The Menengai Caldera Structure and its Relevance to Geothermal Potential

Abstract

Calderas are considered to be depressions resulting from an underpressure and/or overpressure within the magma chamber and can be used to interprete the conditions of the subsurface. Menengai caldera is located on the floor of the Kenya Rift Valley, 24 km south of the equator and is seen to be of great geothermal potential. Its location on major structures the Molo and Solai TVA is percieved to be advantageous in terms of a highly productive, high temperature geothermal system. Hot spots in the Menengai area further indicate that the system is still active. Various findings project thatthe caldera has undergone multiple block collapse and is thus classified as a piecemeal caldera. The stages of its development include pre caldea volcanism, caldera susidence, post caldera volcanism and hydrothermal activity. The structure of the caldera and post caldera volcanism and hydrothermal alteration imply a shallow and active magma chamber respectively.