A record of low-temperature asteroidal processes of amoeboid olivine aggregates from the Kainsaz CO3.2 chondrite

Amoeboid Olivine Aggregates in the Yamato-86009 Cv3 Chondrite

Fagan, M. Miyamoto, A.N. Krot and T. Mikouchi, The University Museum, University of Tokyo, 7-3-1 Hongo Bunkyo-ku Tokyo, Japan ([email protected]), Department of Earth Sciences, School of Education, Waseda University, 1-6-1 Nishiwaseda Shinjuku-ku Tokyo, Japan, Department of Earth & Planetary Science, University of Tokyo, Japan. Hawaii Institute of Geophysics and Planetology, University o...

FIRST Ti-XANES ANALYSES OF OLIVINE IN AMOEBOID OLIVINE AGGREGATES

Amoeboid Olivine Aggregates in CR Chondrites

Introduction: Amoeboid Olivine Aggregates (AOAs) are irregular-shaped, fine-grained aggregates of olivine and refractory minerals and are important components of C chondrites. The AOAs in CV chondrites have been interpreted to be primary nebular condensates [1] and therefore, can provide constraints on models for nebular condensation. AOAs are intermediate in composition, and may be a link, bet...

A Pristine Amoeboid Olivine Aggregate Protolith from the Vigarano Cv3 Chondrite

Introduction: Amoeboid olivine aggregates (AOA) are irregularly shaped inclusions found within all carbonaceous chondrites except CI [1,2]. Their bulk compositions are intermediate between those of anorthite-rich (Type C) calcium-aluminium rich inclusions and chondrules [2], and consist mostly of fine-grained olivine plus enclosed refractory nodules of spinel, pyroxene, feldspathoids, Fe-Ni met...

Examination of High Temperature Annealing of Amoeboid Olivine Aggregates: Heating Experiments of Forsterite and Anorthite Mixtures

Introduction: Amoeboid Olivine Aggregates (AOAs) are irregularly-shaped, 100 µm to 5 mm in size, fine-grained objects that constitute a few vol% of meteorites in most carbonaceous chondrite groups. Previous studies concluded that AOAs are aggregates of solar nebula condensates which continued to react with the solar nebula vapor to the temperature to form phyllosilicates. However, these studies...