Meteorites

            The meteorites in this suite of samples were classified into the following main groups.

 

1.   Gabbro   

Agoult        fine grained gabbro (intergrowth of plagioclase and clinopyroxene with minor

sphene.

2.   Orthopyroxene-rich breccia, in part spheroidal, with abundant interstitial patches of native

iron and pyrrhotite(?); some spheroids have spinifex-like textures.  Many are

oxidized, with hematite-limonite replacement of native iron and pyrrhotite(?) and in fractures.

Dimmit 1                   native iron and pyrrhotite altered moderately to oxide

         Roosevelt County      native iron and pyrrhotite altered strongly to oxide

Forrest B1

Kunya Urgench          native iron and pyrrhotite relatively fresh

Umbarger                   native iron and pyrrhotite altered moderately to oxide

NWA1084-CR2        native iron and pyrrhotite altered moderately to oxide

NWA -984 LL4 -      native iron and pyrrhotite altered strongly to oxide

NWA002-EL6           native iron and pyrrhotite altered strongly to oxide

NWA 399                  not brecciated, native iron and pyrrhotite altered moderately to oxide

Selma H4                   pyrrhotite altered moderately to oxide

3.   Dunite/Peridotite

Suizhou                       dunite/peridotite, with scattered coarser grains of orthopyroxene in

                                   olivine, abundant, relatively fresh native iron and pyrrhotite(?).

4.     Banded /Peridotite/Dunite/Norite

Bondoc ME5                sharply banded with layers as follows from one end to the other:

1) peridotite: megacrysts of orthopyroxene intergrown with much

finer grained olivine

2) extremely fine grained dunite

3) norite/anorthosite: plagioclase in part with megacrysts of

orthopyroxene

                                             4) abundant native iron and lesser pyrrhotite, mainly replaced by

hematite/limonite; abundant late veinlets of hematite-limonite.

 


List of Photographs

Photo  Section     Description
1 (view) NWA1084-CR2 

spheroidal, granular orthopyroxene with interstitial patches of native

iron (secondary limonite/hematite).

Plane light.  Length of Photo (LOP) 2.9 mm.           

2 (view) NWA1084-CR2   

slightly offset from Photo 1: Reflected light.  LOP 2.9 mm.

3 (view) NWA002-EL6 

disseminated native iron, pyrrhotite in orthopyroxene-rich matrix;

abundant secondary limonite/hematite veinlets. 

Reflected light.  LOP: 1.6 mm.

4 (view) AGOULT 

gabbro: plagioclase-clinopyroxene-(ilmenite-pyrrhotite)

Plane light.  LOP: 1.60 mm

5 (view) NWA984-LL4   

spinifex texture in orthopyroxene spherules; surrounded by matrix of clinopyroxene.  Plane light.  LOP: 2.9 mm. 

6 (view) NWA984-LL4   

spherulitic texture, orthopyroxene and olivine.

Crossed nicols.  LOP: 2.9 mm.           

7 (view) NWA984-LL4   

contact, very fine grained dunite with porphyritic norite

(orthopyroxene megacrysts with interstitial plagioclase);

hematite/limonite on fractures. Crossed nicols. LOP: 2.9 mm.  

8 (view) NWA399 

peridotite with patches of native iron, pyrrhotite(?)

Reflected light.  LOP: 2.9 mm.

9 (view) Suizhou

peridotite: olivine with patches of orthopyroxene and interstitial native

iron and pyrrhotite.  Crossed nicols. LOP: 2.9 mm.

10 (view) Suizhou  

interstitial pyrrhotite, native iron, magnetite in peridotite (olivine and orthopyroxene).  Reflected light.  LOP: 2.9 mm.

11 (view) Kunya-Urgench 

pyroxenite (large subradiating patch in finer grained groundmass);

abundant interstitial native iron, minor pyrrhotite.

Reflected light.  LOP: 2.9 mm.

12 (view) Umbargor  

gabbro: clinopyroxene-plagioclase with patches of oxidized opaque.

Crossed nicols.  LOP: 2.9 mm.

13 (view) Dimmit 1  

Spheroid of orthopyroxene with unusual sieve texture.

Plane light.  LOP: 2.9 mm. 

14 (view) Dimmit 1   

spheroidal patches of orthopyroxene in brecciated groundmass of

much finer orthopyroxene with patches of hematite/limonite; veinlike

zone of orthopyroxene with rind of hematite/limonite.

Plane light:  LOP: 1.60 mm.

15 (view) Dimmit 1  

Patch of extremely fine grained pyrrhotite and massive native iron in

brecciated orthopyroxene; late replacement and veinlets of

hematite/limonite.  Reflected light.  LOP: 2.9 mm.

16 (view) Forrest B-1  

patches of orthopyroxene showing altered exsolution lamellae

(possibly original pigeonite), disseminated patches of native iron

(locally replaced by hematite).  Plane light.  LOP: 2.9 mm

17 (view) Roosevelt County 89-1

megacryst of orthopyroxene showing warped

lamella.  Crossed nicols.  LOP: 2.9 mm.

18 (view) Selma H-4    

orthopyroxene breccia, spheroids of orthopyroxene with delicate

textures; interstitial native iron altered moderately to hematite.

Plane light.  LOP: 2.9 mm.