菲律宾海板块地壳结构特征:基于地震约束的重力反演  

Crustal Structure of Philippine Sea Plate: Insights from Gravity Inversions Constrained by Deep Seismic

作　　者：黄子强 吴招才 方银霞 许明炬 张家岭 Huang Ziqiang;Wu Zhaocai;Fang Yinxia;Xu Mingju;Zhang Jialing(Key Laboratory of Submarine Geoscience&Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China;College of Civil Engineering and Architecture,Zhejiang University of Water Resources and Electric Power,Hangzhou 310012,China;Ocean College,Zhejiang University,Zhoushan 316021,China)

机构地区：[1]自然资源部海底科学重点实验室,自然资源部第二海洋研究所,浙江杭州310012 [2]浙江水利水电学院建筑工程学院,浙江杭州310012 [3]浙江大学海洋学院,浙江舟山316021

出　　处：《地球科学》2025年第1期234-245,共12页Earth Science

基　　金：国家重点研发计划项目(No.2023YFC2808805);国家自然科学基金项目(No.42076078);中国-莫桑比克联合航次项目(No.GASI-01-DLJHJ-CM)。

摘　　要：为了深入理解菲律宾海板块各地质构造单元的深部结构以及九州-帕劳洋脊地壳特征,利用卫星测高重力异常,结合研究区域水深、沉积层厚度及洋壳年龄数据校正变密度沉积层重力效应和热扰动重力效应,并利用KPR上OBS剖面得到的莫霍面深度作为重力反演莫霍面的约束,计算了菲律宾海板块研究区的莫霍面深度及地壳厚度.结果显示菲律宾海板块整体地壳厚度呈现从西到东、从南到北依次增厚的特征.西菲律宾海盆莫霍面深度在10 km左右,地壳厚度在4 km左右.帕里西维拉海盆地壳厚度平均在7 km左右,大于年老的西菲律宾海盆.九州-帕劳洋脊地壳厚度最厚为14 km,在18°~19°N处厚度为8 km左右,接近帕里西维拉海盆洋壳厚度,不存在局部显著增厚地壳,KPR地壳为弧后岩浆活动改造的洋壳,而非成熟岛弧地壳.In order to understand the deep structure of the geological tectonic units of the Philippine Sea plate and the crustal feature of the Kyushu-Palau Ridge,this paper uses satellite gravity anomaly,combined with the bathymetry,sediment thickness and oceanic crust age data in the study area to correct the gravity effects of sediment and thermal disturbance.The Moho depth and crustal thickness of the Philippine Sea plate were calculated by combining Moho depth data from OBS profiles cross the KPR as constraints.The results show that the overall crustal thickness of the Philippine Sea plate is characterized by a gradual increase from west to east and from south to north.The Moho depth of the West Philippine Basin is about 10 km,with a crustal thickness of about 4 km.The average crustal thickness of the Parece Vela Basin is about 7 km,which is larger than that of the older West Philippine Basin.The crustal thickness of the Kyushu-Palau Ridge is 14 km at the maximum.In the 18°-19°N segment of the KPR,the crust is about 8 km,which is similar to the normal oceanic crust thickness in the Parece Vela Basin.There is no significant thickening crust.The crustal properties of the KPR are oceanic crust that has been thickened by back-arc magmatism,rather than mature island arc crust.

关 键 词：西菲律宾海盆 九州-帕劳洋脊 帕里西维拉海盆 地壳厚度 地壳性质 海洋地质学 

分 类 号：P67[天文地球—海洋地质]