Barred Olivine Chondrule from Ordinary Chondrite Meteorite

Contributed by Anthony Love, Laboratories Manager, Department of Geology, Appalachian State University.

Image 1A is CL image of a barred olivine chondrule. The image shows the barred olivine crystals in red that occur in a Na-rich glass. You can see several things highlighted by the CL. 1. The olivine exhibits normal zoning with the outer rim of the crystal being more Mg-rich while the inner portion of the crystal is more enriched in Fe (as it has a slightly darker hue of red).

2. We also see the chondrule, which should be spherical (circular in cross-section) has an igneous rim that gives it a slightly different outline. The rim is not zoned like the crystals that make up the barred olivine chondrule. This rim also appears to be composed of 2 different MgO contents of olivine as well.

3. There is an additional dusty rim on top of the igneous rim composed of yet another chemistry of olivine that may be more Fe-rich (but <5wt% FeO).

Image 1B is ordinary transmitted light image.