Temperature conditions for chondrule formation

Abstract

An attempt is made to constrain the chondrule-forming process from dynamic crystallization experiments on chondrule analogs and from correlations between texture and bulk composition in natural chondrules. Liquidus temperatures for chondrules from unequilibrated chondrites are calculated using Herzberg's (1979) method. The paper then infers whether each chondrule formed above, at, or below its liquidus based on textures produced in experiments. A range of temperatures to which chondrules may have been initially heated is then derived from the texture-composition-temperature relationships. Finally, the role of dust seeding, or external heterogeneous nucleation, in producing chondrule textures is examined.