| Sample No.: | ALH94007 |
| Location: | Allan Hills |
| Dimensions (cm): | 1.5 x 1.0 x 0.75 |
| Weight (g): | 1.24 |
| Meteorite Type: | L3 Chondrite (estimated L3.4) |
Macroscopic Description: Kathleen McBride
The exterior surface of this meteorite is weathered brown with
thin patches of fusion crust. Fractures penetrate the surface.
The interior is brown with heavy oxidation and some metal visible.
Thin Section (,2) Description: Brian Mason
The section shows numerous chondrules (up to 1.8 mm across), chondrule fragments, and mineral grains in a black matrix that contains a small amount of nickel-iron and troilite. The meteorite is considerably weathered, with limonitic staining and patches of brown limonite throughout the section. Microprobe analyses show olivine and pyroxene of variable composition: olivine, Fa7-38, mean Fa17: pyroxene, Fa1-21. The meteorite is classified as an L3 chondrite (estimated L3.4).
| Sample No.: | QUE94613 |
| Location: | Queen Alexandra Range |
| Dimensions (cm): | 2.0 x 1.5 x 1.0 |
| Weight (g): | 5.1 |
| Meteorite Type: | Ureilite |
Macroscopic Description: Kathleen McBride
Forty percent of the exterior of this meteorite is covered with
dark brown to black fusion crust. Areas without fusion crust are
rusty brown in color. The interior is dull brown to black with
some metal grains and some weathered mineral grains visible.
Thin Section (,2) Description: Brian Mason
The section shows anhedral grains of olivine and a little pyroxene (grains up to 2.4 mm across) in a black matrix. The matrix contains veinlets of brown limonite, presumably from the weathering of metal and sulfide. Microprobe analyses show olivine of nearly uniform composition, Fa22-24, with notably high CaO (0.4%); pyroxene composition is Wo10Fs19. The meteorite is a ureilite; it appears to be relatively unshocked compared to most ureilites. It is probably paired with QUE93336 and 93341.
| Sample No.: | QUE94614 |
| Location: | Queen Alexandra Range |
| Dimensions (cm): | 1.5 x 1.5 x 0.5 |
| Weight (g): | 2.5 |
| Meteorite Type: | Mesosiderite |
Macroscopic Description: Kathleen McBride
Thin, black shiny patches of fusion crust are present on this
meteorite's exterior surface. Areas without fusion crust are weathered
brown. The interior is brown and fine grained. A few mineral grains
are visible and oxidation is present.
Thin Section (,2) Description: Brian Mason
The section shows plagioclase and pyroxene clasts, up to 1.5 mm across, in an opaque matrix of nickel-iron and troilite (the nickel-iron extensively weathered to brown limonite). Most of the pyroxene is hypersthene, with compositions clustered around Wo2Fs24, but a few calcium-rich grains were analyzed, up to Wo34Fs32. Plagioclase compositions are An91-96. Trace amounts of an SiO2 polymorph, probably tridymite, are present. The meteorite is a mesosiderite; it is very similar to QUE86900, with which it is probably paired.
| Sample No: | QUE94616 |
| Location: | Queen Alexandra Range |
| Dimensions (cm): | 3.0 x 2.5 x 1.5 |
| Weight (g): | 13.6 |
| Meteorite Type: | Howardite |
Macroscopic Description: Kathleen McBride
The exterior surface of this achondrite is dark gray in color
with a small patch of black fusion crust. The exterior has a pebbly
texture. The interior reveals a dirty gray matrix with abundant
mm-sized white, black and gray inclusions. Minor oxidation is
visible.
Thin Section (,2) Description: Brian Mason
The section shows a microbreccia of pyroxene and plagioclase clasts in a comminuted groundmass of these minerals; the groundmass contains a few small grains of opaques. The pyroxene is orthopyroxene with a lesser amount of pigeonite; orthopyroxene clasts are up to 1.5 mm across, whereas pigeonite clasts are smaller. Microprobe analyses show othropyroxene of essentially uniform composition, Wo3Fs24, and a wide range of pigeonite compositions, Wo5-30, Fs17-58. Plagioclase composition is An74-92. Two grains of olivine, Fa59, Fa62, were analyzed. The meteorite is a howardite.
| Sample No.: | QUE94639 |
| Location: | Queen Alexandra Range |
| Dimensions (cm): | 1.1 x 1.0 x 0.2 |
| Weight (g): | 0.6 |
| Meteorite Type: | Mesosiderite |
Macroscopic Description: Carol Schwarz
The exterior surface of this small flat fragment is dark brown
with a few mm-sized yellow and green mineral grains visible. Some
evaporite is also present. The interior is dark brown, mostly
metal, with yellow and brown crystals scattered throughout.
