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Thiel Mountains 91700
Basic information Name: Thiel Mountains 91700
     This is an OFFICIAL meteorite name.
Abbreviation: TIL 91700
Observed fall: No
Year found: 1991
Country: Antarctica [Collected by US Antarctic Search for Meteorites program (ANSMET)]
Mass:help 256 g
Antarctic Meteorite Newsletter:  AMN 16(1)  (1993)  L4
Meteoritical Bulletin:  MB 76  (1994)  L4
NHM Catalogue:  5th Edition  (2000)  L4
MetBase:  v. 7.1  (2006)  L4
Recommended:  L4    [explanation]

This is 1 of 1709 approved meteorites (plus 4 unapproved names) classified as L4.   [show all]
Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Writeup from AMN 16(1):

Sample No.: TIL91700; 91702; 91703; 91704; 91708; 91711; 91721; 91723

Location: Thiel Mountains

Dimensions (cm): 6.0 x 5.0 x 3.5; 9 x 7 x 3; 9.5 x 5.5 x 5.3; 7 x 4 x 3; 8 x 6 x 3.5; 8.5 x 5 x 3; 7 x 6x3; 11 x5.5x2

Weight (g): 256.1; 304.7; 264.9; 234.7; 310.4; 276.3; 233.6; 264.6

Meteorite Type: L4 Chondrite


Macroscopic Description: Robbie Marlow and Carol Schwarz

Between 25% and 95% of the exteriors of these meteorites are covered with thin black fusion crust. The interiors show dark gray to black matrix with large oxidation haloes and heavy oxidation in places. Numerous inclusions range in size from <1 mm to 2 mm, many larger clasts were noted, one in particular is 0.9 x 0.5 cm in 91704.


Thin Section (91700.2: 91702.2: 91703.2:, 91704.2: 91708.2: 91711.2: 91721.2: 91723.2) Description: Brian Mason

The textures, mineral compositions, and degree of weathering shown by these sections are so similar that the meteorites can confidently be paired. The sections show a close-packed aggregate of chondrules, chondrule fragments, and occasional clasts, with minor subequal amounts of nickel-iron and troilite. Minor weathering is indicated by brown limonitic staining throughout the sections. Microprobe analyses show fairly uniform olivine compositions (Fa23-25) and variable pyroxene compositions (Fs15-25). The meteorites are classified as L4 chondrites, although the nickel-iron content appears to be higher than the normal for L-group chondrites. Additional members of this pairing group are: TIL91705, 91718, and 91720. Optical examination shows that TIL91701, 91709, and 91712 are also paired with these meteorites.


Data from:
  Table 2
  Line 5480:
Origin or pseudonym:Moulton Escarpment
Mass (g):256.1
Weathering grade:B
Fayalite (mol%):23
Ferrosilite (mol%):18-21
Comments:91700 pairing group
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References: Published in Antarctic Meteorite Newsletter 16(1) (1993), JSC, Houston
Published in Meteoritical Bulletin, no. 76, Meteoritics 29, 100-143 (1994)
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     Catalogue of Meteorites:   (85° 15'S, 91° 0'W)
     Recommended::   (85° 9' 55"S, 94° 35' 26"W)
Note: the NHM and MetBase coordinates are 34.8 km apart

     This is 1 of 40719 approved meteorites from Antarctica (plus 4494 unapproved names)
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