THE PROBLEM OF THE CLASSIFICATION OF THE YAKUTIA KIMBERLITES(BASED ON THOSE OF THE ALAKIT-DALDYNSK DIAMANTIFEROUS REGION)

Abstract

“The writers associate the formation of kimberlite with the partial fusion of peridotites in zones of ultrahigh pressure and think that the inclusions in them are unmelted fragments of peridotite caught up by the kimberlite magma... kimberlites can be defined as fissure-filling formations in platform and quiescent folded areas. They are mostly hy -pabyssal intrusive rocks, but pyroclastic and probably effusive variants are also found. They form explosion pipes (diatremes) and, less often, dikes and other bodies [authors].” Several previously suggested classifications of kimberlites are evaluated and each is found to fall short of that needed. Thence, it is suggested that the kimberlites of the Alakit-Daldynsk Region, at least, can first be classified on the basis of composition of the matrix; whether mica-free or mica-bearing; second as to relative content of fragmental material: 1) massive (less than 25% fragmental material); 2) breccia-form (25-50% fragmental material); 3) breccias (greater than 50% fra...