Zr-Y-U stratigraphy of the kakortokite-lujavrite sequence, southern Ilímaussaq intrusion

Abstract

The kakortokite-Iujavrite sequence in the southern part of the Ilimaussag intrusion has been subdivided on a number of field and hand-specimen criteria (Bohse & Andersen, 1981). The sequence is thought to represent a single pulse of magma except for the final, volumetrically insignificant intrusion of M-C lujavrite. In the present work, Zr, y and U data on the kakortokite-Iujavrite sequence are presented. The primary aim of the geochemical survey was to see if the field divisions could be confirmed. To this end, we analysed about 200 representative samples by reconnaissance X-ray fluorescence (XRF) techniques for the elements Zr, Y, Rb, Sr, Pb, Zn, Mn, Fe, La, Ce and Nd.