EarthRef.org Reference Database (ERR) -- Vinogradov 1956

The total chemical composition of the principal rock types has been subjected to a critical examination, namely the chemical composition of: 1) ultrabasic rocks (dunites, peridotites, pyroxenites); 2) basic rocks (gabbros, basalts, diabases, norites etc.); 3) intermediate rocks (andesites and diorites); 4) acid rocks (granites, rhyolites, ziparites etc.) as well as of the sedimentary rocks (clays and shales) and of the silicate phase of chondrites. For the principal constituents of the massive rocks, namely Si, Al, Fe, Ti, Mg, Ca, K, Na, P, Mn (and O) the weighted mean has been calculated according to Daly's, Nockold's, and the author's data (for the rocks of U.S.S.R.); for the clays and shales according to the data of Clarke, Hougen et al.; and according to the author's data for the clays of all ages of the Russian platform, etc. For all the other rarer and more scattered chemical elements average data (arithmetical) have been calculated on the basis of extensive known material (systematized in tables). The principal regularities in the distribution of chemical elements in rocks, being chiefly determined by the law of isomorphism, and the correlation of the chemical rock composition with the mineralogical composition have been considered. The identity of the silicate phase composition of chondrites and dunites is pointed out in detail. In comparing the clay + shale composition with granites, attention is attracted by the high content of Cr, Ni, Co, V, Cu and a number of other chemical elements in the sediments compared to granites. That is of particular interest in connection with the idea of the granitization process. The average composition of the earth's crust practically for all elements equals the composition of the mixture - 2 parts of granites + 1 part of basalts. A resulting table of the above mentioned rocks is given.