Volatile-rich chondrules in the Allende meteorite

A new type of chondrules in the Allende meteorite is rich in volatile elements and shows porphyritic textures similar to terrestrial basalts. This unique type is termed Type V to supplement H. Y. McSWEEN\u27S (Geochim. Cosmochim. Acta, 41,1843,1977) classification of chondrules in carbonaceous chondrites. The Type V chondrules form a continuous trend with the Type I and II chondrules in the (Na+K)-(Al)-(Si) and (Na+K)-(Al+Ca)-(Mg+Fe) ternary systems. Type IV is plotted between Type V and CAI\u27s. These compositional features of the different types of chondrules suggest that Type V was resulted from a fractionation process in the precusor materials of the Allende meteorite