Upper mantle anisotropy of southeast Arabia passive margin [Gulf of Aden northern conjugate margin], Oman
Upper mantle anisotropy of southeast Arabia passive margin [Gulf of Aden northern conjugate margin], Oman
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DOI：
10.1007/s12517-011-0477-2
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发表时间：
2012-09-01
影响因子：
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通讯作者：
Al-Toobi, Khalfan
中科院分区：
文献类型：
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作者：
Al-Lazki, Ali;Ebinger, Cindy;Al-Toobi, Khalfan
在这项研究中，我们使用的数据记录的亚丁湾北方边缘，佐法尔地区，阿曼苏丹国的两个连续的被动宽带部署。这些部署的目的是绘制年轻的亚丁湾东部被动大陆边缘地壳和上地幔结构和流变图。在这项研究中，我们使用剪切波分裂分析映射的横向变化的上地幔各向异性下研究区。在这项研究中，我们发现分裂幅度在0.33和1.0秒的延迟时间之间变化，平均约0.6秒，共17站从两个部署期间。结果表明，沿研究区横向各向异性沿着有明显的突变。三个各向异性带被确定：一个以NW-SE各向异性取向为主的西部带，一个以NE-SW各向异性取向为主的东部带，以及具有类似于东部和西部带的混合各向异性取向的中部带。我们解释这些较短波长的各向异性带可能代表化石岩石圈地幔各向异性。我们假设，中央各向异性带可能代表一个元古代缝合带，该缝合带将其东西两个地幔柱分开，东西各向异性带被用来指示具有不同上地幔各向异性特征的不同地幔柱。
In this study, we used data recorded by two consecutive passive broadband deployments on the Gulf of Aden northern margin, Dhofar region, Sultanate of Oman. The objective of these deployments is to map the young eastern Gulf of Aden passive continental margin crust and upper mantle structure and rheology. In this study, we use shear-wave splitting analysis to map lateral variations of upper mantle anisotropy beneath the study area. In this study, we found splitting magnitudes to vary between 0.33 and 1.0 s delay times, averaging about 0.6 s for a total of 17 stations from both deployment periods. Results show distinct abrupt lateral anisotropy variation along the study area. Three anisotropy zones are identified: a western zone dominated by NW-SE anisotropy orientations, an eastern zone dominated with NE-SW anisotropy orientations, and central zone with mixed anisotropy orientations similar to the east and west zones. We interpret these shorter wavelength anisotropy zones to possibly represent fossil lithospheric mantle anisotropy. We postulate that the central anisotropy zone may be representing a Proterozoic suture zone that separates two terranes to the east and west of it. The anisotropy zones west and east were being used indicative of different terranes with different upper mantle anisotropy signatures.