Notes on the fractionation of some of the abundant lithophile elements in chondrites with particular reference to Ca and Al

Abstract

Fractionation of the abundant lithophile elements Al, Ca and Mg relative to Si between (i) carbonaceous chondrites, (ii) common chondrites plus amphoterites and (iii) enstatite chondrites has been examined. Only the analytical data of Wiik have been used. Although the analytical data on Al and Ca, particularly in the enstatite chondrites are not entirely satisfactory for fractionation studies of this kind, it is clear that fractionation of each element has taken place. The degree of fractionation however varies widely. For example, the ratio Si/Mg increases only by 10% when passing from the carbonaceous to the common chondrites, whereas that of Si/Ca increases by about 50%.