Quaternary uplift along a passive continental margin (Oman, Indian Ocean)
Quaternary uplift along a passive continental margin (Oman, Indian Ocean)
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DOI：
10.1016/j.geomorph.2019.106870
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发表时间：
2020-02-01
期刊：
影响因子：
3.9
通讯作者：
Preusser, Frank
中科院分区：
文献类型：
--
作者：
Hoffmann, Goesta;Schneider, Bastian;Preusser, Frank
沿着阿曼阿拉伯海海岸线的地壳运动沿着72公里长的海岸段进行量化，其特征是海洋梯田的阶梯。对这些阶地进行了广泛的地形、地貌和地质调查，提出了基于宇宙成因核素（Be-10, Cl-36）和光激发发光测年的年龄模型，以及从高分辨率数字高程模型中提取古海岸线的新方法。隆升的地壳块体以断层为界，由上覆浅海相灰岩的逆冲相关橄榄岩组成。确定了9个不同的阶地水平，结果表明在海洋同位素阶段（MIS） 5a和MIS 19之间持续抬升。计算出的隆升速率沿海岸线变化，隆升的海岸块体向北倾斜被解释为差异隆升的证据。阶地的地貌证明倾斜一定发生在最后一次间冰期之后。讨论了与马克兰俯冲带有关的地壳前隆起对隆升的构造强迫作用。还得出结论认为，隆升包括橄榄岩的蛇纹石化过程和上覆石灰岩地层的岩溶作用。由于水在这两个过程中都是必不可少的，第四纪气候变化在隆升过程和水均衡过程中明显起着重要作用。(C) 2019 Elsevier B.V.版权所有
Crustal movement along the coastline of the Arabian Sea in Oman is quantified along a 72 km long coastal section characterised by staircases of marine terraces. An extensive topographic, geomorphological and geological survey was conducted on these terraces and an age model based on cosmogenic nuclide (Be-10, Cl-36) and optically stimulated luminescence dating is presented, together with a new approach to extract palaeo-shorelines from a high-resolution digital elevation model. The uplifting crustal block is fault bounded and is composed of obduction related peridotites overlain by shallow marine limestone. Nine distinct terrace levels are identified and the results indicate continuous uplift between Marine Isotope Stage (MIS) 5a and MIS 19. The calculated uplift rates vary along the coastline and a northward tilting of the uplifted coastal block is interpreted as evidence for differential uplift. The geomorphology of the terraces proves that the tilting must have taken place after the last interglacial. Tectonic forcing of the uplift by a crustal forebulge associated with the Makran Subduction Zone is discussed. It is also concluded that the uplift involves processes of serpentinisation of the peridotites in combination with karstification of the overlying limestone formations. As water is essential for both processes, climate change during the Quaternary apparently played a significant role in the uplift process as well as hydro-isostasy. (C) 2019 Elsevier B.V. All rights reserved.