Sample Petrographic Description
Sample Number | LAP 031214 |
Newsletter | 29,1 |
Location | LaPaz Ice Field |
Field Number | 16820 |
Dimensions (cm) | 3.0 x 2.0 x 2.0 |
Weight (g) | 9.50 |
Original Classification | CM1-2 Chondrite |
Updated Classification | CM2 Chondrite |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 1-41 | |
Weathering | |
B | |
Fracturing | |
B | |
Macroscopic Description - Kathleen McBride | |
Thick purple-black fusion crust covers 40% of the exterior. Polygonal fractures are visible. The interior is a dark gray to black matrix with an oxidation rind. | |
Thin Section Description (,2) - Tim McCoy, Linda Welzenbach | |
The sections consist of a few isolated mineral grains in a black matrix; rare metal and sulfide grains are present. Olivine compositions are Fa1-41. The meteorite is a CM chondrite and is intermediate between type 1 and type 2. | |
Reclassification Notes (AMN 46,2) | |
Bates et al. (2020) implies that LAP 031166 is the same as LAP 02277 and that both are CM1, based on XRD measurements of high phyllosilicate content. |
Antarctic Meteorite Images for Sample LAP 031214 | ||||
Lab Photo(s) : | ||||
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Antarctic Meteorite Images for Sample LAP 031214 | ||||
Thin Section Photo(s) : | ||||
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References for Sample LAP031214 | |
Sridhar, S., Bryson, J. F, King, A. J., & Harrison, R. J., 2021, Constraints on the ice composition of carbonaceous chondrites from their magnetic mineralogy. Earth and Planetary Science Letters, 576, 117243. | |
Bates, H.C., King, A.J., Donaldson Hanna, K.L., Bowles, N.E., Russell, SS., 2020, Linking mineralogy and spectroscopy of highly aqueously altered CM and CI carbonaceous chondrites in preparation for primitive asteroid sample return. Meteoritics & Planetary Science, 55, 77–101, doi: 10.1111/maps.13411. | |
Hanna, R.D., Hamilton, V.E., Haberle, C.W., King, A.J., Abreu, N.M., and Friedrich, J.M., 2020, Distinguishing relative aqueous and heating among CM chondrites with IR spectroscopy. Icarus, 346, 113760, doi: 10.1016/j.icarus.2020.113760. | |
Friedrich, J. M., Abreu, N. M., Wolf, S. F., Troiano, J. M., & Stanek, G. L., 2018, Redox-influenced trace element compositional differences among variably aqueously altered CM chondrites. Geochimica et Cosmochimica Acta, 237, 1-17. | |
King, A. J., Schofield, P. F., & Russell, S. S. , 2017, Type 1 aqueous alteration in CM carbonaceous chondrites: Implications for the evolution of water?rich asteroids. . Meteoritics & Planetary Science, 52, 1197-1215, doi: 10.1111/maps.12872. |