Gravity Modelling and Structural Characterization of the Korosi–Chepchuk Geothermal Fields in Baringo, Kenya

Exploration and exploitation of geothermal resources is a very high-risk venture with high upfront costs. Hence, a clear understanding of the subsurface structural controls is more important in the development of a geothermal system. In this study, gravity data was processed to remove all the variations which do not result from the effects of underlying masses. Using the Golden Surfer Software, a grid and bouguer anomaly map was generated. To separate regional and residual anomalies and also remove effects of noise, the gridded data in Geosoft Oasis Montaj Software was subjected to band pass filter, high pass filter, upward continuation and both first order vertical and horizontal derivatives. The respective anomaly maps were plotted and analyzed. Finally, a gravity profile was obtained across the anomaly and 2D forward modelling performed. From the analysis, it was observed that there were two peaks, one at the Korosi and other at Chepchuk which are interpreted as the magma intrusions appearing at the depth of approximately 3km. Linear gravity gradients were also detected trending NE-SW direction which are possibly the Nakaporon and Nagoreti faults. Two target wells expected to be more productive in the area could be decided.