Below are excerpts from a Meteoritical Bulletin announcement sent out today on seven recent Mars meteorites finds. Of these Mars meteorites, SAU 060 and SAU 090 are new. Since these two Mars meteorite were found near the other four SAU Mars meteorites and are also basaltic shergottites, they are assumed to be paired with this group. Taking into account pairings, the number of Mars meteorites remains at 24.
THE METEORITICAL BULLETIN Announcement 86-1, April 5, 2002 Sara Russell, Editor (email@example.com) Jutta Zipfel, Assoc. Ed. for Saharan Meteorites (firstname.lastname@example.org) Jeffrey N. Grossman, Assoc. Ed. for Web (email@example.com) Monica M. Grady, Co-Editor Announcements of new meteorites to be published in Meteoritical Bulletin, No. 86, 2002 July. Here, you will find the complete text of announcements of Martian meteorites described in the past year. Marian meteorites described below: Dhofar 378 Basaltic shergottite (Oman) Grove Mountains 99027 Lherzolitic shergottite (Antarctica) Northwest Africa 856 Basaltic shergottite (Africa*) Northwest Africa 1068 Basaltic shergottite (Africa*) Northwest Africa 1110 Basaltic shergottite (Africa*) Sayh al Uhaymir 060 Basaltic shergottite (Oman) Sayh al Uhaymir 090 Basaltic shergottite (Oman) *) Morocco or surrounding countries. The preliminary text of the 2002 Meteoritical Bulletin, including the above meteorites and those in E-mail Announcements 86-2 and 86-3, may by viewed at: http://www.uark.edu/campus-resources/metsoc/metbull/mb86.pdf ***PLEASE REPORT ERRORS BY 14 APRIL 2002 TO: firstname.lastname@example.org All information in this e-mail and on the above-cited Meteoritical Bulletin webpage is subject to revision until final publication in the summer of 2002. =========================================================== ANNOUNCEMENTS =========================================================== Dhofar 378 18°9.5' N, 54°6.8' E Oman Found 2000 June 17 Martian meteorite (basaltic shergottite) A single stone of 15 g, covered with fresh black fusion crust, was recovered by an anonymous finder within the province of other Dhofar meteorites. Classification and description: (Y. Ikeda and M. Kimura, Dept. of Materials and Biological Sciences Ibaraki; H. Takeda, Chiba): It has a doleritic or microgabbroic texture, and the grain sizes of the main minerals (pyroxenes and plagioclase glass) are about 1 mm across. It consists mainly of ferroan pyroxenes (augite and pigeonite), and plagioclase glass with quenched plagioclase rims. Minor minerals are hedenbergite, pyroxferroite, fayalite, silica, Ti-rich magnetite, ilmenite, sulfide, phosphate, and rhyolitic glass. The Fe/(Mg+Fe) ratios of pyroxenes (augite and pigeonite) range from 0.40 to more than 0.90, those of hedenbergite from 0.97 to 0.99, and olivine from 0.90 to 0.98. The original plagioclase grains were transformed to plagioclase glass (An35 to An55) by an intense impact shock, then quenched plagioclase of the same composition a few tens of mm up to one hundred mm in width at the boundaries between the plagioclase glass and other minerals. Oxygen isotopic composition (T.K. Mayeda and R.N. Clayton, UChi): d18O == +4.46 permil, d17O == +2.52 permil. This meteorite was recovered from an area near the Dhofar 019 basaltic shergottite, but the two meteorites are probably not paired. Dhofar 019 is doleritic and contains olivine grains with Fe/(Mg+Fe) ratios of 0.4-0.75, whilst these seem to be absent from Dhofar 378. Pyroxenes in Dhofar 019 are more magnesian than in Dhofar 378. Specimens: type specimens 0.445 g & 0.054 g, Ibaraki; 2.74 g MPI; main mass is