HELIUM AND ARGON ISOTOPE ABUNDANCES IN ROCKS OF LOVOZERO ALKALINE MASSIF

He and Ar isotope abundances in alkaline rocks of the Lovozero layered ore-bearing complex are used to discuss the origin of hydrogen-hydroc arbon gases (HHG). Three procedures to extract - crushing, milling and melting - and the chemical analysis of these gases have been describe d, and then the isotope analysis of the ratios of He-3/He-4 and Ar-40/ Ar-36 is related. It is suggested, that (He-4/Ar-40)rad ratios and He- 4 concentrations decrease and He-3/He-4 increase with the distance fro m the ore zone, the former ratio being the most contrast indicator of ore mineralization. A direct correlation has been revealed between hel ium isotopic ratios and methane concentrations. The results of measure ments confirm the idea on the crustal origin of HHG.