CRUSTAL TOMOGRAPHY OF THE CENTRAL KENYA RIFT

During the Kenya Rift International Seismic Project 1990 (KRISP90) experiment the shots of the seismic refraction programme were recorded by a two-dimensional teleseismic network. This was installed in the central part of the Kenya Rift and on its shoulders, from Lake Baringo in the north to Lake Naivasha in the south. P-wave first arrivals were used to determine lateral crustal velocity heterogeneities with a three-dimensional inversion programme. Mainly high-velocity zones were found which can be correlated with other geophysical anomalies and geological features. This comparison shows that the high-velocity bodies found within the crust are likely indicators for mafic cumulates or magma chambers. These evolved during the major magmatic episodes which are typical indicators for an active rift.