| Title | African cratonic lithosphere carved by mantle plumes |
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| Author | Celli, N L; Lebedev, S; Schaeffer, A J ; Gaina, C |
| Source | Nature Communications vol. 11, 92, 2020 p. 1-10, https://doi.org/10.1038/s41467-019-13871-2  Open Access |
| Year | 2020 |
| Alt Series | Natural Resources Canada, Contribution Series 20190347 |
| Publisher | Springer Nature |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html |
| Area | Africa |
| Lat/Long WENS | -25.0000 65.0000 40.0000 -40.0000 |
| Subjects | tectonics; 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; Precambrian; Proterozoic |
| Illustrations | location maps; geoscientific sketch maps; 3-D models; histograms |
| Program | Public Safety Geoscience Assessing Earthquake Geohazards |
| Released | 2020 01 03 |
| Abstract | How 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 ID | 321459 |
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