GEOCHEMISTRY AND GENESIS OF LAMPROITES OF THE ALDAN SHIELD

The paper summarizes the data on geochemistry and genesis of 14 occurr ences of lamproite in the Aldan shield. The data for 4 of them are giv en for the first time. Five facies have been distinguished amongst the most-studied lamproites of the Murun massif. Composition of lamproite mica from Aldan and the trace element abundances are presented. Corre lation of the abundances of elements of petrogenetic significance demo nstrate that Aldan lamproites are compositionally similar to lamproite s found elsewhere in the world. Data on the trace and rare earth eleme nt abundances in the Aldan lamproites are provided. Similar evolutiona ry trends of the Aldan lamproite compositions and those of the associa ted rocks of the K-alkaline complexes suggests that they are genetical ly related. Considering the isotopic characteristics of Nd, Sr and Pb the Aldan lamproites are similar to lamproites from North America. The isotope data indicate a deep mantle origin of the Aldan lamproites.