Mantle Anisotropy in NW Namibia From XKS Splitting: Effects of Asthenospheric Flow, Lithospheric Structures, and Magmatic Underplating

被引：4
作者：
Komeazi, Abolfazl [1 ]
Kaviani, Ayoub [1 ]
Ruempker, Georg [1 ,2 ]
机构：
[1] Goethe Univ Frankfurt, Inst Geosci, Frankfurt, Germany
[2] Frankfurt Inst Adv Studies, Frankfurt, Germany
来源：
GEOPHYSICAL RESEARCH LETTERS | 2023年 / 50卷 / 03期
关键词：
seismic anisotropy; Tristan da Cunha mantle plume; Namibia; lithospheric shearing; continental breakup; shear wave splitting; SEISMIC ANISOTROPY; WALVIS RIDGE; KAOKO BELT; BENEATH; PLUME; DEFORMATION; HOTSPOT; EVOLUTION; VOLCANISM; JUNCTION;
D O I：
10.1029/2022GL102119
中图分类号：
P [天文学、地球科学];
学科分类号：
07 ;
摘要：
The presence of the Etendeka flood basalts in northwestern Namibia is taken as evidence for the activity of the Tristan da Cunha mantle plume during the continental breakup between Africa and South America. We investigate seismic anisotropy beneath NW Namibia by splitting analysis of core-refracted teleseismic shear waves (XKS phases) to probe mantle flow and lithospheric deformation related to the tectonic history of the region. We present the results of the joint splitting analysis of XKS data collected from 34 onshore stations and 12 ocean-bottom seismometers. The fast polarization directions (FPDs) are consistent with a model that combines the effects of lithospheric deformation and large-scale mantle flow due to the NE motion of the African plate. The dominantly NNW-SSE-oriented FPDs in the northern part are likely caused by shallow lithospheric structures. Our observations do not show any strong evidence of a pervasive effect of the Tristan da Cunha mantle plume.
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页数：11
相关论文
共 61 条
[1]   Lithospheric anisotropy beneath the Pyrenees from shear wave splitting [J].
Barruol, G ;
Souriau, A ;
Vauchez, A ;
Diaz, J ;
Gallart, J ;
Tubia, J ;
Cuevas, J .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 1998, 103 (B12) :30039-30053
[2]   Upper mantle anisotropy beneath the African IRIS and Geoscope stations [J].
Barruol, G ;
Ben Ismail, W .
GEOPHYSICAL JOURNAL INTERNATIONAL, 2001, 146 (02) :549-561
[3]  
Barruol G., 2009, SKS SPLITTING DATABA
[4]   Mantle flow beneath La Reunion hotspot track from SKS splitting [J].
Barruol, Guilhem ;
Fontaine, Fabrice R. .
EARTH AND PLANETARY SCIENCE LETTERS, 2013, 362 :108-121
[5]   The lithospheric architecture of Africa: Seismic tomography, mantle petrology, and tectonic evolution [J].
Begg, G. C. ;
Griffin, W. L. ;
Natapov, L. M. ;
O'Reilly, Suzanne Y. ;
Grand, S. P. ;
O'Neill, C. J. ;
Hronsky, J. M. A. ;
Djomani, Y. Poudjom ;
Swain, C. J. ;
Deen, T. ;
Bowden, P. .
GEOSPHERE, 2009, 5 (01) :23-50
[6]   Abrupt plate accelerations shape rifted continental margins [J].
Brune, Sascha ;
Williams, Simon E. ;
Butterworth, Nathaniel P. ;
Mueller, R. Dietmar .
NATURE, 2016, 536 (7615) :201-+
[7]   Quantifying the thermo-mechanical impact of plume arrival on continental break-up [J].
Brune, Sascha ;
Popov, Anton A. ;
Sobolev, Stephan V. .
TECTONOPHYSICS, 2013, 604 :51-59
[8]   The upper mantle beneath the South Atlantic Ocean, South America and Africa from waveform tomography with massive data sets [J].
Celli, N. L. ;
Lebedev, S. ;
Schaeffer, A. J. ;
Ravenna, M. ;
Gaina, C. .
GEOPHYSICAL JOURNAL INTERNATIONAL, 2020, 221 (01) :178-204
[9]   SHEAR-WAVE SPLITTING IN THE LOWER CRUST BENEATH THE ARCHEAN CRUST OF SOUTHWEST GREENLAND [J].
CLEMENT, WP ;
CARBONELL, R ;
SMITHSON, SB .
TECTONOPHYSICS, 1994, 232 (1-4) :195-210
[10]   Shear wave splitting at the Hawaiian hot spot from the PLUME land and ocean bottom seismometer deployments [J].
Collins, John A. ;
Wolfe, Cecily J. ;
Laske, Gabi .
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, 2012, 13
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