Table 4: Natural Thermoluminescence (NTL) Data for Antarctic Meteorites
Mary Cummings, Paul H. Benoit, and Derek W.G. Sears
Arkansas-Oklahoma Center for Space and Planetary Sciences
University of Arkansas
Fayetteville, AR 72701 USA
The measurement and data reduction methods were described by Hasan et al. (1987, Proc. 17th LPSC, E703-E709; 1989, LPSC XX, 383-384). For meteorites whose TL lies between 5 and 100 krad, the natural TL is related primarily to terrestrial history. Samples with NTL <5 krad have TL levels below that which can reasonably be ascribed to long terrestrial ages. Such meteorites have had their TL lowered by heating within the last million years or so by close solar passage, shock heating, or atmospheric entry, exacerbated in the case of some achondrites by anomalous fading. We suggest meteorites with NTL >100 krad are candidates for unusual orbital/thermal histories (Benoit and Sears, 1993, EPSL, 120, 463-471).
| Sample | Class | Natural TL [krad at 250° C] |
|---|---|---|
GEO 99101 |
H4 |
47 ± 1 |
EET 99412 |
H5 |
43 ± 1 |
EET 99413 |
H5 |
10.9 ± 0.3 |
EET 99414 |
H5 |
61 ± 1 |
EET 99416 |
H5 |
9.9 ± 0.1 |
EET 99420 |
H5 |
1.2 ± 0.1 |
EET 99422 |
H5 |
97.7 ± 0.1 |
EET 99423 |
H5 |
1.5 ± 0.1 |
GEO 99100 |
H5 |
0.4 ± 0.1 |
MIL 99300 |
H5 |
27.1 ± 0.3 |
MIL 99303 |
H5 |
29.6 ± 0.5 |
MIL 99304 |
H5 |
0.5 ± 0.1 |
QUE 99003 |
H5 |
49 ± 1 |
QUE 99004 |
H5 |
70.2 ± 0.1 |
QUE 99008 |
H5 |
24.8 ± 0.1 |
QUE 99009 |
H5 |
64 ± 2 |
QUE 99014 |
H5 |
23.5 ± 0.1 |
QUE 99027 |
H5 |
60.6 ± 0.6 |
ALH 99505 |
H6 |
35.4 ± 0.7 |
EET 99410 |
H6 |
6.5 ± 0.1 |
EET 99411 |
H6 |
20.2 ± 0.3 |
QUE 99002 |
H6 |
34.5 ± 0.7 |
ALH 99506 |
L5 |
113.0 ± 0.5 |
EET 99424 |
L5 |
1.5 ± 0.1 |
MIL 99306 |
L5 |
51.2 ± 0.1 |
MIL 99309 |
L5 |
86.6 ± 0.8 |
MIL 99310 |
L5 |
38.0 ± 0.4 |
MIL 99319 |
L5 |
40.5 ± 0.4 |
MIL 99320 |
L5 |
42.8 ± 0.3 |
MIL 99323 |
L5 |
29.8 ± 0.5 |
QUE 99010 |
L5 |
112.0 ± 0.5 |
QUE 99029 |
L5 |
7 ± 2 |
EET 99409 |
L6 |
0.6 ± 0.1 |
GEO 99129 |
L6 |
0.6 ± 0.1 |
MIL 99305 |
L6 |
14.0 ± 0.1 |
MIL 99318 |
L6 |
8.3 ± 0.1 |
QUE 99028 |
L6 |
101 ± 1 |
MIL 99301 |
LL6 |
65.8 ± 0.1 |
MIL 99308 |
LL6 |
0.5 ± 0.1 |
EET 99400 |
HOW |
6.4 ± 0.5 |
The quoted uncertainties are the standard deviations shown by replicate measurements on a single aliquot.
COMMENTS: The following comments are based on natural TL data, TL sensitivity, the shape of the induced TL glow curve, classifications, and sample descriptions.
QUE 99029 and EET 99424 have very low TL sensitivity compared with other equilibrated ordinary chondrites and may be extensively shocked.
Pairings suggested by TL data: