The origin of refractory precursor components of chondrules

Abstract

A percentage of all chondrules from carbonaceous chondrites are intermediate in major-element composition between the rare Ca,Al-rich chondrules and the more abundant ferromagnesian chondrules. Some of them possess fractionated REE and trace-element patterns similar to those in CAI's (Ca-Al-rich inclusions). The abundance patterns are controlled primarily by volatilities expected from a solar composition. On the basis of refractory lithophile fractionations, it is suggested that one of the refractory precursors of C chondrules is a condensate from the nebular gas or an evaporative residue of primitive dust clumps.