Thin Section (,2) Description: Brian Mason
This section shows plagioclase and pyroxene clasts, up to 1.2 mm across, in an opaque matrix of nickel-iron and troilite (the nickel-iron extensively weathered to limonite). Most of the pyroxene is hypersthene, with composition near Wo3Fs28, but one grain of augite, Wo40Fs27, was analyzed. Plagioclase composition is An91-96. One grain of tridymite was analyzed. The meteorite is a mesosiderite, and can be confidently paired with QUE86900.
| Sample No.: | QUE94688 |
| Location: | Queen Alexandra Range |
| Dimensions (cm): | 2.2 x 1.8 x 1.1 |
| Weight (g): | 10.55 |
| Meteorite Type: | CV3 Chondrite |
Macroscopic Description: Cecilia E. Satterwhite
Dull black fusion crust covers sixty percent of the exterior of
this carbonaceous chondrite. The interior reveals a black fine
grained matrix with some weathered inclusions. White mm-sized
inclusions are abundant on the exterior and interior surfaces.
Thin Section (,2) Description: Brian Mason
The section shows numerous chondrules (up to 1.8 mm across), irregular aggregates, and mineral grains in a black matrix. A small amount of nickel-iron and troilite is present at the rims and within the chondrules. Microprobe analyses show that most of the olivine in the chondrules is close to Mg2SiO4 in composition, but olivine grains in the matrix are more iron-rich, ranging up to Fa33; pyroxene is rare, a single grain measured was Fs1. The matrix appears to consist largely of iron-rich olivine, about Fa45. The meteorite is classified as a C3 chondrite of the Vigarano subtype; it is very similar to QUE93429, and the possibility of pairing should be considered.
| Sample No.: | QUE94734 |
| Location: | Queen Alexandra Range |
| Dimensions (cm): | 3.0 x 2.1 x 2.0 |
| Weight (g): | 11.17 |
| Meteorite Type: | C2 Chondrite |
Macroscopic Description: Cecilia E. Satterwhite
Fifty percent of the exterior of this carbonaceous chondrite is
covered with fractured black fusion crust. Flow lines are present
on the fusion crust on some surfaces. Areas without fusion crust
are dull and brownish gray in color. The interior reveals a black
fine grained matrix with mm-sized gray inclusions.
Thin Section (,2) Description: Brian Mason
The section shows sparse chondrules, up to 0.9 mm across, some irregular aggregates, and numerous small silicate grains in a dark brown to black matrix. The silicate grains are almost entirely olivine near Mg2SiO4 in composition, with a few more iron-rich grains. A little pyroxene near MgSiO3 in composition is present. The matrix appears to consist largely of iron-rich serpentine. The meteorite is a C2 chondrite.
| Sample No.: | GRO95511 |
| Location: | Grosvenor Mountains |
| Dimensions (cm): | 3.6 x 3.0 x 1.5 |
| Weight (g): | 64.4 |
| Meteorite Type: | Iron - Coarse Octahedrite |
Macroscopic Description: Roy S. Clarke, Jr.
This oval-shaped button was oriented during atmospheric passage,
resulting in a domed anterior surface with a flat posterior. A
thin film of reddish brown to black secondary oxides covers the
specimen. There is a suggestion of an accumulation of material
at the rim where the two surface types join, but fusion crust
is not apparent. The internal Widmanstatten pattern stands out
in relief on the anterior surface, while the posterior surface
is matted terrestrial oxides.
Polished Section Description: Roy S. Clarke, Jr.
