Before filling out the request form below, refer to our most recent specimen catalogue, and read the following conditions regarding the process of sample request:

1. Only requests made by researchers at established, accredited institutions will be considered.
   Students seeking samples for graduate research must have their advisor fill out and submit the sample request form. Granted samples will be the responsibility of the advisor.
2. Loans are issued for 6 months with the possibility of extension if requested by the researcher prior to the loan return date. Extensions to the loan period must be approved by the repository curator.
3. Unused portions of specimens issued for destructive analysis must be returned with a detailed description of analysis methods or reagents to which they were exposed. Please download, fill in, and return the Sample Return Form with your sample(s).
4. Permission must be obtained before polished or thin sections are made from loaned samples. If permission is granted, the repository remains the owner of any sections prepared from the original sample.
5. Loans shall not be transferred by the borrower to any other institution or individual without prior written approval.
6. Presentations, abstracts, and published papers with results from research conducted on UACh samples must acknowledge the repository and refer to the meteorite specimen in both name and catalog number. A copy of the abstract or paper should be send to us for our records.

We recently discovered two achondrites in the North of Chile: an ureilite from the Calama area in the Antofagasta region and an howardite officially named as Cariquima from the Tarapaca region. See a more detailed description and some pictures below.

Cariquima

The Cariquima howardite shows a fresh glassy fusion crust on all sides and some flow lines. There is no evident weathering, suggesting a short time on the Earth's surface. Mass of the single specimen is 280 g.

Petrography: Cariquima is a polymict breccia of sub-mm/mm sized eucrite and diogenite clasts in a fine matrix of related crystalline debris with typical grain size less than 50 μm. Contains aprox. 70 wt% eucrite materials and 30 wt% diogenite materials (based on average Al and Ca contents of the fusion crust). Eucrite components are mostly lithic fragments of basaltic eucrite, with only some clasts of cumulate eucrite. These clasts vary in texture from fine-grained porphyritic to coarse-grained subophitic. One cumulate eucrite clast presents a variolitic texture. The eucrite materials typically contain exsolved ferroan pigeonite and plagioclase, as well as minor and accessory phases such as silica, ilmenite, chromite, troilite, metal, zircon, fayalitic olivine, apatite and merrillite. Diogenite components are essentially orthopyroxene fragments, some with thin chromite veins. Shock evidence include the presence of melt pockets and veins with quenched texture in some pyroxene and silica grains and darkening of pyroxene by small blebs of metal and troilite. One round chondrule-like chromite-plagioclase assemblage was also observed in the studied polished thick section.

Geochemistry: Pyroxene overall Fe/Mn (atomic) 29.8±3.1 (N=77). Diogenitic low-Ca pyroxene Fs_21.7±2.9Wo_2.1±0.7 (N=18), Ca-pyroxene Fs_16.6Wo_38.8 (N=1). Eucritic low-Ca pyroxene Fs_47.5±9.0Wo_5.7±3.2  (N=36), Ca-pyroxene exsolution lamellae Fs_33.7±12.4Wo_34.4±7.6 (N=12). Plagioclase An_87.8±4.8Ab_12.2±4.8 (N=42). Chromite Cr# = 0.77±0.06 (N=8).

Ureilite (not yet officially named)

Three meteorite fragments were found within half a meter of each other. They are highly consolidated desert polished rocks, which lack fusion crust. Two fits well together. Density is about 3.3 and total mass is 860 g. Individual masses are 615, 169 and 76 g. Sample cutting with a diamond blade was rather difficult, suggesting the presence of a hard component (diamond).

Thin section in cross-polarized transmitted light (above) and reflected light (below). Sample is 4 mm wide.

Petrography: One thin section examined. Sample dominated by fine to medium-grained (0.5-2 mm) interlocked anhedral-subhedral crystals of olivine (~50 vol.%) and pigeonite (~25 vol.%) with abundant 120º triple junctions and without preferred orientation. Olivine and pigeonite show reduced margins. An interconnected network of Fe hydroxides (~15 vol.%) containing rare kamacite and up to 20 µm thick occur along silicate grain boundaries. Fe hydroxides are also present as µm-size blebs (~5 vol.%) within silicate rims, mostly olivine. Interstitial aggregates of carbon material are also widespread (~5 vol.%). They reach up to 200 µm in size and Raman measurements indicate that they are mostly made of micrometric diamonds and graphite. No large graphite flakes were observed. Some pigeonite and olivine grains show weak undulatory extinction. Twinning is also observed in some silicate grains, mostly in pigeonite and rarely in olivine. Overall, weathering grade is moderate and shock grade is low to moderate.

Geochemistry: Olivine cores (N=10) Fa_21.3±0.7, FeO/MnO=40.2±3.9 (wt. ratio), Cr₂O₃=0.74±0.08 wt.%, CaO=0.33±0.05 wt.%. Olivine rims down to Fa2.5 and FeO/MnO= 5.4. Pigeonite cores (N=7) En_72.3±0.5Wo_9.8±0.2Fs_17.8±0.5, Cr₂O₃=1.3±0.1 wt.%, Pigeonite rims up to En_83.7. Kamacite 4.2 wt.% Ni.

Raman spectra showing the presence of interstitial diamond and graphite.

