1. Université Dan Dicko Dankoulodo de Maradi, Faculté des Sciences et Techniques, Département de Géologie, Maradi, Niger and China University of Geosciences, Ministry of Education, Key Laboratory of Tectonics and Petroleum Resources, Wuhan, China. (corresponding author)
2. China University of Geosciences, Ministry of Education, Key Laboratory of Tectonics and Petroleum Resources, Wuhan, China and China University of Geosciences, School of Earth Resources, Wuhan, China.
3. Université Abdou Moumouni, Faculté des Sciences et Techniques, Département de Géologie, Niamey, Niger.