Crustal structure of southern Madagascar from receiver functions and ambient noise correlation: Implications for crustal evolution
Crustal structure of southern Madagascar from receiver functions and ambient noise correlation: Implications for crustal evolution
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从接收函数和环境噪声相关性看马达加斯加南部的地壳结构：对地壳演化的影响
DOI：
10.1002/2016jb013565
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Barruol
中科院分区：
文献类型：
--
作者：
Rindraharisaona;Tilmann;Rümpker;Rambolamanana;Barruol
马达加斯加的前寒武纪岩石是在称为泛非造山运动的大陆碰撞期间形成和/或改变的。二叠纪-三叠纪卡鲁裂谷的中止以及随后与非洲和印度的分离导致了西部沉积盆地的形成，火山活动主要发生在边缘。许多地质研究已经记录了这些过程的印记，但对更深层次的结构知之甚少。因此，我们沿着东南-西北走向的剖面部署了地震台，几乎涵盖了马达加斯加南部的所有地质区域。在这里，我们重点关注地壳结构，该结构是根据接收器函数和环境噪声测量得出的表面波的联合分析确定的。对于沉积盆地，我们记录了下面的结晶基底变薄了约 60% 至 13 公里。地壳速度结构表明，减薄是通过下地壳的去除或折返而完成的。元古界和太古代地壳都有 10 公里厚的上地壳和 10-12 公里厚的中地壳。但与元古代和太古代地壳的典型结构相比，太古代下地壳比元古代地壳更厚、速度更快，表明可能存在岩浆侵入；厚度为 2-8 公里的底镀层仅存在于太古代地壳下方。元古代镁铁质下地壳可能在大陆碰撞过程中因分层或俯冲而消失，或由于伸展塌陷而变薄。最后，东海岸白垩纪火山岩的特点是地壳薄（30公里）和非常大的VP/VS比。
The Precambrian rocks of Madagascar were formed and/or modified during continental collision known as the Pan‐African orogeny. Aborted Permo‐Triassic Karoo rifting and the subsequent separation from Africa and India resulted in the formation of sedimentary basins in the west and volcanic activity predominantly along the margins. Many geological studies have documented the imprint of these processes, but little was known about the deeper structure. We therefore deployed seismic stations along an SE‐NW trending profile spanning nearly all geological domains of southern Madagascar. Here we focus on the crustal structure, which we determined based on joint analysis of receiver functions and surface waves derived from ambient noise measurements. For the sedimentary basin we document a thinning of the underlying crystalline basement by up to ∼60% to 13 km. The crustal velocity structure demonstrates that the thinning was accomplished by removal or exhumation of the lower crust. Both the Proterozoic and Archean crust have a 10 km thick upper crust and 10–12 km thick midcrust. However, in contrast to the typical structure of Proterozoic and Archean aged crust, the Archean lower crust is thicker and faster than the Proterozoic one, indicating possible magmatic intrusions; an underplated layer of 2–8 km thickness is present only below the Archean crust. The Proterozoic mafic lower crust might have been lost during continental collision by delamination or subduction or thinned as a result of extensional collapse. Finally, the Cretaceous volcanics along the east coast are characterized by thin crust (30 km) and very largeVP/VSratios.
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影响因子：
2.9
作者：
M. Pasyanos;A. Nyblade
通讯作者：
M. Pasyanos;A. Nyblade
马达加斯加中部地区震源参数和构造速度同步反演作为塔那那利佛减灾的前提
DOI：
--
发表时间：
1997
期刊：
影响因子：
--
作者：
G. Rambolamanana;P. Suhadolc;G. Panza
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DOI：
--
发表时间：
1982
期刊：
影响因子：
--
作者：
J. Boast;A. Nairn
通讯作者：
A. Nairn
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DOI：
--
发表时间：
2022
期刊：
影响因子：
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作者：
Sakane Fumio;Hoshino Fumi;Murakami Chiaki;植松 祐真
通讯作者：
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机载磁数据与马达加斯加南部地壳尺度剪切带岩石学的比较：破译造山地壳中岩浆和流体传输的工具
影响因子：
2.3
作者：
J. Martelat;B. Randrianasolo;K. Schulmann;J. Lardeaux;J. Devidal
通讯作者：
J. Devidal