DOI: 10.1007/s00531-015-1279-7
Scopus记录号: 2-s2.0-84949635083
论文题名: Aeromagnetic interpretation in the south-central Zimbabwe Craton: (reappraisal of) crustal structure and tectonic implications
作者: Ranganai R.T. ; Whaler K.A. ; Ebinger C.J.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2016
卷: 105, 期: 8 起始页码: 2175
结束页码: 2201
语种: 英语
英文关键词: Aeromagnetic anomalies
; Crustal domains
; Limpopo Belt
; Structural trends
; Tectonic evolution
; Zimbabwe Craton
Scopus关键词: aeromagnetic survey
; crustal structure
; deformation
; greenstone belt
; magnetic anomaly
; mapping
; tectonic evolution
; Limpopo Belt
; Zimbabwe Craton
英文摘要:
Regional aeromagnetic data from the south-central Zimbabwe Craton have been digitally processed and enhanced for geological and structural mapping and tectonic interpretation integrated with gravity data, to constrain previous interpretations based on tentative geologic maps and provide new information to link these structural features to known tectonic events. The derived maps show excellent correlation between magnetic anomalies and the known geology, and extend lithological and structural mapping to the shallow/near subsurface. In particular, they reveal the presence of discrete crustal domains and several previously unrecognised dykes, faults, and ultramafic intrusions, as well as extensions to others. Five regional structural directions (ENE, NNE, NNW, NW, and WNW) are identified and associated with trends of geological units and cross-cutting structures. The magnetic lineament patterns cut across the >2.7 Ga greenstone belts, which are shown by gravity data to be restricted to the uppermost 10 km of the crust. Therefore, the greenstone belts were an integral part of the lithosphere before much of the upper crustal (brittle) deformation occurred. Significantly, the observed magnetic trends have representatives craton-wide, implying that our interpretation and inferences can be applied to the rest of the craton with confidence. Geological–tectonic correlation suggests that the interpreted regional trends are mainly 2.5 Ga (Great Dyke age) and younger, and relate to tectonic events including the reactivation of the Limpopo Belt at 2.0 Ga and the major regional igneous/dyking events at 1.8–2.0 Ga (Mashonaland), 1.1 Ga (Umkondo), and 180 Ma (Karoo). Thus, their origin is here inferred to be inter- and intra-cratonic collisions and block movements involving the Zimbabwe and Kaapvaal Cratons and the Limpopo Belt, and later lithospheric heating and extension associated with the break-up of Gondwana. The movements produced structures, or reactivated older fractures, that were exploited by Late Archaean and Proterozoic mafic intrusions. There was interplay between vertical and horizontal tectonics as seen in similar terrains worldwide. © 2015, Springer-Verlag Berlin Heidelberg.
URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84949635083&doi=10.1007%2fs00531-015-1279-7&partnerID=40&md5=8a32959a1eef9dddec50c652cd2348b5
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70101
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Physics Department, University of Botswana, P. Bag UB0704, Gaborone, Botswana; School of GeoSciences, University of Edinburgh, Grant Institute, James Hutton Road, Edinburgh, United Kingdom; Department of Earth and Environmental Sciences, 227 Hutchison Hall, University of Rochester, Rochester, NY, United States
Recommended Citation:
Ranganai R.T.,Whaler K.A.,Ebinger C.J.. Aeromagnetic interpretation in the south-central Zimbabwe Craton: (reappraisal of) crustal structure and tectonic implications[J]. International Journal of Earth Sciences,2016-01-01,105(8)