Abstract During the early Oligocene northeast Africa (Ethiopia, Sudan, Egypt) and Arabia (Yemen, Saudi Arabia, Jordan, Sinai and southern Israel) progressively emerged from marine conditions. Their complete subaerial exposure was accompanied by widespread erosion. Its products were transported across northeast Gondwana to the nearby Mediterranean and Mesopotamian basins while leaving behind a Regional Truncation Surface (RTS). The uplift mechanism is debated. Some claim it results from the Oligocene updoming of Afar mantle plume across northeastern Gondwana. Others suggest Gondwana Eurasia convergence that reached hard-docking during the Oligocene is the dominant process. Miocene-to-Holocene post-truncation tectonics deformed the leveled RTS (peneplain) relief while erosion continued. As a result, only scarce and widely distributed evidence for erosion remained across Arabia. The current study addresses this debate through the examination of the morphological development of the converging plate on the verge of entering the subduction zone. The study focuses on the mode of erosion across the Galilee basins of northern Israel. Based on the interpretation of 69 multichannel seismic reflection profiles (extending along 800 km), correlated with 68 boreholes and all previous geological mapping, we distinguish between pre-, syn- and post-truncation stratigraphic units. Results show that the RTS subcrop comprises a mosaic of diachronous formations, spanning the Upper Cretaceous and Oligocene. Stratigraphy constrains the overall duration of truncation between Late Eocene and Early Miocene. A new observation into the truncation period shown here enhances the morphological expression of ocean bottom exposure. The maximum thickness of strata removed reaches ˜1300 m during a 7 ± 2 million year time window. A conservative time estimation yields a weathering rate of 0.186 ± 0.058 mm per year, under a subtropical climate suggested for the Oligocene in this region. Preservation of syn-truncation sediments in local fault-bounded depressions attests to a regional NNE trending flexural uplift accompanied by local extensions. Truncation sediments derived from these erosional events accumulated across the western and eastern flanks of the Galilee, under marine conditions. We suggest that this flexure developed along a northward propagating arm of the Afar plume. This case study may serve as an example for the morphological development of a tectonic plate before its entrance into a subduction zone.

中文翻译：

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特提斯洋撤退和大陆渗透——以阿拉伯西北部加利利为例

摘要 在渐新世早期，非洲东北部（埃塞俄比亚、苏丹、埃及）和阿拉伯（也门、沙特阿拉伯、约旦、西奈半岛和以色列南部）逐渐脱离海洋条件。它们完全的地下暴露伴随着广泛的侵蚀。其产品穿过冈瓦纳大陆东北部运输到附近的地中海和美索不达米亚盆地，同时留下区域截断面 (RTS)。提升机制存在争议。一些人声称它是由渐新世横跨冈瓦纳大陆东北部的阿法尔地幔柱上升造成的。其他人认为，在渐新世期间达到硬对接的冈瓦纳欧亚大陆汇聚是主要过程。中新世至全新世的截断后构造使平坦的 RTS（半平原）地貌变形，而侵蚀仍在继续。因此，只有稀少且广泛分布的侵蚀证据在整个阿拉伯地区仍然存在。目前的研究通过检查即将进入俯冲带的会聚板块的形态发展来解决这一争论。该研究侧重于以色列北部加利利盆地的侵蚀模式。基于对 69 个多道地震反射剖面（沿 800 公里延伸）的解释，与 68 个钻孔和所有以前的地质图相关联，我们区分了截断前、同向和截断后地层单元。结果表明，RTS 亚季作物包括一个跨越上白垩统和渐新世的历时地层镶嵌。地层限制了晚始新世和早中新世之间截断的总持续时间。此处显示的截断期的新观察增强了海底暴露的形态表达。在 7 ± 2 百万年的时间窗口内，去除的地层的最大厚度达到 ~ 1300 m。在该地区渐新世建议的亚热带气候下，保守的时间估计产生每年 0.186 ± 0.058 毫米的风化率。局部断层界凹陷中同截断沉积物的保存证明了区域 NNE 趋势弯曲隆升伴随着局部伸展。在海洋条件下，由这些侵蚀事件产生的截断沉积物在加利利的西侧和东侧积累。我们认为这种弯曲是沿着阿法尔羽流向北传播的臂发展起来的。