Seismic and Gravity Surveys in the Lake Baringo–Tugen Hills Area, Kenya Rift Valley

By using seismic and detailed geological data from a region of the KenyaRift where a complete Caenozoic rock sequence is exposed, it has been possible to interpret the gravity data and produce density models of a somewhat greater degree of uniqueness than has previously been possible. The configuration of the dense rocks responsible for the ‘axial high’ gravity anomalies is still not well defined but they seem to form a broad (20–35 km) zone within the basement, with strike along the Rift axis, and of limited average vertical extent (4–6 km). Such a model may imply a lopolith type of basic intrusion which would fit in with the small estimate of crustal extension across the Rift at this latitude which has been proposed. However, it is still possible to devise a dyke intrusion interpretation.