- 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
Trace element analyses of tuffs, to identify certain elements typical of carbonatites, were first made of samples from Longido, Tanganyika. Later, tuffs and limestones from the Serengeti region were analyzed, and it was found that niobium and yttrium were present in the majority of specimens (22 of 24) and that lanthanum ranged from 50-600 ppm. From field and geochemical evidence, it is proven that carbonatitic volcanoes have ejected vast amounts of pyroclastic tuffs, calcareous tuffs, and limestones up to 100 miles from the vents. Trace element data are given.