- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
"The distribution of Tertiary to Recent lavas in part of south-west Kenya is outlined, and attention drawn to the predominance of nepheline-rich Miocene lavas over other types west of the rift valley, which contrasts with the Pliocene olivine basalt-trachyte-comendite association predominating within the rift valley. It is inferred that widespread Miocene phonolites west of the rift valley derived from a parent of approximate melanephelinitic composition, while within the rift valley extensive Pleistocene trachytes differentiated from an olivine basaltic parent. . . . The frequent association of nephelinitic lavas and carbonatite complexes in Kenya is discussed and the possibility mooted that the presence of nephelinite lavas may be indicative of nearby carbonatite complexes."