High interest to basic-ultrabasic rocks is ex- plained by their specific, sutural, geotectonic po- sition and by deep level of generation of ultraba- sic magmas. These two factors allow us to treat this group of rocks as valuable source of informa- tion about the lower crust and upper mantle of the Earth. Basic-ultrabasic xenolith series is another source of information about the interior of the Earth. Detailed studies of the xenolith series give valuable material to geologists as to how endogenic deposits are fed and what is their source._x000D_
Besides, the interest is explained by attempts to understand the relationship between basic-ultra- basic complexes and deposits of metalliferous and non-metalliferous mineral material._x000D_
Absence of genetic boundaries in manifestation of metalliferous and non-metalliferous minerals, their temporal and spatial relationship allow us to treat the minerogenesis of ultrabasic complexes as a result of one ore-forming process manifested in Koryak-Kamchatsky, Sakhalin-Japanese, Ryukyu-Korean and Taiwan-Philippines island arc systems which re- present, in the opinion of the authors, one eastern Asian chain of the Pacific ore belt (Radkevich, 11)87).