Flow rates, hydraulic conductivities and permeabilities of sediments from ODP Holes 190-1173A and 190-1174B@en

Understanding the role of fluids in active accretionary prisms requires quantitative knowledge of parameters such as permeability. We report here the results of permeability tests on four samples from Ocean Drilling Program Leg 190 at the Nankai Trough accretionary prism-two from Site 1173 and two from Site 1174. Volcanic ash is present in one of the samples; otherwise, the material is hemipelagic mud. A constant-rate-of-flow technique was used at various effective pressures and rates of flow. The permeability of the four samples ranges between 10**-15 and 10**-18 m**2, with the ash-bearing sample showing the highest values.要理解流体在活动增生楔（active accretionary prisms）中的作用，需掌握渗透率等参数的定量数据。本文报道了采自南海海沟（Nankai Trough）增生楔的大洋钻探计划（Ocean Drilling Program）第190航次的4个样品的渗透率测试结果：其中2个样品取自1173站位，另外2个取自1174站位。1个样品含有火山灰，其余样品均为半远洋泥（hemipelagic mud）。本研究采用恒流测试技术（constant-rate-of-flow technique），在不同有效压力与流速条件下开展测试。4个样品的渗透率介于10⁻¹⁵至10⁻¹⁸平方米之间，含火山灰的样品渗透率最高。