|
Calama 024 | |||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Basic information | Name: Calama 024 This is an OFFICIAL meteorite name. Abbreviation: There is no official abbreviation for this meteorite. Observed fall: No Year found: 2017 Country: Chile Mass: 253 g | ||||||||||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 6775 approved meteorites (plus 6 unapproved names) classified as H6. [show all] Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||||||||||||||||||||
Comments: | Approved 14 Dec 2018 | ||||||||||||||||||||||||||||||||||||||
Writeup |
Writeup from MB 107:
Calama 024 22°27.549’S, 68°39.227’W Antofagasta, Chile Find: 19 Oct 2017 Classification: Ordinary chondrite (H6) History: Meteorite (252.95 g) was found 19 October 2017 by the UrFU meteorite expedition-2017 in Chile (Pastukhovich A.Yu., Larionov M.Yu., Kruglikov N.A., Kolunin R.N.) near Chiu-Chiu, Calama region. Physical characteristics: Total mass is 252.95 g. The meteorite has roughly rounded shape. Exterior of the stone is desert polished. The surface and interior of the meteorite is light to dark brown in color due to Fe-hydroxides. Fusion crust is locally preserved (up to 1 mm). Petrography: Classification (Victor V. Sharygin, SIGM and UrFU). Petrographic observation of a polished thin section shows chondrules in a coarse recrystallized matrix. Chondrules are poorly delineated and their sizes vary from 200 µm to 2 mm. The largest chondrules (1-2 mm) are visible macroscopically and represented by PO, POP and RP textural types. The PO and POP chondrules mainly consist of olivine, low-Ca-pyroxene and plagioclase, diopside, and ± chromite and metal-sulfide blebs. Some RP chondrules may contains SiO2 polymorph (10x100 µm) In addition to chondrules, a "refractory forsterite-rich object" (size - 300 µm, RFRO) was found. It consists of high-Mg forsterite and low-Ca pyroxene phenocrysts, and interstitial augitic clinopyroxene and An-rich plagioclase. Olivine, low-Ca-pyroxene and plagioclase are main minerals in the chondrite matrix. Clinopyroxene, chromite, chlorapatite and merrillite (50-300 µm) occur locally in the matrix. Plagioclase grains in the matrix are larger than 50 µm, indicating a petrologic type of 6 for the meteorite. The absence of opaque shock veins and weak undulatory extinction and irregular fractures in olivine indicate a shock stage of S2. Majority of grains of FeNi metal (kamacite, taenite, tetrataenite, up to 1 mm) and troilite (100-500 µm) are fresh. Pyrrhotite (Ni – 0.4 wt.%, up to 10 µm) occurs in outer parts of troilite. Grains of copper (up to 10 µm) were observed in kamacite-taenite-tetrataenite-troilite aggregates. Weathering products (goethite, Fe-Ni-Cl-hydroxides, Fe-chloride-hydrate and gypsum) occur as in situ partial alteration of FeNi-metals and troilite and fill microfractures in minerals from matrix and chondrules (weathering grade – W2). Rare Fe-Ni-hydroxides veins are crosscut the meteorite sample. Fusion crust consists of dendritic/skeletal magnetite and olivine and Fe-rich glass. Plagioclase near fusion crust is transformed into maskelynite. Fe-rich glass contains rare metal-sulfide blebs (5-10 µm). Geochemistry: EDS-WDS analyses (Victor V. Sharygin, SIGM and UrFU). The primary chondrite paragenesis includes olivine Fa19.73±0.36 (N=48), low-Ca pyroxene Fs17.24±0.26Wo1.22±0.25 (N=26), plagioclase Ab82.8An11.7Or5.5 (n=17), Cr-bearing clinopyroxene En47.3Fs7.2Wo45.5 (N=8, Cr2O3 – 0.87 wt.%), chromite Crt81.7Spl13.6 (N=12), merrillite, chlorapatite and FeNi-metals. Chemical variations in RFRO: olivine Fa4.9-20.3 (N=10), low-Ca pyroxene Fs3.1-3.6Wo0.3-0.4 (N=5), clinopyroxene En59.6-62.5Fs3.2-5.9Wo30.9-35.1 (Cr2O3 - 1.8-2.5 wt.%, Al2O3 – 3.3-5.0 wt.%, N=8), plagioclase An47.3Ab51.9Or0.8 (N=1). Merrillite in matrix is poor in FeO (0.6-0.9 wt.%, N=11). Chlorapatite contains F (up to 0.5 wt.%); Cl – 5.32 wt.%, Na2O – 0.5 wt.% (N=8). Composition of metals (in wt.%): kamacite (N=30) - Fe 93.46±1.78, Ni 6.10±1.78, Co 0.46±0.06; taenite (N=9) – Fe 67.25, Ni 32.55, Co 0.26; tetrataenite (N=6) – Fe 49.21, Ni 51.60, Co 0.15; copper (N=4) – Cu 92.66, Fe 5.05, Ni 2.33. Fe-chloride-hydrate (in wt.%): FeO 62.6, NiO 2.8, CoO 0.5, SO3 0.5, Cl 30.1. Classification: Ordinary chondrite. H6, S2, W2. Specimens: 213.8 g sample – UrFU; 32.51 g sample and thin section – SIGM | ||||||||||||||||||||||||||||||||||||||
Data from: MB107 Table 0 Line 0: |
|
||||||||||||||||||||||||||||||||||||||
Institutions and collections |
UrFU: Ural Federal University, 620002, 19 Mira street, Ekaterinburg, Russia (institutional address; updated 14 Jan 2015) SIGM: V.S. Sobolev Institute of Geology and Mineralogy SB RAS, pr. Akademika Koptyuga, 3 Novosibirsk, 630090, Russia; Website (institutional address; updated 10 May 2017) |
||||||||||||||||||||||||||||||||||||||
Catalogs: |
| ||||||||||||||||||||||||||||||||||||||
References: | Published in Meteoritical Bulletin, no. 107, MAPS 55, 460-462
| ||||||||||||||||||||||||||||||||||||||
Geography: |
Statistics: This is 1 of 3417 approved meteorites from Antofagasta, Chile (plus 12 unapproved names) (plus 1 impact crater) This is 1 of 3446 approved meteorites from Chile (plus 13 unapproved names) (plus 1 impact crater) | ||||||||||||||||||||||||||||||||||||||
Proximity search: | |||||||||||||||||||||||||||||||||||||||
Also see: |
This lists the most popular meteorites among people who looked up this meteorite.
| ||||||||||||||||||||||||||||||||||||||
Revision history: |
This lists important revisions made to data for this record.
|