[1]Department of Earth Sciences Faculty of Sciences University of Douala Douala 2415 7 Cameroon;
[2]Department of Earth Sciences Faculty of Sciences University of Yaounde 1 Yaounde 812 Cameroon;
[3]Department of Mines Ministry of Mines lndustry and Technological Development Yaounde 70 Cameroon;
[4]Seismology Laboratory of Ekona Geophysics and Volcanic Research Department Institute of Mining and Geological Research Buea 370 Cameroon;
[5]Department of Geology and Environmental Science Economic Geology Unit University ofBuea Buea 63 Cameroon;