OSM 015 (LL3.9-4)
Classification led by Cesca Willcocks
This meteorite belongs to Sean Mahoney.
This meteorite will possibly receive an official name of '***' - to be confirmed by the Nomenclature Committee of the Meteoritical Society.
The type specimen (***) will be on deposit at the University of Plymouth, along with a single, polished thin section.
A Variety of Chondrules
Chondrules are round, igneous-textured particles that are the characteristic features of chondritic meteorites. These can be widely grouped into two different types: Porphyritic and non-Porphyritic, with many sub-types within each group. We found a host of different chondrule types inside OSM 015! Here are some of the many chondrules we have been able to find during our analysis of OSM 015.
Layered image of a porphyritic olivine chondrule in OSM 015, where green is olivine and dark blue is plagioclase.
Porphyritic chondrules are identified by their large grains of olivine and/or low-Ca pyroxene, surrounded by a fine grained or glassy plagioclase matrix. These chondrules can also be broken down into iron-rich and iron-poor types depending on their iron content. In OSM 015, we found Porphyritic Olivine (PO) chondrules (where their large grains are olivine in compositions), as well as Porphyritic Pyroxene (PP) chondrules, where their large grains are pyroxene in composition. We also found Porphyritic Olivine-Pyroxene chondrules, where the larger grains comprised of both olivine and pyroxene.
Non-porphyritic chondrules are less common than porphyritic chondrules and can also be broken down into a number of groups. These include crypto-crystalline chondrules (lacking in any crystal structure) and radial pyroxene chondrules (made up of low-Ca pyroxene that radiates from a point near the rim of the chondrule). In OSM 015 we found many radial pyroxene chondrules, in particular the one displayed on the right that exhibits thin, low-Ca pyroxene grains radiating from the left side of the chondrule.
Layered image displaying a radial pyroxene chondrules, where the lighter teal is low-Ca pyroxene and the dark blue it plagioclase.
Layered image of a non-porphyritic, radial pyroxene chondrule where light teal is low-Ca pyroxene and dark blue is plagioclase.
Layered image of a porphyritic olivine-pyroxene chondrule, where green is olivine, light teal is low-Ca pyroxene and dark blue is plagioclase. This chondrule also has a large grain of apatite (red) in it's centre.
Layered image of a porphyritic pyroxene chondrule,, where light teal is low-Ca pyroxene and dark blue is plagioclase.