西北印度洋卡尔斯伯格脊61°24′E-61°48′E段的构造地貌及岩浆-构造活动性  

The tectonic geomorphology and magmatic-tectonic activity in the 61°24′E-61°48′E segment of the Carlsberg Ridge in the Northwest Indian Ocean

作　　者：叶盛源 韩喜球 李洪林 YE Shengyuan;HAN Xiqiu;LI Honglin(Second Institute of Oceanography,MNR,Hangzhou 310012,China;Laboratory of Submarine Geosciences,MNR,Hangzhou 310012,China)

机构地区：[1]自然资源部第二海洋研究所,浙江杭州310012 [2]自然资源部海底科学重点实验室,浙江杭州310012

出　　处：《海洋学研究》2024年第4期70-82,共13页Journal of Marine Sciences

基　　金：浙江省基础公益研究计划青年基金项目(LQ19D060006);国家重点研发计划(2021YFF0501304)。

摘　　要：洋中脊的地形地貌特征直接受构造运动和岩浆活动控制,对其进行研究可以了解洋中脊的构造演化历史和岩浆作用过程,对于海底矿产资源的勘探具有重要意义。本文利用中国大洋24航次采集的船载多波束声呐数据,用定量分析的方法对西北印度洋卡尔斯伯格脊61°24′E-61°48′E段的地形地貌特征开展研究,计算了岩浆侵入比及断层相关指数,并探讨了研究区的岩浆-构造意义,获得了以下认识:1)研究区可划分为A、B、C、D四个二级洋中脊段,其岩浆-构造活动期间隔分别为0.15、0.50、0.70和0.21 Ma。2)洋中脊A段和B段为不对称扩张段,岩浆贫乏,以构造作用为主,处于构造活动期;洋中脊C段为对称扩张段,岩浆较为充足,以岩浆作用为主,处于轴向火山脊构建期;洋中脊D段为对称扩张段,岩浆贫乏,以构造作用为主,处于构造活动期。3)在洋中脊段两侧断层核密度值高的区域,有可能形成热液活动区,将是未来进一步勘探的目标区域。The topographic and geomorphologic features of mid-ocean ridges are directly controlled by tectonic movements and magmatic activities,and study of them can help us to understand the tectonic evolution history and magmatic processes of mid-ocean ridges,and is also of great significance to the exploration of deep-sea mineral resources.In this paper,the shipboard multibeam sonar data collected during the China Ocean 24 Cruise were utilize to study the topographic and geomorphologic features of the Carlsberg Ridge in the Northwest Indian Ocean by applying the quantitative analysis method with the 61°24′E-61°48′E segment as the research target,the magma intrusion ratio and the fault correlation index were calculated,and the magma-tectonic significance of the study area was discussed.The study area can be divided into four secondary mid-ocean ridge segments(A,B,C,and D).The active intervals of magma-tectonic periods for segments A,B,C,and D are 0.15,0.50,0.70 and 0.21 Ma,respectively.The mid-ocean ridge segments A and B are asymmetric dilatation sections with poor magma and mainly tectonic action,belonging to the period of tectonic activity;the mid-ocean ridge segment C is a symmetric dilatation section with sufficient magma and mainly magmatic action,belonging to the period of axial volcanic ridge construction;the mid-ocean ridge segment D is a symmetric dilatation section with poor magma and mainly tectonic action,belonging to the period of tectonic activity.Faults area with high kernel density on the two flanks of the mid-ocean ridge section has a possibility of forming an area of hydrothermal activity,which is a target area of further exploration.

关 键 词：卡尔斯伯格脊 地形地貌 岩浆周期 定量分析 岩浆-构造活动 岩浆侵入比 不对称扩张 核密度 

分 类 号：P736.1[天文地球—海洋地质]