凌子龙, 赵俐红, 彭祎辉, 吴招才, 曲彦丞. 基于滑动窗口导纳技术反演西太平洋中部岩石圈的有效弹性厚度[J]. 海洋地质与第四纪地质, 2021, 41(1): 138-146. DOI: 10.16562/j.cnki.0256-1492.2020112002
引用本文: 凌子龙, 赵俐红, 彭祎辉, 吴招才, 曲彦丞. 基于滑动窗口导纳技术反演西太平洋中部岩石圈的有效弹性厚度[J]. 海洋地质与第四纪地质, 2021, 41(1): 138-146. DOI: 10.16562/j.cnki.0256-1492.2020112002
LING Zilong, ZHAO Lihong, PENG Yihui, WU Zhaocai, QU Yancheng. Inversion of the lithosphere effective elastic thickness in the central Western Pacific with moving window admittance technique[J]. Marine Geology & Quaternary Geology, 2021, 41(1): 138-146. DOI: 10.16562/j.cnki.0256-1492.2020112002
Citation: LING Zilong, ZHAO Lihong, PENG Yihui, WU Zhaocai, QU Yancheng. Inversion of the lithosphere effective elastic thickness in the central Western Pacific with moving window admittance technique[J]. Marine Geology & Quaternary Geology, 2021, 41(1): 138-146. DOI: 10.16562/j.cnki.0256-1492.2020112002

基于滑动窗口导纳技术反演西太平洋中部岩石圈的有效弹性厚度

Inversion of the lithosphere effective elastic thickness in the central Western Pacific with moving window admittance technique

  • 摘要: 西太平洋中部地区是西太平洋板块边缘沟-弧-盆体系构造演化的关键区域,其地质特征与构造演化一直是地学家关注的焦点问题之一。开展岩石圈有效弹性厚度的研究对于认识该区域的形成演化具有重要的科学意义。本文采用滑动窗口导纳技术,并在挠曲模型中考虑了表面荷载和内部荷载同时存在的情况,计算得到该区域的岩石圈有效弹性厚度(Te)。计算结果显示,研究区的Te值整体上为0~50 km,其变化基本上与构造单元相吻合,且与主要的构造边界密切相关。除海底火山具有相对较小的Te值(15~20 km)外,太平洋板块整体上具有较强的岩石圈强度(25~30 km)。马里亚纳海沟和菲律宾海沟的岩石圈强度从外隆起到海沟方向表现为明显的减弱,表明岩石圈由外隆起向海沟发生了弱化。帕里西维拉海盆西部相较于东部具有较弱的岩石圈强度,这可能与海盆的非对称扩张有关。卡罗琳板块的岩石圈整体上表现为相对均一的低Te值特征(<15 km)。欧里皮克海隆、卡罗琳海岭和索罗尔海槽的Te值为3 km,这可能是强烈的火山作用所导致的结果。

     

    Abstract: The Central Western Pacific is a key area for study of the tectonic evolution of a trench-arc-basin system. The geological features and tectonic evolution of the region have raised great attention from geologists. In this paper, the lithospheric effective elastic thickness (Te) is used as a parameter for understanding the tectonic-magmatic processes of the region and the Moving Window Admittance Technique is adopted as the major tool to calculate the Te for the study region, which considers both the surface and internal loads in a flexure model. The calculated results show that the Te values in the Central Western Pacific vary from 0~50 km, and the variation is closely related to major tectonic boundaries, and agrees well with tectonic provinces of the study area. In general, the Pacific Plate is characterized by high Te up to 25~30 km. Te values are relatively low in the submarine volcanic area (15~20 km). The noticeable reduction of Te is observed on the subducting plate from the outer rise to the trench axis of the Mariana Trench and the Philippine Trench, suggesting that the lithosphere is weakened from the outer rise to trench. The lithospheric strength in the western part of the Parece Vela Basin is weaker than that in the eastern part, possibly related to the asymmetric spreading of the basin. The lithosphere of the Caroline Plate is characterized by relatively uniform low Te values. The lithosphere in the Eauripik Rise, Caroline Ridge and Sorol Trough vary around a Te of 3 km, resulted from strong volcanism.

     

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