Petrology and Structural Characterization of Post-Neoproterozoic Dolerites from the Kimberlite Fields in the Kéniéba Region (Western Mali)  

作　　者：Gbele Ouattara Baco Traore Ziandjêdé Hervé Siagné Aboubacar Denon Souleymane Sangare Marc Ephrem Allialy Gbele Ouattara;Baco Traore;Ziandjêdé Hervé Siagné;Aboubacar Denon;Souleymane Sangare;Marc Ephrem Allialy(Laboratoire des Sciences Gographiques, du Gnie Civil et des Gosciences, Institut National Polytechnique Flix HOUPHOUT-BOIGNY (INP-HB), Yamoussoukro, Cte dIvoire;EUREKAGEO Sarl Consulting Mining Company, Bamako, Republic of Mali;Unit de Formation et de Recherche des Sciences de la Terre et des Ressources Minires (UFR-STRM), University of Cocody, Abidjan, Cte dIvoire)

机构地区：[1]Laboratoire des Sciences Gographiques, du Gnie Civil et des Gosciences, Institut National Polytechnique Flix HOUPHOUT-BOIGNY (INP-HB), Yamoussoukro, Cte dIvoire [2]EUREKAGEO Sarl Consulting Mining Company, Bamako, Republic of Mali [3]Unit de Formation et de Recherche des Sciences de la Terre et des Ressources Minires (UFR-STRM), University of Cocody, Abidjan, Cte dIvoire

出　　处：《Open Journal of Geology》2024年第6期655-670,共16页地质学期刊（英文）

摘　　要：Post-Neoproterozoic dolerites from the Kéniéba region (Western Mali) are often associated with kimberlites. The rarity of kimberlite outcrops led to the study of doleritic rocks, spatially associated with them. The petrographic and lithogeochemical study showed that the dolerites of the Kéniéba kimberlitic fields are of tholeiitic nature and of the E-MORB (Enriched-Mid Ocean Ridge Basalt) type. This reflects an enrichment over time, compared to the Birimian dolerites of the volcano-sedimentary greenstone belt of Toumodi, in central C?te d’Ivoire. Furthermore, these dolerites are enriched in SiO2, TiO2, Zr and poor in Fe2O3, MgO. These dolerites would have formed in a late to post-orogenic intracontinental context during the breakup of Gondwana. Structurally, Kéniéba dolerites are often associated with kimberlite pipes, fractures and large deep structures identified using aeromagnetic images. Taking into account the fact that kimberlites do not outcrop in the Kéniéba region, the geochemical study coupled with the interpretation of aeromagnetic data proved to be very useful for the search for pipes.Post-Neoproterozoic dolerites from the Kéniéba region (Western Mali) are often associated with kimberlites. The rarity of kimberlite outcrops led to the study of doleritic rocks, spatially associated with them. The petrographic and lithogeochemical study showed that the dolerites of the Kéniéba kimberlitic fields are of tholeiitic nature and of the E-MORB (Enriched-Mid Ocean Ridge Basalt) type. This reflects an enrichment over time, compared to the Birimian dolerites of the volcano-sedimentary greenstone belt of Toumodi, in central C?te d’Ivoire. Furthermore, these dolerites are enriched in SiO2, TiO2, Zr and poor in Fe2O3, MgO. These dolerites would have formed in a late to post-orogenic intracontinental context during the breakup of Gondwana. Structurally, Kéniéba dolerites are often associated with kimberlite pipes, fractures and large deep structures identified using aeromagnetic images. Taking into account the fact that kimberlites do not outcrop in the Kéniéba region, the geochemical study coupled with the interpretation of aeromagnetic data proved to be very useful for the search for pipes.

关 键 词：DOLERITES Kimberlitic Fields PETROLOGY Structures Kéniéba MALI 

分 类 号：P58[天文地球—岩石学]