The Sadiman volcano is younger than Lemagrut the products of which it overlaps. It is made up largely of nephelinitic tuffs and agglomerates. Subsidiary lavas include nephelinite, phonolitic nephelinite, melilite nephelinite, phonolitic trachyte and sodalite phonolite. Analyses of foidite and nepheline, including trace element and Sr, Nd and Pb isotope data, are in Paslick et al. (1995 and 1996). On the Eyasi Plateau north of Lake Eyasi and west of Lemagrut and Oldeani are extensive Pleistocene tuffs which probably erupted from the Sadiman volcano. These tuffs include the Laetoli Beds which preserve an extraordinary array of fossil footprints including those of early hominids. A stunning photograph of these ~3.5 million year old footprints will be found in Hay and Leakey (1982). Hay (1978) and Hay and O’Neil (1983) report that the upper unit of the Laetoli Beds contains approximately 25 carbonatite and 35 melilitite-carbonatite air-fall layers, the chemistry of which they describe.