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TitreUpper mantle structure underlying the diamondiferous Slave craton from teleseismic body-wave tomography
AuteurEsteve, C; Schaeffer, A J; Audet, P
SourceTectonophysics vol. 757, 2019 p. 187-202, https://doi.org/10.1016/j.tecto.2019.01.012
Année2019
Séries alt.Ressources naturelles Canada, Contribution externe 20190089
ÉditeurElsevier BV
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1016/j.tecto.2019.01.012
Mediapapier; en ligne; numérique
Formatspdf (Adobe® Reader®); html
SNRC64E; 64F; 64K; 64L; 64M; 64N; 65C; 65D; 65E; 65F; 65K; 65L; 65M; 65N; 66C; 66D; 66E; 66F; 66K; 66L; 66M; 66N; 67B; 67C; 67F; 67G; 74E; 74F; 74G; 74H; 74I; 74J; 74K; 74L; 74M; 74N; 74O; 74P; 75; 76; 77; 84E; 84F; 84G; 84H; 84I; 84J; 84K; 84L; 84M; 84N; 84O; 84P; 85; 86; 87; 94E; 94F; 94G; 94H; 94I; 94J; 94K; 94L; 94M; 94N; 94O; 94P; 95; 96; 97; 104H; 104I; 104P; 106A; 106H; 106I; 106P; 107A; 107D; 107E; 107H
Lat/Long OENS-129.0000 -100.0000 72.0000 57.0000
SujetsArchéen; études de la croûte; croûte continentale; craton; manteau terrestre; modèles sismiques; épaisseur de la croûte; interprétations géophysiques; interpretations sismiques; ondes sismiques; ondes P; ondes transversales; vitesse des ondes sismiques; anomalies; rangées sismiques; géologie du substratum rocheux; caractéristiques structurales; failles; zones de cisaillement; lithologie; roches ignées; roches intrusives; kimberlites; intrusions; métasomatose; terrains; cadre tectonique; séismologie; secousses séismiques; epicentres; Craton de Slave ; Bouclier Canadien; Champ de kimberlite de Lac de Gras; Cordillère canadienne; Terrane de Buffalo Head ; Arc de Great Bear ; Faille de Bathurst ; Zone de cisaillement de Great Slave Lake ; Orogène de Wopmay ; géologie structurale; géophysique; Phanérozoïque; Cénozoïque; Tertiaire; Mésozoïque; Crétacé; Précambrien
Illustrationsgeoscientific sketch maps; seismograms; cross-sections; profiles
Diffusé2019 03 02
Résumé(disponible en anglais seulement)
Cratons are, by definition, the most tectonically stable and oldest parts of the continental lithosphere on Earth. The Archean Slave craton is located in the northwestern part of the Canadian Shield. The propensity of diamondiferous kimberlite pipes in the Central Slave Craton raises many questions regarding their structural environment and source. Here, we provide the most robust teleseismic P and S body wave tomography models over the Slave craton region based on 20,547 P-wave delay times, 6140 direct S-wave delay times and 3381 SKS delay times. The P-wave model reveals an alternating pattern of relative positive and negative anomalies over a fine scale region within the Central Slave Craton. Furthermore, the P-wave model reveals two fine structures located in the lithosphere beneath the Lac de Gras kimberlite field, with relatively slow anomalies (B-C) that extend from 75 km to 350 km depths with an apparent dip to the north. These relatively slow P-wave anomalies are associated with metasomatised regions within the lithosphere. The most recent kimberlite pipes (75-45 Ma) in the Lac de Gras field are located on steep VP and VS gradients. The S-wave model displays a slow S-wave anomaly lying from 300 km depth to the transition zone beneath the Central Slave Craton. This anomaly is located beneath the Lac de Gras kimberlite field. We suggest that this anomaly is not the cause of the actual kimberlites at the surface since the last eruptions occurred 75-45 Ma ago but may be related to a potential kimberlite magma ascent in the asthenosphere.
GEOSCAN ID314743