- 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 Kierra complex in the southern Meru district, Kenya, comprises norites and hyperites in its lower parts, and some gabbro, which is frequently rich in hornblende. The upper part comprises anorthositic types. Pyroxenites occur sporadically in the basic series, and form distinct masses in the northeast and southeast. The age of the plutonic rocks is post-Archean and may be pre-Cambrian.