南极半岛西侧不活动陆缘陆架区新生代构造变形特征及沉积演化

发布时间：2018-04-29 11:43

本文选题：南极半岛西缘 + 构造层序　；参考：《地学前缘》2017年05期

【摘要】：基于横穿南极半岛西侧不活动陆缘陆架区的多道地震剖面解释,对该地区的新生代构造变形及沉积演化进行了研究。研究表明,南极半岛西侧陆缘陆架区可以划分为四大平行于南极半岛走向的构造单元,从陆侧至海侧,分别是陆架内缘区、陆架盆地、陆架中部隆起和陆架外缘区。同时通过地震剖面不整合面识别以及结合区域演化历史,对陆架外缘区层位进行了划分,共划分出四大构造层序:俯冲碰撞前层序S4,俯冲碰撞后层序S3,上新世冰川沉积S2及全新世冰海沉积S1。基于构造单元及构造层序的划分,将南极半岛西侧不活动陆缘陆架区的构造-沉积演化分为三期:(1)中生代—始新世,菲尼克斯板块向着南极半岛俯冲,南极半岛西侧陆缘为主动大陆边缘,陆架内缘区发生火山活动,形成海底火山岩,而在陆架盆地区和陆架外缘区沉积火山碎屑岩;(2)从始新世开始,南极洲-菲尼克斯洋中脊逐步分段式地抵达南极半岛西侧大陆边缘,南极半岛西缘逐渐转变成不活动的大陆边缘,并在陆架中部发生隆起作用,使得陆架盆地内的沉积物发生变形形成向斜构造,同时在陆架外缘区沉积硅质碎屑岩;(3)上新世开始,南极半岛西缘发生大规模的冰川作用,大陆边缘的沉积主要受控于冰川作用。
[Abstract]:Based on the multi seismic section interpretation of the inactive continental shelf area across the west side of Antarctic Peninsula, the tectonic deformation and sedimentary evolution of the Cenozoic in this area have been studied. The study shows that the continental shelf area of the western side of Antarctic Peninsula can be divided into four major tectonic units parallel to the strike of Antarctic Peninsula, from the land to the sea side, respectively, the inner edge of the continental shelf. In the area, the continental shelf basin, the central uplift of the continental shelf and the outer edge of the continental shelf. At the same time, through the identification of the unconformity surface of the seismic section and the history of the regional evolution, four tectonic sequences are divided and divided into two major tectonic sequences: the sequence S4 before subduction and collision, the sequence S3 after subduction and collision, the Pliocene glacial deposition of S2 and the Holocene glacial sea deposit S1. base In the division of tectonic units and tectonic sequences, the tectonic sedimentary evolution of the inactive continental shelf area on the west side of Antarctic Peninsula is divided into three stages: (1) Mesozoic Eocene, the Feinikesi plate subducted to Antarctic Peninsula, the continental margin of the west side of Antarctic Peninsula is active continental margin, volcanic activity in the inner margin of the continental shelf, and the formation of the submarine volcanic rocks. Sedimentary volcanic clastic rocks in the basin area and the outer margin of the continental shelf; (2) from the Eocene, the Antarctica Feinikesi mid ridge gradually reached the western edge of the western side of Antarctic Peninsula, and the western margin of Antarctic Peninsula gradually changed into an inactive continental margin and uplifted in the middle of the Continental shelf, making the sediments in the shelf basin changed. The formation of syncline is formed, and siliceous clastic rocks are deposited in the outer margin of the continental shelf. (3) a large scale glaciation occurred on the western margin of Antarctic Peninsula in the early Pliocene, and the continental margin deposits were mainly controlled by glacial action.

【作者单位】：国家海洋局海底科学重点实验室;国家海洋局第二海洋研究所;
【基金】：国家海洋局2014年度南极周边海域矿产资源潜力调查与评估极地专项(CHINARE2014-01-07) 国家海洋局海洋公益性行业科研专项(201205003);国家海洋局全球变化与海气相互作用专项(GASI-GEOGE-01) 浙江省自然科学基金项目(LQ12D06003)
【分类号】：P512.2;P542

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