CHAPTER ONE INTRODUCTION 1.1 General Statement The Nigerian sector of  the Chad  Basin, known locally as the  Bornu Basin,  is one of  Nigeria’s inland basins occupying the northeastern part of the country. It represents about one-tenth of the total area extent of the Chad Basin, which is a regional large structural depression common to five countries, namely, Cameroon, Central African Republic, Niger, Chad, and Nigeria. The Bornu Basin falls between latitudes 110N and 140N and longitudes 90E and 140E, covering Borno State and  parts  of  Yobe  and  Jigawa  States  of  Nigeria.  The  Chad  Basin  belongs  to  the  African Phanerozoic sedimentary basins whose origin is related to the dynamic process of plate divergence. It is an intracratonic inland basin covering a total area of about 2,335,000 km2 with Niger and Chad Republics sharing more than half of the basin. The basin belongs to a series of Cretaceous and later rift basins in Central and West Africa whose origin is related to the opening of the South Atlantic (Obaje et al., 2004). In Nigeria, other inland basins of the same series include the Anambra Basin, the Benue Trough, the Mid-Niger (or Bida) Basin and the Sokoto Basin. The Nigerian sector of the Chad Basin, known locally as the Bornu Basin represents about one-tenth of the whole basin. It constitutes the southeastern sector of the Chad Basin.