TITLE:
Tectonic Style Associated with the Doleritic Dykes of the Téra-Ayorou Pluton (Liptako, Western Niger)
AUTHORS:
Kamayé Tourba, Gambo Ranaou Noura, Abdou Dodo Bohari, Karimou Dia Hantchi, Mallam Mamane Hallarou, Hassane Ibrahim Maharou, Yacouba Ahmed, Moussa Konaté
KEYWORDS:
Dolerite Dykes, Associated Structures, Deformation Phases, North Liptako, Niger
JOURNAL NAME:
International Journal of Geosciences,
Vol.15 No.8,
August
26,
2024
ABSTRACT: The doleritic dykes present in the Téra-Ayorou pluton crosscut the basement of the Nigerien Liptako and are part of the system of intrusive mafic dykes in the Paleoproterozoic domain of the Léo-Man ridge. In the previous work, emphasis was placed on the petrology, geochemistry and geochronology of the Liptako doleritic dykes. This study aims to analyze the tectonic style of intrusive doleritic dykes in the Téra-Ayorou pluton. The characterization of the deformation which affected the doleritic dykes of the Téra-Ayorou pluton is important for the evaluation of their economic potential. To this end, measurements of tectonic structure planes were taken in the field, and samples were taken from the chilled margin and cores of dolerite dykes, before being processed in the laboratory. Analysis of the tectonic structures collected revealed a brittle tectonic pattern, characterizing a phase of deformation subdivided into two episodes D1 and D2. Episode D1, with its subvertically dipping normal faults and simple N70˚ - N110˚ fractures, is compatible with N-S extension. On the other hand, episode D2, which created shear corridors by reactivation of pre-existing fractures and oriented N150˚ - N170˚, is associated with a WSW-ENE extension. These results open up prospects for the exploration of gold, uranium mineralization and diamonds in the north-west of Niger.