Peer-reviewed articles

• Tavernier A., Pinto G.A., Valenzuela M., Garcia A., Ulloa C., Oses R., Foing B.H. (2023) Trends in planetary science research in the Puna and Atacama Desert regions: Underrepresentation of local scientific institutions? Meteoritics and Planetary Science 58, 4, 516-528. DOI: 10.1111/maps.13972
• Pinto G.A., Marrocchi Y., Jacquet E., Olivares F. (2022). Formation of chondrule fine‐grained rims from local nebular reservoirs. Meteoritics & Planetary Science, 57(5), 1004-1017. DOI: 10.1111/maps.13812
• Pinto G.A., Marrocchi Y., Morbidelli A., Charnoz S., Varela M.E., Soto K., Martínez R., Olivares F. (2021) Constraints on Planetesimal Accretion Inferred from Particle-size Distribution in CO Chondrites. The Astrophysical Journal Letters 917, L25. DOI: 10.3847/2041-8213/ac17f2
• Zambardi T., Franck Poitrasson F., Corgne A., Méheut M., Quitté G., Anand M. (2013) Silicon isotope variations in the inner solar system: Implications for planetary formation, differentiation and composition. Geochimica et Cosmochimica Acta 121, 67–83. DOI: 10.1016/j.gca.2013.06.040
• Corgne A., Wood B.J., Fei Y. (2008) C- and S-rich molten alloy immiscibility and core formation of planetesimals. Geochimica et Cosmochimica Acta 72 (2008) 2409–2416. DOI: 10.1016/j.gca.2008.03.001.

Conference proceedings

• Pinto G.A., Marrocchi Y., Villeneuve J., Olivares F., Soto K., Corgne A., Luais B. (2022) The frequency of Fe-poor relicts in type II chondrules of carbonaceous and ordinary chondrites. 53rd Lunar and Planetary Science Conference. Abstract 2925.
• Pinto G.A., Marrocchi Y., Olivares F., Soto K., Varela M.E., Martínez R. (2021) Size-distribution of nebular components in CO3 Chondrites: Hits at an heterogeneous accretion history. 52nd Lunar and Planetary Science Conference. Abstract 1371.
• Tavernier A., Demarzo M.A.D., Merazina J.A.F., Pinto G., Ulloa C., Garcia A., Foing B.H. (2021) Exokite, designe of an aerial decision-support platform in an Martian inhabited space exploration context. 52nd Lunar and Planetary Science Conference.
• Valenzuela M., Oliveros V., Menzies A., Pinto G., Corgne A., Alvarez S., Beltrán T., Echevarría R., Revillard A., Salazar N., Soto K., Ulloa B. (2021) QEMSCAN® as a new tool for classification: First results in ordinary chondrites from Atacama Desert, Chile. 84th Annual Meeting of the Meteoretical Society. Abstract 6281.
• Cid J., Corgne A. (2018) Metamorfismo de choque del basamento plutónico del cráter de impacto de Monturaqui. Congreso Geológico Chileno, Concepción, Chile.
• Gómez F., Corgne A. (2018) ¿A bolide atmospheric airbust over Southern Chile during colonial times? Congreso Geológico Chileno, Concepción, Chile
• Echevarría R., Corgne A. (2018) Hacia una clasificación de los meteoritos AIUC-1 y AIUC-2. Congreso Geológico Chileno, Concepción, Chile.

Undergraduate Thesis (UACh)

• 2023. Katalina Vidal. Caracterización petrográfica y geoquímica de dos muestras de condritos ordinarios (MET17-02 y MET17-03) encontradas en el Desierto de Atacama.
• 2023. Lucas Gutiérrez. Caracterización petrológica de los clastos de la howardita Cariquima.
• 2023. Nicolás Cárcamo. Estudio petrológico, clasificación y origen de las muestras AV-MO2B y AV-MO8B de meteoritos encontrados en el Desierto de Atacama, Chile.
• 2022. Katherine Neumann. Clasificación petrográfica y geoquímica de los meteoritos MV-088 Y MV-039 encontrados en el Desierto de Atacama, Chile.
• 2021. Francisco Gómez. Investigación de las evidencias geológicas asociadas al posible evento de explosión de un meteoroide en las Islas Guaitecas reportado en manuscritos históricos de la colonia.
• 2020. Kevin Soto. Caracterización petrológica y origen de dos meteoritos encontrados en el Desierto de Atacama, Chile.
• 2020. Rodrigo Echevarría. Clasificación de los meteoritos del Atacama Taltal 001 y San Juan 086 representados en las muestras AIUC-01 Y AIUC-02.

Articles

Pinto, G., Flores, L., Martínez, R. (2020). Museos interactivos de ciencia y la alfabetización científica: Rol del Museo del Meteorito. Ápice. Revista de Educación Científica, 4(2), 63-72. DOI: 10.17979/arec.2020.4.2.5829

Asteroid Day conferences

2016

2017

2018

Talks

Specialists - Sociedad Geológica de Chile

The persons behind the UACh repository are:

• Dr. Alexandre Corgne. Associate profesor UACh. Research areas include the study of planetary interiors using experimental petrology and geochemistry.
• Dr. Gabriel Pinto. Early-career planetary scientist studying the conditions of formation and agglomeration of chondrules in the early Solar System.
• Dr.(c) Kevin Soto. Early-career researcher studying the thermal history of carbonaceous chondrites.

Collaborators include:

• Dra. Millarca Valenzuela (Universidad Católica del Norte, Chile).
• Dr. Jérôme Gattacceca (CEREGE, France)
• Mr. Nicolás Cárcamo. Geologist. Undergraduate thesis and other projects focused on the classification and weathering of ordinary chondrites. Currently studying a newly recovered ureilite.
• Mr. Rodrigo Martínez. Museo del Meteorito, San Pedro de Atacama, Chile.