BO - Barred Olivine Chondrules

Barred chondrules are believed to have formed from completely melted droplets with fast cooling but some researchers make the case for one or more condensation scenarios.

When a BO chondrule is cut the plates appear as bars in the plane of the section. In the classic bared chondrule they are in optical continuity with each other and with the adjacent chondrule shell. A polysomatic chondrule has more than one set and may present a remarkable symmetry in thin section. The plane through which a barred chondrule is cut for viewing affects what we see. If the section makes only a shallow incursion into the sphere any rim will look disproportionately wide. If the plane of the plates is met at a shallow angle it will appear that there are few plates and that they are thick.

Pyroxene, too, is found with a barred texture.

Cole Creek H5


Mount Tazerzait L5 Anomalous


Selma H4


Dalgety Downs L4


DaG 467 L6