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TitleAfrican cratonic lithosphere carved by mantle plumes
AuthorCelli, N L; Lebedev, S; Schaeffer, A JORCID logo; Gaina, C
SourceNature Communications vol. 11, 92, 2020 p. 1-10, https://doi.org/10.1038/s41467-019-13871-2 Open Access logo Open Access
Year2020
Alt SeriesNatural Resources Canada, Contribution Series 20190347
PublisherSpringer Nature
Documentserial
Lang.English
Mediapaper; on-line; digital
File formatpdf; html
AreaAfrica
Lat/Long WENS -25.0000 65.0000 40.0000 -40.0000
Subjectstectonics; geophysics; Nature and Environment; Science and Technology; crustal evolution; tectonic history; craton; lithosphere; continental crust; crustal thickness; mantle; volcanism; magmatism; emplacement; erosion; mobile belts; plate motions; geophysical interpretations; seismic data; kimberlites; mineral occurrences; diamond; Archean; models; Reguibat Shield; Man-Lèo Shield; Gabon-Cameroon Shield; Bomu-Kibali Shield; Uganda Shield; Tanzania Shield; Kasai Shield; Angola Shield; Bangweulu Block; Zimbabwe Shield; Limpopo Block; Kaapvaal Shield; Oubanguides Mobile Belt; Irumide Mobile Belt; Damara Mobile Belt; Namaqua Mobile Belt; Lufilian Arc; Rehoboth Province; Arabian Shield; West African Shear Zone; East African Orogenic Zone; Cameroon Line; mantle plumes; seismic tomography; large igneous provinces (LIP); Archean shields; hotspots; Precambrian; Proterozoic
Illustrationslocation maps; geoscientific sketch maps; 3-D models; histograms
ProgramPublic Safety Geoscience, Assessing Earthquake Geohazards
Released2020 01 03
AbstractHow cratons, the ancient cores of continents, evolved since their formation over 2.5 Ga ago is debated. Seismic tomography can map the thick lithosphere of cratons, but its resolution is low in sparsely sampled continents. Here we show, using waveform tomography with a large, newly available dataset, that cratonic lithosphere beneath Africa is more complex and fragmented than seen previously. Most known diamondiferous kimberlites, indicative of thick lithosphere at the time of eruption, are where the lithosphere is thin today, implying surprisingly widespread lithospheric erosion over the last 200 Ma. Large igneous provinces, attributed to deep-mantle plumes, were emplaced near all lithosphere-loss locations, concurrently with or preceding the loss. This suggests that the cratonic roots foundered once modified by mantle plumes. Our results imply that the total volume of cratonic lithosphere has decreased since its Archean formation, with the fate of each craton depending on its movements relative to plumes.
Summary(Plain Language Summary, not published)
In this paper, the relationship between the architecture of the lithospheric mantle and the location of diamondiferous kimberlites is explored, in the context of the African Continent. Like Canada, the African continent is constructed over several periods of super continent building, with old cratonic cores now deeply burried within the continental interior. Through new high resolution imaging, we observe that these once stable, highly rigid blocks, are actually more altered and carved than previously thought. This has implications on the longevity of the most stable parts of the continents, and has implications on similar cratonic cores within the stable Canadian Shield.
GEOSCAN ID321459

 
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