IODP Expedition 369 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（MAD）数据集通过对约10 mL的沉积物或岩石样品开展测试获取，测试时需测定四项材料参数中的三项：湿（饱和）质量、湿体积、干质量，以及/或经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，可计算得到如下三相参数关系：干湿含水率、湿表观密度、干表观密度、颗粒密度、孔隙率及孔隙比。测试组合由所选子方法（A、B、C或D）确定：采用运动补偿天平测定对应子方法A、B或C的湿质量，以及对应子方法A、B、C或D的干质量。湿体积可通过两种方式测定：氦比重瓶法（对应子方法A），或使用游标卡尺测量样品几何尺寸（对应子方法A或D）。干体积（对应子方法C或D）则通过氦比重瓶法测定。子方法A与B不被国际大洋发现计划（IODP）推荐。子方法C适用于细粒沉积物等饱和多孔材料，子方法D适用于特定石灰岩、玄武岩等非饱和多孔材料。