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Malotas (c)
Basic information Name: Malotas (c)
     This is an OFFICIAL meteorite name.
Abbreviation: There is no official abbreviation for this meteorite.
Observed fall: No
Year found: 1931
Country: Argentina
Mass:help 79.4 g
Meteoritical Bulletin:  MB 111  (2023)  L5
Recommended:  L5    [explanation]

This is 1 of 8937 approved meteorites (plus 5 unapproved names) classified as L5.   [show all]
Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 29 Jan 2022
Writeup from MB 111:

Malotas (c)        28°56’S, 63°14’W

Santiago del Estero, Argentina

Find: 1931

Classification: Ordinary chondrite (L5)

History: On the morning of June 22, 1931, a meteorite fall was reported in the province of Santiago del Estero, Argentina. Samples of these rocks were given to Professor Juan Olsacher (from Cordoba University) who decided to travel to the place of the fall and collect some pieces. During a visit to the small meteorite collection of the Museo de Cordoba in 2015, Maria Eugenia Varela (MEV) discovered two very different stones named as "Malotas, 1931" in the showcase. One of the samples is the already classified eucrite, Malotas (b). The second piece exhibited is an ordinary chondrite (L5), different to the already classified ordinary chondrite, Malotas (H5). In agreement with the Director of the Museo de Cordoba, the total mass of 79.4 g was given in loan to Icate for detailed studies. From that mass a slide of 10.05 g remains in Icate for further studies. A piece of 1.53 g was sent to PRL (India) for noble gas studies. Also, 0.334 g were sent to the Institute for Geochemistry and Petrology (Switzerland) for CRE age studies.The three samples: Malotas (H5), the eucrite Malotas (b), and the new ordinary chondrite Malotas (c), have different CRE ages. Based on 21Ne-cos, the H5 chondrite has the lowest CRE age of 3 Ma, the L5 chondrite the highest age of 45-52 Ma and the eucrite an intermediate age of 27 Ma. The three samples have very different CRE ages.

Petrography: The stone, is an individual piece weighing 79.4 g and is altered. Few types of chondrules and fragments are visible: BO, RP and POP. The shock features record by crystals are a faint undulatory extinction and no planar fractures, melt pockets or polycrystalline troilite are observed. This indicate a state of shock S2. The moderate degree of oxidation of metal suggest an alteration stage W2.

Geochemistry: Mineral composition: EMP analyses, Olivine Fa24.56 (N=34), Pyroxene Fs21.17Wo1.47 (N=20)

Classification: Ordinary chondrite (L5)

Specimens: Type specimen of 16.25 g and one thin section is on deposit at ICATE, Argentina. The remaining mass is at the MMG-Cordoba.

Data from:
  Table 0
  Line 0:
State/Prov/County:Santiago del Estero
Origin or pseudonym:Malotas
Mass (g):79.4
Shock stage:S2
Weathering grade:W2
Fayalite (mol%):24.6 (N=34)
Ferrosilite (mol%):21.2 (N=20)
Wollastonite (mol%):1.5
Classifier:Julia Roszjar (NHM, Vienna), Marcela E. Saavedra (ICATE) and María E. Varela (ICATE)
Type spec mass (g):16.25
Type spec location:ICATE
Main mass:Museo de Mineralogia y Geologia Dr. Alfred Stelzner, Cordoba, Argentina
Finder:Prof. Juan Olsacher
Comments:Submitted by Maria Eugenia Varela Icate-Conicet
   and collections
NHM: Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom; Website (institutional address; updated 9 Dec 2011)
PRL: Physical Research Laboratory, Navrangpura, Ahmedabad, 380 009, India; Website (institutional address; updated 6 Dec 2017)
ICATE: Instituto de Ciencias Astronomicas de la Tierra y del Espacio Av. España Sur 1512 – San Juan , Argentina; Website (institutional address; updated 31 Oct 2021)
MMG-Cordoba: Museo de Mineralogía y Geología Dr Alfredo Stelzner, Universidad Nacional de Córdoba, Av.Velez Sarsfield 299. Cordoba, Argentina; Website (institutional address; updated 4 Jul 2018)
References: Published in Gattacceca J., McCubbin F. M., Grossman J. N., Schrader D. L., Chabot N. L., D’Orazio M., Goodrich C., Greshake A., Gross J., Joy K. H., Komatsu M. and Miao B. (2023) The Meteoritical Bulletin, No. 111. Meteoritics & Planetary Science 58, 901–904. ?
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     Recommended::   (28° 56'S, 63° 14'W)

     This is 1 of 4 approved meteorites from Santiago del Estero, Argentina (plus 1 unapproved name)
     This is 1 of 81 approved meteorites from Argentina (plus 9 unapproved names) (plus 2 impact craters)
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