with the anonymous finder. Grove Mountains (GRV) 99027 73°06'01" S, 75°14'13" E Antarctica Found 2000 February 8 Martian meteorite (lherzolitic shergottite) This meteorite weighs 9.97 g, and most of the surface is covered by fusion crust. Classification and Mineralogy (Lin and B. Miao, GIG; H. Wang & C. Lin, NU): It is composed mainly of coarse-grained orthopyroxene, olivine, clinopyroxene and plagioclase, with minor opaque minerals. There are two textures. In the larger part of the sections, olivine occurs as rounded euhedral grains, poikilitically enclosed in a megacryst of orthopyroxene; in the other side of the sections, it shows a cumulate texture, consisting of euhedral orthopyroxene, clinopyroxene, olivine and interstitial plagioclase. Chromite, the most common opaque phase, is euhedral and enclosed in pyroxenes. The mineral assemblage and textures are similar to the Allan Hills (ALHA) 77005 lherzolite. The FeO/MnO (wt%) ratio of orthopyroxene is 34+/-5. Compositions of orthopyroxene (En66-78Fs20- 26Wo2-8), clinopyroxene (En48-52Fs13-15Wo34-39), olivine (Fa22-30) and plagioclase (An49-55Ab44-50Or<1) overlap with the ranges in ALHA77005. Fracturing and undulose extinction in silicates are strong. Plagioclase is commonly deformed, and partially turns into maskelynite along the boundaries of grains. The shock stage is S4; weathering grade, W1. The meteorite is curated at PRIC. Northwest Africa 856 unknown location Found 2001 March Martian meteorite (basaltic shergottite) A single stone of 320 g was found in Morocco in March 2001. The exact location of find is unknown and the meteorite was referred to under the pseudonym "Djel Ibone". The meteorite has a fine-grained basaltic texture consisting mainly of pyroxene (70 vol%) and maskelynite (23 vol%). Accessory minerals include merrillite, apatite, pyrrhotite, chromite, Fe-Ti oxides, silica (stishovite) and baddeleyite. Melt pockets with phenocrysts and submicron-sized needles of stishovite are present. Pyroxenes are highly fractured. Calcite veins formed by terrestrial weathering cross-cut the specimens. Classification and mineralogy (A. Jambon, UPVI, V. Sautter, MNHNP, Ph. Gillet, ENSL): pyroxenes are pigeonite, En48Fs39Wo13, and augite, En36Fs32Wo32; maskelynite composition is An41-47Ab57-51Or2. Geochemistry (J.-A. Barrat, UAng and Ch. Göpel, IPGP): bulk composition in wt% is 0.81 TiO2, 6.83 Al2O3, 17.8 FeO*, 0.49 MnO, 9.51 MgO, 10.2 CaO, 1.28 Na2O, 0.13 K2O. Trace elements 77 ppm Ni and a REE pattern similar to that of Shergotty and Zagami. Key element weight-ratios are FeO*/MnO ~30, Na/Al ~0.40, K/La of 500 and Ga/Al of 4.1x10-4. Abundances of Ba and Sr and the Th/U ratio indicate that terrestrial weathering is minor. Specimens: type specimen, 16 g, ENSL; main mass, Fectay. Northwest Africa 1068 Morocco Found 2001 April Martian meteorite (basaltic shergottite) In 2001 April, meteorite hunters of the local team of "La Mémoire de la Terre" recovered 23 stones (one large mass, 522 g, and 22 small fragments, <20 g; total known mass, 576.77 g) in the Moroccan Sahara. Rocks are greenish-brown and partially coated by desert varnish; no fusion crust; cracks filled with terrestrial calcium carbonate. Thin shock veins and small melt pockets are abundant. Classification, mineralogy and bulk chemistry (J.-A. Barrat, UAng, A. Jambon, UPVI, M. Bohn, I-CB, Ph. Gillet, ENSL, V. Sautter, MNHNP, Ch. Göpel, IPGP, M. Lesourd, SCIAM): consists of olivine (50 um to 2 mm) in a fine- grained groundmass (average grain size ~100 um) of euhedral to subhedral pyroxene crystals and interstitial maskelynite; minor phases are chromite, Ti-chromite, ilmenite, ulvöspinel, sulfides, merrillite, apatite, and a K-rich mesostasis; impact melt pockets (up to 1.5 mm long) contain pyrrhotite spherules. Modal abundances of impact melt pockets and calcite free areas: 52 vol% pyroxenes, 22 % maskelynite, 21 % olivine, 2 % phosphates, 2 % opaque oxides and sulfides, and 1 % K-rich mesostasis. Mineralogy: olivine (Fa28 to Fa58); pyroxenes: pigeonite (En57Wo5Fs28 to En40Wo13Fs47; fe# (100 Fe/(Fe+Mg) == 29-54 at. %) and augite (En55Wo21Fs24 to En35Wo28Fs36; fe# == 29-51 at. %) are present as separate crystals in roughly equal volume proportions; maskelynite is zoned (An53Ab45Or2 to An49Ab48Or3) but is locally An-poor (An35Ab57Or8); FeO-rich merrillite (FeO 1.3 and 2.8 wt.%); apatites, Cl 0.5-2.5 wt% and F 1.1-6.4 wt%; chromite have Ti-rich rims; ulvöspinels contain fine ilmenite lamellae (< 1 um thick). An interstitial K-rich component, probably a shock- produced glass of alkali feldspar and silica, is generally associated with Fe-Ti oxides. Bulk chemistry: Al-poor ferroan basaltic rock, rich in MgO with major element abundances similar to those reported for EETA79001 lithology A. Key element weight ratios are Fe/Mn == 45, Al/Ti == 6.6, Na/Ti == 1.83, and Na/Al == 0.28. REE pattern similar to Shergotty, Zagami, and Los Angeles. Specimens: type specimen, 20 g and 2 polished sections, ENSL; main mass, Fectay. Northwest Africa 1110 Morocco Purchased 2001 November Martian meteorite (basaltic shergottite) G. and A. Hupe (Hupe) received a small sample of this meteorite in 2001 September and bought the rest from a dealer in Erfoud, Morocco in 2001November . The weight of the total material purchased is 118 g. The place of recovery is believed to be in Morocco. Classification and mineralogy (A. Irving and S. Kuehner, UWS): consists of olivine phenocrysts in a fine-grained groundmass of complexly-zoned pigeonite and homogenous maskelynite, Ab46Or2, with minor ilmenite, Ti-magnetite and pyrrhotite. Euhedral to subhedral olivine has Mg-rich cores (Fa28, FeO/MnO == 50) and narrow Fe-rich rims (Fa51, FeO/MnO == 53) and contain inclusions of chromite and glass; augite (Fs33Wo21) occurs as rare inclusions in olivine; pigeonite is zoned, Fs28Wo9 to Fs40Wo15 and FeO/MnO == 30; presence of rare chlorapatite in mesostasis. Secondary features include minor barite, commonly associated with chromite inclusions in olivine, calcite, in a cross-cutting glass veinlet, and narrow zones of K-Al- bearing glass or clay minerals along grain boundaries between pyoxene and maskelynite. Mineral composition indicates that this rock is possibly paired with NWA 1068. Specimens: type specimen, 20 g and several thin sections, UWS; main mass, Hupe. Sayh al Uhaymir 060 20°58.8' N, 57°19.1' E Oman Found 2001 June 27 Martian meteorite (basaltic shergottite) A small 42.28 g partially crusted grey-greenish stone was found near to the area of previous finds of Sayh al Uhaymir 005/008/051/094. All five meteorites seem to be paired. Mineralogy and classification (S. Afanasiev, Vernad): has a porphyritic texture with large olivine phenocrysts (Fo63.1-70.8) set in a groundmass consisting of maskelynite (An61.4-68.3 Or0.5-1.6) and pigeonite (En60-69.6 Wo7.1- 8.6), augite (En47 Wo35) is rare; shock stage, S5; slight weathering. Analyzed by Dr. N. N. Kononkova (Vernad). Specimens: type specimen, 9.5 g, Vernad; main mass with anonymous finder Sayh al Uhaymir 090 21°00.0' N, 57°19.2' E [This 94.84 g stone is probably paired with Sayh al Uhaymir 060, as well as 005/008/051/094]
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