The West and Central African Rift System (WCARS) is a

rift system In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben wi ...

composed of two coeval

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

rift sub-systems, the West African Rift sub-system (WAS) and the Central African Rift sub-system (CAS). These are genetically related, but are physically separated and show structural differences. The Logone Birni Basin constitutes a transitional area between the two sub-systems. The WCARS is older than the

East African Rift System East or Orient is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth. Etymology As in other languages, the word is formed from the f ...

References

Mesozoic rifts and grabens Structural geology Plate tectonics Cretaceous geology {{africa-geo-stub