Nebular history of amoeboid olivine aggregates

作者:Sugiura N*; Petaev M I; Kimura M; Miyazaki A; Hiyagon H
来源:Meteoritics & Planetary Science, 2009, 44(4): 559-572.
DOI:10.1111/j.1945-5100.2009.tb00751.x

摘要

Minor element (Ca, Cr, and Mn) concentrations in amoeboid olivine aggregates (AOAs) from primitive chondrites were measured and compared with those predicted by equilibrium condensation in the solar nebula. CaO concentrations in forsterite are low, particularly in porous aggregates. A plausible explanation appears that all equilibrium Ca activity was not maintained during the olivine condensation. CaO and MnO in forsterite are negatively correlated, with CaO being higher in compact aggregates. This suggests that the compact aggregates formed either by a prolonged reheating of the porous aggregates or by condensation and aggregation of forsterite during a very slow cooling in the nebula.

  • 出版日期2009-4