The polymict carbonaceous breccia Aguas Zarcas: A potential analog to samples being returned by the OSIRIS‐REx and Hayabusa2 missions
Bischoff, Addi
Zolensky, Michael E.
Pack, Andreas
Patzek, Markus
Hanna, Romy D.
Fries, Marc D.
Harries, Dennis
Kebukawa, Yoko
Le, Loan
Ito, Motoo
Rahman, Zia
DOI: https://doi.org/10.1111/maps.13620
Persistent URL: http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8551
Zolensky, Michael E.; 2Astromaterials Research and Exploration Science NASA Johnson Space Center Houston Texas 77058 USA
Pack, Andreas; 4Universität Göttingen Geowissenschaftliches Zentrum Goldschmidtstr. 1 Göttingen D‐37077 Germany
Patzek, Markus; 1Institut für Planetologie University of Münster Wilhelm‐Klemm Str. 10 Münster D‐48149 Germany
Hanna, Romy D.; 5Jackson School of Geosciences University of Texas Austin Texas 78712 USA
Fries, Marc D.; 2Astromaterials Research and Exploration Science NASA Johnson Space Center Houston Texas 77058 USA
Harries, Dennis; 6Institut für Geowissenschaften Friedrich‐Schiller‐Universität Jena Carl‐Zeiss‐Promenade 10 Jena 07745 Germany
Kebukawa, Yoko; 7Faculty of Engineering Division of Materials Science and Chemical Engineering Yokohama National University 79‐1 Tokiwadai, Hodogaya Ward Yokohama Kanagawa 240‐8501 Japan
Le, Loan; 8Jacobs JETS Johnson Space Center 2101 NASA Parkway Houston Texas 77058 USA
Ito, Motoo; 9Japan Agency for Marine‐Earth Science Technology (JAMSTEC) Kochi Institute for Core Sample Research 200 Monobe Otsu Nankoku City Kochi 783‐8502 Japan
Rahman, Zia; 8Jacobs JETS Johnson Space Center 2101 NASA Parkway Houston Texas 77058 USA
Abstract
On April 23, 2019, a meteorite fall occurred in Aguas Zarcas, Costa Rica. According to the Meteoritical Bulletin, Aguas Zarcas is a brecciated CM2 chondrite dominated by two lithologies. Our X‐ray computed tomography (XCT) results show many different lithologies. In this paper, we describe the petrographic and mineralogical investigation of five different lithologies of the Aguas Zarcas meteorite. The bulk oxygen isotope compositions of some lithologies were also measured. The Aguas Zarcas meteorite is a breccia at all scales. From two small fragments, we have noted five main lithologies, including (1) Met‐1: a metal‐rich lithology; (2) Met‐2: a second metal‐rich lithology which is distinct from Met‐1; (3) a brecciated CM lithology with clasts of different petrologic subtypes; (4) a C1/2 lithology; and (5) a C1 lithology. The Met‐1 lithology is a new and unique carbonaceous chondrite which bears similarities to CR and CM chondrite groups, but is distinct from both based on oxygen isotope data. Met‐2 also represents a new type of carbonaceous chondrite, but it is more similar to the CM chondrite group, albeit with a very high abundance of metal. We have noted some similarities between the Met‐1 and Met‐2 lithologies and will explore possible genetic relationships. We have also identified a brecciated CM lithology with two primary components: a chondrule‐poor lithology and a chondrule‐rich lithology showing different petrologic subtypes. The other two lithologies, C1 and C1/2, are very altered and possibly related to the CM chondrite group. In this article, we describe all the lithologies in detail and attempt a classification of each in order to understand the origin and the history of formation of the Aguas Zarcas parent body.