9.96g Ksar Ghilane 022 Achondrite Ungrouped Meteorite Suspected to be from Mercury
*Under classification at CCMS with provisional name Ksar Ghilane 023
Dustin studying the new achondrite with the EMPA (microprobe) at
CU Boulder, working to better understand the exotic sulfides. So far
we have identified; oldhamite, alabandite, daubréelite, and caswellsilverite.
Ksar Ghilane 022 | |||||||||||||||||||||||||||||||||||
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Basic information |
Name: Ksar Ghilane 022 This is an OFFICIAL meteorite name. Abbreviation: KG 022 Observed fall: No Year found: 2023 Country: Tunisia Mass: 50 kg |
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Classification history: |
This is 1 of 154 approved meteorites classified as Achondrite-ung. |
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Comments: | Approved 20 May 2024 | ||||||||||||||||||||||||||||||||||
Writeup |
Writeup from MB 113:
Ksar Ghilane 022 (KG 022) 32.559°N, 9.508°E Tatawin, Tunisia Purchased: 2023 Classification: Ungrouped achondrite History: Found in Tunisia in 2023. Purchased by Adam Aaronson in February and November 2023 from a Libyan dealer. Portions of the material were subsequently provided to Craig Zlimen at the Tucson Gem and Mineral Show in February 2024, and in turn acquired by Robert Ward, Brian Caress and Ben Hoefnagels. Physical characteristics: A single large stone (25 kg) and many smaller pieces found with it. Most of the stones lack fusion crust and have mottled, dark and light gray granular exteriors. However, several pieces are partly coated by black fusion crust. The interiors of the stones have the appearance of equigranular aggregates of light gray and whitish grains. Petrography: (A. Irving, UWS, and P. Carpenter, WUSL) The specimen is composed predominantly (>90 vol.%) of almost end-member augite (mostly as equant grains, mean grainsize ~1.5 mm) accompanied by minor enstatite and accessory Cr-troilite, daubreelite, alabandite and an Mn-Fe oxide phase. Enstatite occurs as small irregular inclusions or sparse fine lamellae within augite grains, and different macroscopic colors of the augite grains apparently reflect differing concentrations of sulfide inclusions. Some secondary calcite veins are present throughout. Geochemistry: Augite (Fs0.0-0.1Wo39.4-42.3, N = 3), enstatite (Fs0.1±0.0Wo0.9-3.6, N = 3). Oxygen isotopes (K. Ziegler, UNM): analyses of acid-washed subsamples by laser fluorination gave, respectively, δ17O 3.018, 2.926; δ18O 5.781, 5.559; Δ17O -0.034, -0.009 per mil (all data linearized, TFL slope = 0.528). Classification: Achondrite (ungrouped, Mg-rich clinopyroxenite). This meteorite is texturally and mineralogically very similar to ungrouped augite-rich achondrite NWA 15915. but does not exhibit the same degree of irrational exsolution of enstatite from the dominant constituent augite. Terrestrial pairing is further excluded by the different physical appearance of these two meteorites, different degree of weathering, and the fact that their purported find sites are hundreds of kilometers apart. Both of these meteorites may have some affinities to aubrites, but differ in being composed predominantly of almost Fe-free augite rather than enstatite. Specimens: 41.3 g including one polished thin section at UWB; 677 g with Mr. R. Ward; 770 g with Mr. B. Caress; 674 g with Mr. B. Hoefnagels; 800 g with Mr. D. Dickens; remainder including the 25 kg main mass with Aaronson. |
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Data from: MB113 Table 0 Line 0: |
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Ksar Ghilane 023 | |||||
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Basic information | Name: Ksar Ghilane 023 This is a PROVISIONAL name. It cannot be used in publications. Abbreviation: KG 023 Observed fall: No Year found: 2024 Country: Tunisia Mass: 10 kg |
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Classification history: |
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Catalogs: |
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Provisional info: |
Name: Ksar Ghilane 023 Fieldname: MURC1 Origin/pseudonym: Tunisia Purchased: Libya Purchase or find date: Febuary, 2024 Lat/long: 32°33'31.4"N , 09°30'27.2"E Mass: 10 Kg Pieces: many Specimens: 20g TCU Description: An ungrouped magnesian clinopyroxenite achondrite with approximately >90% subcalcic diopside Fs0-0.1, <10% orthopyroxene Fs0-0.1, and >1% aubrite-like sulfides, oxygen plots to TFL, no olivine or plagioclase was found. Info: This meteorite may pair to Northwest Africa 15915 Name assigned to: Dustin Dickens Date assigned: 2024-05-03 Assigned by: Dustin Dickens |
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References: |
Never published in the Meteoritical Bulletin
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Geography: |
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