Sample Petrographic Description
Sample Number | LAP 031387 |
Newsletter | 29,2 |
Location | LaPaz Ice Field |
Field Number | 16593 |
Dimensions (cm) | 1.25 x 0.5 x 1.0 |
Weight (g) | 1.09 |
Original Classification | R Chondrite |
Updated Classification | R4 Chondrite |
Pairing | LAP 03639; LAP 031144; LAP 031387; LAP 03731; LAP 03793; LAP 03902; LAP 04845; |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 6-38;Ferrosilite (mol%): 1-30 | |
Weathering | |
B | |
Fracturing | |
A/B | |
Macroscopic Description - Cecilia Satterwhite | |
The exteriors of these R chondrites have brown/black fusion crust with some evaporites. The interiors are gray with some large light and dark inclusions. Some oxidation and rust is present. | |
Thin Section Description (,2) - Valerie Reynolds, Tim McCoy | |
The sections are so similar that a single description suffices. The sections consist of ~50% of well-defined, small (up to 1 mm) chondrules set in a slightly recrystallized matrix of silicates and sulfides (both troilite and pentlandite). Olivines are nearly homogeneous (Fa35-38, with a small tail of analyses down to Fa6) and pyroxenes exhibit a larger range (Fs1-30). The meteorites are R chondrites, probably of petrologic type 4. | |
Reclassification Notes (AMN 31,1) | |
Reclassified as R4 Chondrite in AMN 31,1. |
References for Sample LAP031387 | |
Bischoff, A., Vogel, N., Roszjar, J., 2011, The Rumuruti chondrite group. Chemie der Erde - Geochemistry, 71 Issue 2, May-11, 101-133, ISSN 0009-2819, http://dx.doi.org/10.1016/j.chemer.2011.02.005. |