A median slice perpendicular to both the long axis of the oval and to the flat posterior surface was removed, producing butts of 27.5 g and 20.7g, and a 3.1 mm slice of 7.7 g from which a metallographic section was prepared. Fusion crust is absent on the anterior surface, but an accumulation of columnar fusion crust is present at both ends of the posterior surface. They are ~1mm thick near the rim where the surfaces join, and taper to nothing in ~9mm. Heat alteration as indicated by 2 structure affects all but the most interior parts of the section. The plane of section is parallel to the 100 direction of the parent taenite, resulting in a Widmanstatten pattern of kamacite bands in two orthogonal directions with widths of approximately 1.5 mm. The structure, although heat-altered, is regular and otherwise undistorted. It contains several of the more common taenite-plessite structures. Neumann bands are present in the 2-free kamacite. Rhabdites are present within kamacite, and grain-boundary schreibersites and taenite-border schreibersites are present. Troilite was not observed but is probably present. Both GRO95511 and GRO95522 are similar in appearance and weathering history. Their Widmanstatten patterns are revealed on different planes, and they have different exposures to preterrestrial distortion and heating. This makes it difficult to suggest if they represent two separate falls or are individuals from a shower. Definitive classification and pairing information awaits trace element analysis.
| Sample No.: | GRO95522 |
| Location: | Grosvenor Mountains |
| Dimensions (cm): | 9.4 x 8.0 x 3.0 |
| Weight (g): | 962.3 |
| Meteorite Type: | Iron - Medium to Coarse Octahedrite |
Macroscopic Description: Roy S. Clarke, Jr.
This specimen is an irregular-shaped oval with a smooth anterior
surface and a comparatively rough and irregular posterior. The
gentle rounding of the anterior surface suggests oriented flight
during atmospheric passage. A thin film of reddish brown to black
secondary oxides covers the specimen. The internal Widmanstatten
pattern stands out in slight relief over much of the anterior
surface, while the posterior surface is irregular, and contains
depressions apparently due to terrestrial corrosion.
Polished Section Description: Roy S. Clarke, Jr.
A median slice perpendicular to both the long axis of the oval and an approximated plane of the posterior surface was removed, producing butts of 698 g and 170 g, and a slice of 49 g. A 2.5 cm2 piece was taken for a metallographic section. Fusion crust is absent except for a small accumulation of melt crust on the posterior surface at the rim with the anterior surface. Its maximum width is ~0.3 mm near the union of the surfaces, and it tapers to nothing by 5 mm into the interior. The slice is bordered with a heat-altered zone of ~3 mm on the anterior surface, and of generally narrower and more variable widths on the posterior surface. The plane of cut revealed three directions of the Widmanstatten pattern unequally displayed. Kamacite band widths are ~ 1.3 mm. The kamacite contains Neumann bands, many of which show mild preterrestrial distortion, as do the kamacite bands themselves. Rhabdites are not prominent, but grain-boundary schreibersite and some taenite-border schreibersite are present. Several morphologies of taenite-plessite are present. Close to the anterior surface within an area of fairly high structural distortion is a shattered, euhedral chromite (1.7 x 0.5 mm) surrounded by ~0.4 mm of troilite along the long dimension and ~0.8 at the ends. The exterior of the troilite is bordered over part of its outer edge with schreibersite, and where it is in contact with kamacite, it appears to have been partially melted. Both GRO95511 and GRO95522 are similar in appearance and weathering history. Their Widmanstatten patterns are revealed on different planes, and they have different exposures to preterrestrial distortion and heating. This makes it difficult to suggest if they represent two separate falls or are individuals from a shower. Definitive classification and pairing information awaits trace element analysis.
| Sample No.: | GRO95533 |
| Location | Grosvenor Mountains |
| Dimensions (cm): | 13.2 x 7.1 x 5.8 |
| Weight (g): | 613.2 |
| Meteorite Type: | Eucrite (unbrecciated) |
Macroscopic Description: Robbie Ann Score
Shiny black fusion crust with well-developed flow lines covers
one half of this pretty eucrite. The other surface is broken and
shows minor oxidation. The interior has coarse grained graphic
intergrowths of plagioclase and pyroxene. Some brown oxidation
is scattered throughout.
