西南极特拉裂谷综合地球物理特征分析  

Geophysical characteristics of the Terror Rift,West Antarctica

作　　者：张峤 纪飞 ZHANG Qiao;JI Fei(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Research Center of Polar Geosciences,China Geological Survey,Beijing 100081,China;Key Laboratory of Paleomagnetism and Tectonic Reconstruction,Ministry of Natural Resources,Beijing 100081,China;National Institute of Natural Hazards,Ministry of Emergency Management of China,Beijing 100085,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]中国地质调查局极地地学研究中心,北京100081 [3]自然资源部古地磁与古构造重建重点实验室,北京100081 [4]应急管理部国家自然灾害防治研究院,北京100085

出　　处：《地质力学学报》2021年第5期809-820,共12页Journal of Geomechanics

基　　金：中国地质调查局中国地质科学院基本科研业务费项目(DZLXJK201903);国家自然科学基金(41706215);中国地质调查局地质调查项目(DD20190579);中央级公益性科研院所基本科研专项(ZDJ2019-30)。

摘　　要：特拉裂谷是西南极裂谷系统在新生代发生张裂作用的最后地区,因此成为研究西南极裂谷系统构造活动的关键。文章利用中国南极科考采集的以及SDLS国际共享的地震数据,结合多个钻探计划的钻井等基础资料,统一了西罗斯海地区地震反射界面和地震层序。将研究区的断层组合样式分为同沉积断层、层间断层和负花状断层三类,并进一步划分了区内新生代断层活动的期次,圈定了特拉裂谷的影响范围。研究发现,每期断层活动具有明显的继承性,活动时间由北部阿黛尔盆地向南部特拉裂谷越来越新,呈递变性,这是裂谷作用从北向南逐渐传递的结果。为了更加全面地揭示研究区的综合地球物理特征,利用基于弹性板模型下的Fan小波相关技术获得了研究区有效弹性厚度的空间变化特征。结果显示,横贯南极山脉前缘的异常低值条带与晚新生代的裂谷活动和伴生的岩浆作用有关,并指示了西罗斯海的拉张区域。In this paper,we investigated the Terror Rift where the last stage of Cenozoic rifting in the West Antarctic Rift System(WARS)took place.The International published and domestic sampled during CHARE seismic reflection profiles are utilized.Combining with drilling data,all the stratigraphic reflections are identified and unified in the entire study area for the subsequent interpretation.The rift fault patterns in the study area can be divided into syn-sedimentary faults,intra-layer faults and negative flower structure.According to faulting,we delineated the east and north boundary of the Terror Rift.Moreover,Cenozoic faulting activities are divided into three stages with strongly inheritance between each one of them.The timing of faulting activities gradually becomes younger from the Adare Basin in the north to the Terror Rift in the south,which is attributable to the transmission of rifting from north to south.In order to further reveal the geophysical characteristics of the study area,we investigated effective elastic thickness(EET)based on the fan wavelet transform technique.The anomalously low EET anomalies observed in the front of the Transantarctic Mountains(TAMs)is related to the rifting and magmatism in the late Cenozoic,probably indicating the extensional area of the western Ross Sea.

关 键 词：西南极 特拉裂谷 反射地震剖面 断层活动 有效弹性厚度 

分 类 号：P738[天文地球—海洋地质] P728[天文地球—海洋科学]