺寸（子方法A或D）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适用于细粒沉积物等饱和材料，子方法D适用于部分石灰岩、玄武岩等非饱和多孔材料。