Thin Section (,5) Description: Brian Mason
The section shows a granular aggregate of pyroxene and plagioclase (grains up to 0.9 mm). The meteorite is unbrecciated, but the individual pyroxene crystals have been granulated. Microprobe analyses show essentially uniform compositions; pyroxene, Wo2-6 Fs60-63; plagioclase, An89-90. The meteorite is a eucrite.
| Sample No.: | GRO95534; GRO95535 |
| Location: | Grosvenor Mountains |
| Dimensions (cm): | 3.0 x 2.7 x 1.5; 3.2 x 2.5 x 2.7 |
| Weight (g): | 17.9; 53.8 |
| Meteorite Type: | Howardite |
Macroscopic Description: Cecilia E. Satterwhite
The exterior surfaces of these achondrite meteorites have smooth,
shiny black fusion crust over seventy five percent of their surface.
Areas where fusion crust has been plucked away reveal a gray matrix
. The interior reveals a gray fine-grained texture with abundant
white inclusions. A few green and black minerals are present.
Minor oxidation is present.
Thin Section (GRO95534,3; 95535,5) Description: Brian Mason
The sections are so similar that a single description will suffice; the meteorites are probably paired. They show a groundmass of comminuted pyroxene (orthopyroxene and pigeonite) and plagioclase (grains up to 0.2 mm), with a few larger mineral clasts and rare polymineralic clasts up to 2.5 mm across. Microprobe analyses show a wide range in pyroxene composition: Wo1-40, Fs20-60, En33-79, but with orthopyroxene clustered around Wo8Fs53 to Wo40Fs27 with fairly uniform En content. Plagioclase composition is An86-93. An SiO2 polymorph, probably tridymite, is present in accessory amounts. The meteorites are howardites.
| Sample No.: | GRO95544; GRO95545 |
| Location: | Grosvenor Mountains |
| Dimensions (cm): | 8.0 x 7.5 x 6.0;7.0 x 5.0 x 3.0 |
| Weight (g): | 626.0;142.1 |
| Meteorite Type: | L3 Chondrites (estimated L3.5) |
Macroscopic Description: Kathleen McBride
The exterior of these meteorites have thin, patchy fusion crust.
In some areas fusion crust has been weathered away. The interior
is dark brown with numerous chondrules. Chondrules are white to
yellow in color and measure 1 to 4 mm in size. Some appear rusty.
Metal grains are present and samples are very coherent and difficult
to break.
Thin Section (GRO95544,5;95545,4) Description: Brian Mason
The sections are so similar that a single description will suffice; the meteorites are probably paired. The sections show numerous chondrules and chondrule fragments, up to 2.4 mm across, in a black matrix containing small amounts of nickel-iron and troilite. The chondrules are mainly granular and porphyritic olivine and olivine-pyroxene, with a few radiating and crytocrystalline pyroxene. Microprobe analyses show olivine and pyroxene of variable composition: olivine, Fa1-20, mean Fa14; pyroxene, Fs1-28. The meteorites are classified as L3 chondrites (estimated L3.5).
| Sample No.: | GRO95555 |
| Location: | Grosvenor Mountains |
| Dimensions (cm): | 6.0 x 6.0 x 5.0 |
| Weight (g): | 250.6 |
| Meteorite Type: | Diogenite (unique) |
Macroscopic Description: Carol Schwarz
This specimen is angular in shape and greenish in color. There
are several penetrating fractures. The exterior is somewhat polished
with no fusion crust. The interior is greenish brown and crystalline
with coarse-grained green and dark minerals. (It is coarser than
PAT91501 (L7 Chondrite) and ALHA77005 (SNC) and contains no plagioclase.)
Thin Section (,2) Description: Brian Mason and Tim McCoy
The section shows a polygonal-granular aggregate of anhedral orthopyroxene,
the grains ranging from 0.3 to 2.4 mm across. Pyroxene composition
is essentially uniform, Wo2Fs24.. Accessory
phases include SiO2, chromite, an iron sulfide (probably
troilite), and weathering products of metal and troilite. The
composition is that of a diogenite, but the texture is unique;
it shows no sign of the brecciation and shock deformation characteristic
of other diogenites.
Aluminum-26 Activity: Dave Lindstrom
The sample was radioassayed for Al-26 because it had not fusion crust and might have been a terrestrial rock. Estimated Al-26 activity of 50±10 dpm/hg is similar to that of diogenites and other achondrites.