Characterisation of breccias in sediment core CRP-1 (Table 1)

CoreScan images were examined to determine the origin of breccias in the CRP-1 core. Breccias occur throughout the core. but are dominant deformation features in the upper 85 m. Breccia textures, boundaries and texture arrangements suggest that in situ fracturing and horizontal planar shearing are important deformation mechanisms in the upper part of the Miocene section. Forceful injections of silt and clay into fractures point to dewatering of overpressurised sediment. Breccias located below 55 metres below the sea floor (mbsf) occur associated with soft-sediment deformation, which is absent in younger intervals of the core. Deformation styles interpreted from the breccia textures, their downcore distribution, and the relations of breccias with sequence boundaries and lithologies, such as diamictites and graded beds, suggest brecciation occurred as a result of subglacial shearing and mass-movement processes. […]

对 CoreScan 图像进行了分析，以确定 CRP-1 核心中砾岩的起源。砾岩在全核中均有分布，但在上部 85 米处表现为主要的变形特征。砾岩的纹理、边界及其纹理排列表明，在渐新统上部，原地破裂和水平平面剪切是重要的变形机制。强烈的泥沙和粘土注入裂缝中，指向超压沉积物的脱水。位于海床以下 55 米（mbsf）以下的砾岩与软沉积变形相关联，而在核的较年轻层段中则不存在此类变形。从砾岩纹理、其向下的分布以及砾岩与层序界面和岩性（如泥石流和分级层）的关系所解读的变形样式表明，砾岩化是冰下剪切和大规模运动过程的结果。