南大西洋洋中脊板块构造运动过程:古地磁的约束

发布时间：2017-12-28 11:14

本文关键词：南大西洋洋中脊板块构造运动过程:古地磁的约束　出处：《地球物理学报》2016年05期 　论文类型：期刊论文

【摘要】：海底磁异常的形态与洋中脊两侧板块的微运动或变形密切相关.因此,这方面的研究可为确定板块运动的演化历史、小尺度的动力学过程以及洋中脊分段的机制等提供重要约束.本文对南大西洋一段洋中脊(31°S—34.5°S)两侧的磁异常的偏度进行了系统研究.结果表明研究区域内扩张方向并不总是垂直于洋中脊走向,并且研究区域不同剖面的扩张方向也不一致,具体表现为从北向南,平均扩张方向逐渐增加,依次为33.6°±5.3°、62.8°±13.0°以及94.3°±8.0°.这表明洋中脊的倾斜扩张机制具有复杂性,初步解释应该与转换断层的剪切应力增加有关.深部辉长岩层倾斜和扩张速率不对称性对海底磁异常偏度的影响值得深入研究.另外,由北向南确定的欧拉极向东移动,表明洋中脊两侧的板块在6.5 Ma期间存在剧烈形变.
[Abstract]:The morphology and magnetic anomaly in the ocean ridge on both sides of the micro plate movement or deformation are closely related. Therefore, this research can provide important constraints for the ridge segment determine the evolution history, the small scale movement of the plate dynamics and ocean mechanism. The south the Atlantic section of the mid ocean ridge (31 degrees S - 34.5 degrees S) on both sides of the skewness of the magnetic anomalies were studied. The results show that the study area is not always in the direction of expansion of vertical Yu Yang ridge direction and research direction of the regional expansion of different sections are inconsistent, the specific performance from north to south, the average expansion direction gradually increased, followed by 33.6 degrees - 5.3 degrees 62.8 degrees, plus or minus 13 degrees and 94.3 degrees - 8 degrees tilt. This shows that the expansion mechanism of the mid ocean ridge is complex, a preliminary explanation should transform faults and shear stress increases. The deep layer gabbro tilt and expansion rate asymmetry The influence of the magnetic anomaly bias on the seafloor is worth further study. In addition, the Euler polar eastward movement determined from north to South indicates that the plates on both sides of the mid ocean ridge exist severe deformation during the period of 6.5 Ma.
【作者单位】：中国科学院计算地球动力学重点实验室;中国科学院大学地球科学学院;中国科学院地质与地球物理研究所;青岛国家海洋科学技术实验室海洋地质过程与环境功能实验室;
【基金】：国家自然科学基金项目(41474086,41174084) 中国科学院与国家外国专家局创新团队国际合作伙伴计划项目(KZZD-EW-TZ-19) 海岸带地质调查工程-大陆架科学钻探项目(GZH201100202) 国家海洋局“全球变化与海气相互作用”专项(GASI-GEOGE-03)资助
【分类号】：P736.1;P318.44
【正文快照】： Paleomagnetic constraints on plate tectonic process at south mid-Atlantic ridgeLI Yuan-Jie1,2,WEI Dong-Ping1,2,LIU Qing-Song3,4*1引言在地质历史时期,地球磁场经历了多次极性倒转,洋中脊两侧喷发的岩浆冷却时,可以记录到当时地球磁场的信息.随后岩浆冷却形成洋壳,并

【相似文献】