Thermal and geodynamic setting of the Buem volcanic rocks near Tiélé, Northwest Bénin, West Africa

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• 作者：Affaton ; Pascal ; Aguirre ; Luis ; Mé ; not ; René ; -Pierre
• 关键词：Bé ; nin ; Extensional tectonic ; Mafic volcanism ; Pan-African orogeny ; Pumpellyite ; Trace elements ; Very low-grade metamorphism ; West-Africa
• 刊名：Precambrian Research
• 出版年：1997
• 出版时间：April, 1997
• 年：1997
• 卷：82
• 期：3-4
• 页码：191-209
• 全文大小：1.34 M

文摘

The mafic volcanic rocks of Tiélé occur as intercalations within very low-grade metasediments, mainly metapelites and meta-arenites. These Proterozoic supracrustal rocks are considered as part of the Buem Structural Unit (BSU) which is the most external tectonic unit of the Pan-African Dahomeyide fold belt. The geodynamic significance of the BSU is still debated: it could represent either a portion of the West-African passive margin during the rifting and the drifting of the Pan-African ocean (Affaton, 1990), or a continental rift-zone (Jones, 1990) or the Pan-African oceanic crust itself (Burke and Dewey, 1972 and Burke and Dewey, 1973; Shackleton, 1976).