Meteoritical Bulletin Announcement 86-1, April 5, 2002

                    THE METEORITICAL BULLETIN

                 Announcement 86-1, April 5, 2002

               Sara Russell, Editor (sara.russell@nhm.ac.uk)

          Jutta Zipfel, Assoc. Ed. for Saharan Meteorites

                  (zipfel@mpch-mainz.mpg.de)

    Jeffrey N. Grossman, Assoc. Ed. for Web (jgrossman@usgs.gov)

                 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: jgrossman@usgs.gov
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.
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                      ANNOUNCEMENTS

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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. Gˆpel, 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 4.1×10-4. 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 MÈmoire 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. Gˆpel, 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, ulvˆspinel, 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; ulvˆspinels 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]