Experimental studies of chondrules

Abstract

A series of dynamic crystallization experiments has been conducted with several chondrule compositions. The results obtained have demonstrated that the many heterogeneous nuclei control chondrule textures. The presence of a few nuclei thus leads to barred and radiating textures from melts at or above liquidus; several nuclei just below liquidus result in microporphyritic textures; and spherules cooled faster than 2000 C/hr develop more spherulitic or acicular crystals than those of typical chondrules. The dominance of granular textures in Mg-rich olivine chondrules, porphyritic textures in Fe-rich olivine chondrules, and radiating textures in Si-rich chondrules, indicates a common limit to the initial temperature.