Sample Petrographic Description
| Sample Number | MIL 07687 |
| Newsletter | 32,1 |
| Location | Miller Range |
| Field Number | 18659 |
| Dimensions (cm) | 1.5 x 2.0 x 1.0 |
| Weight (g) | 5.49 |
| Original Classification | CO3 Chondrite |
| Updated Classification | C2 Chondrite Ungrouped |
| Mineral Composition (%Fa & %Fs) | |
| Fayalite (mol%): 1-50;Ferrosilite (mol%): 3-41 | |
| Weathering | |
| Ce | |
| Fracturing | |
| A/B | |
| Macroscopic Description - Kathleen McBride | |
| 90% rough brown/black fusion crust with polygonal fractures covers the exterior surface. The interior is a fine grained brown/black matrix with evaporites. The meteorite has a rusty oxidation rind and small (mm sized) rust colored chondrules are visible. | |
| Thin Section Description (,3) - Tim McCoy, Linda Welzenbach | |
| The section consists of abundant small (up to 1 mm) chondrules, chondrule fragments and mineral grains in a dark matrix. Metal and sulfide occur within and rimming the chondrules. Olivine ranges in composition from Fa1-50, with a strongly bimodal distribution (Fa0-1 and Fa40-50). Two pyroxene analyses range from Fs3-41. The meteorite is a CO3 chondrite. | |
| Reclassification Notes (AMN 41,1) | |
| (Davidson et al., 2015; Brearley, 2014) | |
| Notes | |
| Added to Special list at Fall 2017 meeting due to its unusual properties - may be an anomalous CO3 that has variable amounts of aqueous alteration (see Davidson et al., 2014 abstracts, and Brearley et al., 2012 and 2013 abstracts). | |
| Antarctic Meteorite Images for Sample MIL 07687 | ||||
| Field Photo(s) : | ||||
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| Field photo image(s) courtesy of the ANSMET (ANtarctic Search for METeorites) Program, Case Western Reserve University and the University of Utah | ||||
| Antarctic Meteorite Images for Sample MIL 07687 | ||||
| Lab Photo(s) : | ||||
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| Antarctic Meteorite Images for Sample MIL 07687 | ||||
| Thin Section Photo(s) : | ||||
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| References for Sample MIL07687 | |
| Prestgard, T., Bonal, L., Eschrig, J., Gattacceca, J., Sonzogni, C., and Beck, P., 2021, Miller Range 07687 and its place within the CM-CO clan. , Meteoritics & Planetary Science, 56 , 1758–1783 , doi: 10.1111/maps.13736 . | |
| Haenecour, P., Floss, C., Brearley, A.J., and Zega, T.J., 2020, The effects of secondary processing in the unique carbonaceous chondrite Miller Range 07687. , Meteoritics & Planetary Science, 55 , 1228-1256 , doi: 10.1111/maps.13477. | |
| Davidson, J., Alexander, C. M. D., Stroud, R. M., Busemann, H., & Nittler, L. R., 2019, Mineralogy and petrology of Dominion Range 08006: A very primitive CO3 carbonaceous chondrite. , Geochimica et Cosmochimica Acta, 265 , 259-278 . | |
| Bonal, L., Quirico, E., Flandinet, L., Montagnac, G., 2016, Thermal history of type 3 chondrites from the Antarctic meteorite collection determined by Raman spectroscopy of their polyaromatic carbonaceous matter. , Geochimica et Cosmochimica Acta, 189 , 312-337 . | |
| RELAB, , Reflectance Experiment Lab , catalogue of samples, . | |