( ., 1967) , . , (. . 4, . 6.) 1,4 10-5 /, 5 10-10 /. , , 3-4 .

(Mg). , . MgO 33,60%. , (. 7). (Williams, 1932; Chesley, 1942; , , 1960; , , 1961; Bunting, Valkenburg, 1958; Raal, 1957 .). 30 29