Physical/chemical properties and stable oxygen and carbon isotope records of Holocene to late Pleistocene sediments in the Gela Basin, central Mediterranean Sea

The Holocene Twin Slides form the most recent of recurrent mass wasting events along the NE portion of Gela Basin within the Sicily Channel, central Mediterranean Sea. Here, we present new evidence on the morphological evolution and stratigraphic context of this coeval slide complex based on deepdrilled sediment sequences providing a >100 ka paleo-oceanographic record. Both Northern (NTS) and Southern Twin Slide (STS) involve two failure stages, a debris avalanche and a translational slide, but are strongly affected by distinct preconditioning factors linked to the older and buried Father Slide. Core-acoustic correlations suggest that sliding occurred along sub-horizontal weak layers reflecting abrupt physical changes in lithology or mechanical properties. Our results show further that headwall failure predominantly took place along sub-vertical normal faults, partly through reactivation of buried Father Slide headscarps.全新世双滑坡（Holocene Twin Slides）是地中海中部西西里海峡内杰拉盆地（Gela Basin）东北部区域最为新近的周期性复发块体运动事件。本文基于可提供超过10万年古海洋学记录的深钻沉积序列，针对该同期滑坡复合体的地貌演化与地层背景提出新的研究证据。北部双滑坡（NTS）与南部双滑坡（STS）均包含两个破坏阶段：碎屑崩落与平移滑坡，但二者均受与埋藏式古老父滑坡（Father Slide）相关的独特预触发因素强烈影响。岩芯-声学关联分析表明，滑坡沿反映岩性或力学性质突变的近水平软弱层发生。研究结果进一步显示，滑坡后壁破坏主要沿近直立正断层发生，部分通过复活埋藏的父滑坡滑坡壁实现。