New aeromagnetic view of the geological fabric of southern Dronning Maud Land and Coats Land, East Antarctica
New aeromagnetic view of the geological fabric of southern Dronning Maud Land and Coats Land, East Antarctica
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东南极洲德隆宁莫德地和科茨地南部地质构造的新航磁图
DOI：
10.1016/j.gr.2013.04.003
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发表时间：
2014
影响因子：
6.1
通讯作者：
W. Jokat
中科院分区：
文献类型：
--
作者：
M. Mieth;W. Jokat
南极洲的冰盾厚度达几公里，在试图解开冰下地质学时，这是一个挑战。在这里，我们报告了在过去十年中进行的系统的航空磁力调查，调查了德龙宁毛德地（DML）的重要部分，首次对东南极洲这一部分的内部地壳结构进行了成像。高分辨率的数据显示，在东南部的DML平行，细长的磁异常。这些西北-东南走向的异常可以追溯到更远的东方稀疏的俄罗斯磁测数据集。在DML西南部和科茨地观测到几个大于400 nT的高幅磁异常。它们在波长和振幅上与东部的磁场模式明显不同，并且没有显示任何证据表明有泛非造山带或缝合带将沙克尔顿山脉与东部DML连接起来，正如几项研究所假设的那样。这导致了一个迄今为止尚未认识到的大构造省在东南部DML的存在的假设。而在德龙宁毛德地内部超过100公里长的磁力线可能反映了一个类似于泛非时代Heimefrontfjella剪切带的主要剪切带。这两个发现为至今仍未解决的冈瓦纳大陆东西两部分的分离问题提供了新的证据。此外，磁测数据还可以绘制出科茨地（Coats Land）的东部范围，该地区被认为是重建罗迪尼亚的关键穿刺点。此外，南部非洲的贝蒂磁异常被认为将继续进入东南极洲。两个磁高在西部的DML被确定为可能向东延续这一突出的异常。
The ice shield of Antarctica, which measures several kilometers in thickness, presents a challenge when attempting to unravel the subglacial geology. Here, we report about systematic airborne magnetic surveys conducted over the last decade, which investigated a significant part of Dronning Maud Land (DML), imaging for the first time the crustal architecture of the interior of this sector of East Antarctica. High-resolution data reveal parallel, elongated magnetic anomalies in southeastern DML. These NW–SE trending anomalies can be traced farther east into sparser Russian magnetic data sets. Several high amplitude magnetic anomalies with values above 400 nT have been observed in southwestern DML and Coats Land. They differ clearly in wavelength and amplitudes from the magnetic pattern found in the east and do not show any evidence of a Pan-African orogenic belt or suture zone connecting the Shackleton Range with eastern DML, as hypothesized in several studies. This leads to the assumption of the existence of a hitherto unrecognized large tectonic province in southeastern DML. Whereas an over 100 km long magnetic lineament in the interior of the Dronning Maud Land may reflect a major shear zone akin to the Pan-African age Heimefrontfjella shear zone. Both findings bring new evidences to the still open question about the amalgation of East and West Gondwana. In addition, the magnetic data allow mapping the eastern extent of the presumable cratonic province of Coats Land, a region considered as a key piercing point for reconstructions of Rodinia. Furthermore, the Beattie Magnetic Anomaly in southern Africa is assumed to continue into East Antarctica. Two magnetic highs in western DML are identified as possible eastward continuation of this prominent anomaly.