Loss of strength caused by the destructuration of sensitive soils has been identified as the trigger of numerous landslides, some of them of devastating proportions. Norwegian sensitive clay deposits are typically found with a mineralogical composition of inert rock flour, including clay-sized chlorite and dioctahedral mica. The present paper presents a cross-scale study conducted on a sensitive clay from Norway with special focus on the role of mica on the material characteristics. Block samples of Onsøy clay obtained from different depths (4–10 m) were characterised and studied in terms of their mechanical properties, fabric and mineralogy. Oedometer compression tests were carried out in a high-pressure oedometer, applying stress up to 25 MPa on samples in an undisturbed and remoulded state. Microstructural investigations were carried out on undisturbed and remoulded samples using cryo-broadionbeam scanning electron microscopy (cryo-BIB-SEM). Mineral composition was analysed using X-ray diffraction on the bulk samples and the fraction ≤2 μm confirming absence of expandable clay minerals (smectites) and kaolinite. Coarse silt sized and irregular shaped particles were dominated by Na-rich and Ca-rich feldspar, quartz, and framboidal pyrite aggregates. A comparison with data sets from several Norwegian sensitive clay deposits showed that the plasticity index of these clays showed a tendency to decrease with an increasing amount of mica when the salinity is lower than 10 g/l. In contrast, for deposits with a salt concentration of more than 10 g/l, a significant increase in the plasticity index was observed with increasing amount of mica. The formation of aggregates was discussed with relation to its impact on the soil mechanical behaviour-

敏感土壤的破坏造成的强度损失已被确定为许多山体滑坡的触发因素，其中一些具有毁灭性的比例。挪威敏感的粘土矿床通常含有惰性岩粉的矿物成分，包括粘土大小的绿泥石和双八面体云母。本文介绍了对来自挪威的敏感粘土进行的跨尺度研究，特别关注云母对材料特性的作用。从不同深度 (4-10 m) 获得的 Onsøy 粘土块状样品在机械性能、结构和矿物学方面进行了表征和研究。固结仪压缩测试在高压固结仪中进行，在未受干扰和重塑状态下对样品施加高达 25 MPa 的应力。使用低温宽光束扫描电子显微镜 (cryo-BIB-SEM) 对未受干扰和重塑的样品进行微观结构研究。使用 X 射线衍射对大块样品和 ≤ 2 μm 的部分分析矿物成分，确认不存在可膨胀的粘土矿物（蒙脱石）和高岭石。粗粉砂大小和不规则形状的颗粒以富钠和富钙长石、石英和菱形黄铁矿聚集体为主。与来自几个挪威敏感粘土矿床的数据集的比较表明，当盐度低于 10 g/l 时，这些粘土的塑性指数显示出随着云母含量增加而降低的趋势。相反，对于盐浓度超过 10 g/l 的沉积物，随着云母量的增加，观察到可塑性指数显着增加。