Lithology description, textural and structural observations, and indications for ground ice of sediment core CRP-2 (Table 1-4)

From the upper 300 m of CRP-2/2A, twenty-six samples of diamicts and deformation structures have been thin sectioned. These have been analysed for texture, structure, diagenesis and plasmic fabric. The combination of certain microstructures (e.g. turbate and linear) and plasmic fabric development is indicative of grounded ice. Clear evidence for two grounded ice events (three samples) was found in the upper Oligocene part of the core. The interpretation of ten more samples is less certain, but as for CRP-1, is taken to point to grounded ice as well. There is a strong correlation between these indications for grounded ice and the basal part of cycles in the sequence stratigraphy.从CRP-2/2A钻孔的上部300米层段中，共采集26份冰碛物（diamicts）与变形构造样本并制备薄片，随后针对其结构、构造、成岩作用及基质组构（plasmic fabric）开展了系统分析。特定微观构造（如涡旋状构造与线状构造）与基质组构的组合发育特征，可作为陆基冰（grounded ice）存在的判别依据。在该岩心的渐新世（Oligocene）上部层位中，发现了2次陆基冰事件的明确证据，对应3份样本。其余10份样本的解释确定性相对较弱，但结合CRP-1钻孔的研究逻辑，同样被认定为指示陆基冰存在的迹象。上述陆基冰存在的指示标志，与层序地层学（sequence stratigraphy）中地层旋回的基底部位存在显著相关性。