Assembly and breakup of Gondwana - seismological signatures in the lithosphere/asthenosphere system of Southern Madagascar (SELASOMA)

冈瓦纳大陆的组装和分裂 - 马达加斯加南部岩石圈/软流圈系统中的地震特征（SELASOMA）

基本信息

批准号：
267795306
负责人：
Professor Dr. Georg Rümpker
金额：
--
依托单位：
Geological Survey of Norway (NGU)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/267795306?language=en
关键词：
Assembly breakup Gondwana seismological signatures

项目摘要

The assembly and destruction of supercontinents in the Wilson cycle is one of the defining paradigms for understanding the plate tectonic history beyond the time recorded by seafloor magnetic lineations. In this context the question arises to what extent the location and mode of breakup is controlled by ancient fabric formed during earlier cycles. Complementary to this issue is the question to what extent major episodes of suturing or rifting overprint earlier fabric, and how these earlier events influence recent kinematics. Whereas these questions have been addressed extensively by geological investigations, the dynamics of these processes are likely to be strongly influenced by the rheology of the mid- and lower crust and the mantle part of the lithosphere, best characterised by seismological investigations. The island of Madagascar occupied a key region in both the assembly and the multi-stage breakup of Gondwanaland (Stern 1994), itself part of the super-continent Pangaea. Madagascar consists of amalgamated continental material comprising several distinct tectonic units, with the oldest rocks being of Archaean age (3.2 Ga). Major geological boundaries generally follow a N-S trend mirroring the geographic orientation of the island. Its Proterozoic to early Paleozoic fabric is characterised by a shear-zone network spanning hundreds of kilometers, with some of the branches running oblique to the N-S trend, in particular in the south of the island. More recently during the Neogene, moderate volcanism has occurred in the Central and Northern part of the island, and there are indications of uplift throughout Eastern Madagascar over the last 10 Ma (Roberts et al. 2012). Although Madagascar is located within the interior of the African plate and far away from major plate boundaries, its seismic activity indicates that some deformation is taking place. Present-day kinematic models based on geodetic data and earthquake moment tensors identify a diffuse N-S-oriented minor boundary separating two microplates, which appears to pass through Madagascar (Stamps et al. 2008). Because of its key role in the assembly of Gondwana, numerous geological investigations have been carried out in Madagascar. However, comparatively little is known about the sub-surface structure as few focused seismological studies have been carried out in Madagascar. In this proposal we aim to characterise the lithospheric structure of southern Madagascar using data from a passive seismic experiment, which we carried out from May 2012 to May 2014. This experiment included an approximately E-W oriented profile of broadband stations across the island (operating for two years), and an areal array of short-period stations (operated for one year). The profile crosses all major geologic provinces and the short-period array will be used to map local seismicity and provide additional control on the 3-dimensional structure of the lithosphere/asthenosphere system.

威尔逊周期中超强的组装和破坏是理解板构造历史的定义范式之一，超过了海底磁性线索记录的时间。在这种情况下，问题出现在多大程度上由早期周期中形成的古代织物控制的位置和模式。对这个问题的补充是一个问题，在多大程度上缝合或裂开覆盖早期结构的主要事件，以及这些早期事件如何影响最近的运动学。尽管这些问题已通过地质研究广泛解决，但这些过程的动态可能会受到中层和下层外壳和岩石圈地幔部分的流变性的强烈影响，这是通过地震学研究的最佳特征。马达加斯加岛占据了贡德瓦纳兰德大会和多阶段分手的关键区域（Stern 1994），这本身就是超大型Pangea的一部分。马达加斯加由融合的大陆材料组成，其中包括几个不同的构造单元，最古老的岩石是古时代（3.2 GA）。主要地质边界通常遵循N-S趋势，反映了该岛的地理方向。它的原始古生代至早期的古生代织物的特征是跨越数百公里的剪力区网络，其中一些分支倾斜至N-S趋势，尤其是在岛上的南部。最近，在新金元期间，在该岛的中部和北部发生了中等火山，在过去的10个MA中，马达加斯加东部有升高的迹象（Roberts等，2012）。尽管马达加斯加位于非洲板块内部，远离主要板块边界，但其地震活动表明正在发生一些变形。基于测量数据和地震矩张量基于地震量的当今运动学模型确定了一个面向N-S面向N-S的次要边界，将两个微型板隔开，这似乎通过了马达加斯加（Stamps等，2008）。由于它在冈瓦纳集会中的关键作用，在马达加斯加进行了许多地质调查。然而，对于在马达加斯加进行的几乎没有集中的地震学研究，对地下结构的了解很少。在这项建议中，我们旨在使用被动地震实验的数据来表征马达加斯加南部的岩石圈结构，我们从2012年5月至2014年5月进行。该实验包括大约在岛上的宽带站（运营两年）的宽带宽带概况，以及一个近period站的阵列（一年）。该剖面横穿所有主要地质省，短期阵列将用于绘制局部地震性，并对岩石圈/运动层系统的3维结构提供额外的控制。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The structure of the crust and uppermost mantle beneath Madagascar

马达加斯加下方地壳和最上地幔的结构

DOI：
10.1093/gji/ggx243
发表时间：
2017
期刊：
Geophysical Journal International
影响因子：
2.8
作者：
Andriampenomanana;Nyblade;Wysession;Durrheim;Tilmann;Julià;Rambolamanana;Aleqabi;Rakotondraibe
通讯作者：
Rakotondraibe

Crustal structures in southern Madagascar and Sri Lanka in the context of Gondwana’s assembly and break-up: A study based on surface wave dispersion and receiver functions

冈瓦纳大陆组装和破碎背景下马达加斯加南部和斯里兰卡的地壳结构：基于表面波色散和接收函数的研究

DOI：
10.17169/refubium-27001
发表时间：
2020
期刊：
影响因子：
0
作者：
Jennifer Dreiling
通讯作者：
Jennifer Dreiling

Crustal Radial Anisotropy and Linkage to Geodynamic Processes: A Study Based on Seismic Ambient Noise in Southern Madagascar

DOI：
10.1029/2017jb015273
发表时间：
2018-06
期刊：
Journal of Geophysical Research: Solid Earth
影响因子：
0
作者：
J. Dreiling;F. Tilmann;X. Yuan;J. Giese;E. Rindraharisaona;G. Rümpker;M. Wysession
通讯作者：
J. Dreiling;F. Tilmann;X. Yuan;J. Giese;E. Rindraharisaona;G. Rümpker;M. Wysession

Seismic anisotropy of the lithosphere and asthenosphere beneath southern Madagascar from teleseismic shear wave splitting analysis and waveform modeling