CM
Name
*click on the Name for more information
Structure Class
Carbonaceous chondrites
Chemical Class
CM2
Country
Year found
2022
Mass
800 g
[Museum Collection]
(1) 0.26g (2) 0.21g (3) 0.18g (4) 0.17g
(5) 0.17g




History: Many identically appearing pieces were found on December 5, 8 and 13, 2021, along an approximately 10 km traverse. Purchased from Mouha Bouyat on February 22, 2022. Physical characteristics: Dark fusion-crusted exterior, broken surface reveals numerous small chondrules set in a dark gray matrix that makes up over 50% of this meteorite. Small CAIs are visible. Petrography: (A. Ross and C. Agee, UNM) Chondrules and Small CAIs set in a fine-grained matrix (>50 vol%) . Most chondrules are porphyritic type I with predominantly forsteritic olivines. Matrix olivines are mostly fragmental and ferroan. Apparent mean chondrule diameter approximately 300 μm. Aluminous diopside, troilite, Fe-Ni sulfide, and low-Ni iron were detected. Geochemistry: (A. Ross and C. Agee, UNM) Type I chondrule olivine Fa0.9±0.3, Cr2O3=0.37±0.20 (wt%) n=4; ferroan matrix olivine Fa38.3±6.9, Fe/Mn=97±22, Cr2O3=0.29±0.14 (wt%) n=4; low-Ca pyroxene Fs3.0±2.3Wo2.4±2.1, n=4; matrix (20 ?m defocused microprobe beam) analytical totals of 77.6±2.4 wt% and FeO=35.5±3.4 wt%, n=7. Classification: Carbonaceous chondrite (CM2). The low analytical totals in the matrix indicate the presence of hydrous phases. Specimens: 20 g on deposit at UNM, Mouha Bouyat and Matthew Stream hold the main mass.
Name
*click on the Name for more information
Structure Class
Carbonaceous chondrites
Chemical Class
CM2
Country
Year found
2019
Mass
27 kg
[Museum Collection]
(1) 2.37g (2) 143.2g




History: (G.J. Soto; P. Madrigal, O. Lücke, Escuela Centroamericana de Geología, Universidad de Costa Rica; M. Farmer, Arizona) At 21:07 local time on 23 April 2019, a meteorite fall was reported in Aguas Zarcas, San Carlos county, Alajuela province, Costa Rica. The fireball traveled WNW to ESE and was caught on cameras of the National Seismological Network (RSN) at the summit of Poás and Turrialba volcanoes, and from the Volcanological and Seismological Observatory of Costa Rica (OVSICORI). Sightings were reported from Quepos (Central Pacific) in the south and north to La Palmera in San Carlos. The first piece recovered, 1152 g, crashed through a house at 10°23’29.03"N, 84°20’28.58"W. A dog house was hit by a 280 g piece at 10°24’9.35"N 84°21’51.26"W. The BRAMON (Brazilian Meteors Observation Network), UNESP (São Paulo State University) and USP (University of São Paulo) teams determined the atmospheric trajectory of the bolide from four security videos and dashcam cameras. The bolide had an entry angle of 73° relative to the ground, traveling 20.7 km in the 4-s analyzed interval, with an atmospheric velocity of 14 km/s. Analysis shows a projected elliptical strewn-field with major axis length of 6.3 and minor axis of 3.3 km. Hundreds of stones were recovered within the projected strewn-field. The bolide orbit was determined, with the follow preliminary elements: semi-major axis 2.7 AU, eccentricity 0.63, inclination 3.09°, pericenter longitude of 185.3° and ascending node 33.4°. Current total recovered mass is around 27 kg, of which ~11 kg was collected before rain fell over the fall site. Physical characteristics: (L. Garvie, ASU) Hundreds of fusion-crusted stones ranging from 0.1 to 1868 g. Stones under ~50 g are typically angular to blocky and lack regmaglypts. Also found were several plate-like, oriented stones. For example, one oriented plate is 13 cm wide and 1 cm thick. Many stones are oriented with a domed leading edge and well-developed roll-over lip along the rim of the trailing edge. Larger stones, especially those near 1 kg, show broad regmaglypts, some well developed. The fusion crust on several of the trailing edge surfaces is iridescent. Pre-rain material crushed in a few ml of water emits a powerful "Murchison-like" odor, though with a more prominent compost-like scent. Petrography: (L. Garvie, ASU) The interior of the stones is uniformly dark gray and studded with small light-colored speckles. Stones are brecciated and dominated by two lithologies: chondrule poor, constituting ~80 areal% of the broken surfaces examined (~2 kg of material), and chondrule rich. Chondrules constitute ~10 areal% of the chondrule-poor lithology and ~40 areal% in the chondrule-rich lithology. Some broken surfaces show clasts of the chondrule-rich lithology in the chondrule-poor type. Clasts with lower chondrule to matrix ratio also present; for example, one 3 g half stone shows
Name
*click on the Name for more information
Structure Class
Carbonaceous chondrites
Chemical Class
CM2
Country
Year found
2013
Mass
6 kg
[Museum Collection]
(1) 9.215g (2) 9.473g (3) 11.474g (4) 2.7g




• 分類 :炭素質コンドライト • 発見隕石 :2013年 • 落下国 :モロッコ西サハラ • 発見総重量 :6 kg • 同分類の隕石数:658個 • 原始太陽系円盤中の塵が集合した小天体の破片。 集積後,温泉水による化学反応により塵が粘土に 変化しているが,反応していないものも残っている。 • マーチソン隕石に比べて茶色いのは,砂漠での風化による錆のせいである。 【 監修 北海道大学 圦本尚義 】 • carbonaceous chondrite CM2 • Found 2013 • Morocco/Western Sahara • Found 6 kg • one of 658 meteorites in this classification • This is a fragment of a small body that was formed by the accretion of dusts in the proto-solar disk. After accretion, the dusts has been altered to clay minerals by chemical reaction with hot spring water, but some dusts remained intact. • The brownish color of this meteorite compared to the Murchison meteorite is due to rust from weathering in the desert. 【Supervised by Prof. Hisayoshi Yurimoto, Hokkaido University】
*click on the Name for more information
Name
Structure Class
Carbonaceous chondrites
Chemical Class
CM2
Country
Year found
1969
Mass
100 kg
[Museum Collection]
(1) 20.52g (2) 14.79g (3) 13.77g (4) 12.00g
(5) 5.30g (6) 4.95g




• 分類 :炭素質コンドライト • 落下隕石:1969年 • 落下国 :オーストラリア • 発見総重量 :100 kg • 同分類の隕石数:658個 • 原始太陽系円盤中の塵が集合した小天体の破片。集積後,温泉水による化学反応により塵が粘土に変化しているが,反応していないものも残っている。 • アミノ酸等の有機物を豊富に含む。 【 監修 北海道大学 圦本尚義 】 • carbonaceous chondrite CM2 • Fall 1969 • Australia • Found 100 kg • one of 658 meteorites in this classification • This is a fragment of a small body that was formed by the accretion of dusts in the proto-solar disk. After accretion, the dusts has been altered to clay minerals by chemical reaction with hot spring water, but some dusts remained intact. • Rich in organic matter such as amino acids. 【Supervised by Prof. Hisayoshi Yurimoto, Hokkaido University】

