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Ubá
Basic information Name: Ubá
     This is an OFFICIAL meteorite name.
Abbreviation: There is no official abbreviation for this meteorite.
Observed fall: No
Year found: 1960
Country: Brazil
Mass:help 84.5 g
Classification
  history:
Recommended:  H5    [explanation]

This is 1 of 10324 approved meteorites (plus 18 unapproved names) classified as H5.   [show all]
Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 17 Jul 2021
Writeuphelp
Writeup from MB 110:

Ubá        ~21°07’S, ~42°57’W

Minas Gerais, Brazil

Find: 1960

Classification: Ordinary chondrite (H5)

History: (M. E. Zucolotto, MN/UFRJ): A 36 g sample of the meteorite was found next to an old card labelled "Ubá" in the MNRJ on a date prior to the fire. The piece was spared from the fire because it was at the IGEO/UFRJ for analysis. On the card was written that the meteorite was found in 1960 with an initial total mass of 84.5 g, located at Mineralogy collection of the Faculty of Philosophy of USP, and this sample was donated by Prof. Ruy Ribeiro Franco and labeled "44-MT." The mass given to the MNRJ was 36 g, but only 24.4 g are remaining.

Physical characteristics: The remaining MNRJ sample measures 36.2 × 25.1 × 14.4 mm and weighs 24.4 g. It is an end-piece of a larger stone with a distinct angular edge and shows dark-brown fusion crust. The cut surface exhibits a slightly brownish-gray interior. Microscopically, the meteorite is quite fresh, with metal phase preserved.

Petrography (M. E. Zucolotto, MN/UFRJ and A. Tosi, IGEO/UFRJ): Under optical microscope, two thin sections were analyzed and showed Ubá as an unbrecciated ordinary chondrite containing a light mm-sized clast set within brownish-gray host with generally readily discernible equilibrated chondrules. Composed predominantly of orthopyroxene, olivine, FeNi metal (kamacite), troilite and interstitial albitic feldspar (<50 µm). Minor Ca-rich pyroxene (pigeonite and augite), taenite, and tetrataenite phases occur. Dark and light regions were observed with the same petrologic texture exhibiting a low shock stage S1 to S2 due to the presence of sharp and undulatory extinction of olivine and presence of Newman lines in kamacite. Troilite is essentially unaltered and most metal is fresh with few oxidized grains (W1).

Geochemistry: (A. Tosi, IGEO/UFRJ) Electron microprobe analysis yields: Host: olivine Fa20.0±0.9 (41); low Ca pyroxene Fs17.1±0.5Wo1.4±0.7 (22); Ca-rich pyroxene Fs12.2±3.6Wo29.1±15.2 (16); plagioclase Ab77.7±3.1An15.9±4.3Or6.67±3.12 (15), Co in Kamacite 4.82±0.02 mg/g (16). Clast: low-Ca pyroxene Fs13.8±1.2Wo1.36±0.7 (10), plagioclase Ab77.0±1.78An17.7±2.9Or5.3±1.57 (10).

Classification: H5 ordinary chondrite. Weathering (W1) and slightly shocked (S1-2)

Specimens: 24.4 g and two thin sections at MNRJ.

Data from:
  MB110
  Table 0
  Line 0:
State/Prov/County:Minas Gerais
Origin or pseudonym:City
Date:1960
Latitude:~21°07'S
Longitude:~42°57'W
Mass (g):84.5
Pieces:2
Class:H5
Shock stage:S1/2
Weathering grade:W1
Fayalite (mol%):20.0±0.9 (n=41)
Ferrosilite (mol%):16.6±0.7 (n=32)
Wollastonite (mol%):1.39±0.7
Classifier:M.E. Zucolotto, MN/UFRJ and A.A.Tosi, IGEO/UFRJ
Type spec mass (g):24.4
Type spec location:MNRJ
Main mass:Mineralogy collection of the Faculty of Philosophy of USP
Finder:unknown
Comments:Submitted by M. E. Zucolotto and A. Tosi; submitted by M. E. Zucolotto and Amanda Tosi
Institutions
   and collections
MNRJ: Museu Nacional, Quinta da Boa Vista, Rio de Janeiro, CEP 20940-040, Brazil (institutional address; updated 26 Dec 2011)
USP: Miriam Della Posta de Azevedo Museu de Geociências - USP Rua do Lago, 562 CEP: 05508-080 Butantã - SP Brazil, Brazil; Website (institutional address; updated 21 Jan 2019)
Catalogs:
References: Published in Meteoritical Bulletin, no. 110, in preparation (2021)
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Photos:
CreditPhotos
Public domain photographs:
Maria Elizabeth Zucolotto      
Geography:

Brazil
Coordinates:
     Recommended::   (21° 7'S, 42° 57'W)

Statistics:
     This is 1 of 22 approved meteorites from Minas Gerais, Brazil (plus 2 unapproved names)
     This is 1 of 82 approved meteorites from Brazil (plus 6 unapproved names) (plus 7 impact craters)
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