Natural Thermoluminescence (NTL) Data for Antarctic Meteorites
Paul Benoit and Derek Sears
Cosmochemistry Group
Dept. of Chemistry and Biochemistry
University of Arkansas
Fayetteville, AR 72701
The measurement and data reduction methods weredescribed 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 below that which can reasonable be ascribed to long terrestrial ages. Such meteorites have had their TL lowered by heating within the past million years or so by close solar passage, shock heating, or atmospheric entry, exacerbated, in the case of certain achondrite classes and possibly enstatite chondrites, 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).
NTL
[krad at
Sample Class 250 deg. C]
LON 94101 C2 0.0 ±0.1
LON 94102 C2 0.0 ±0.1
LON 94100 E6 2.4 ±0.2
QUE 94200 HOW 2.3 ±0.4
QUE 93069 LUN 0
QUE 94281 LUN 0.21±0.01
ALHA77009 H4 30 ±1
ALHA77208 H4 27.9 ±0.1
ALHA77232 H4 33.1 ±0.2
ALHA78134 H4 64.8 ±0.2
ALHA77182 1.0 ±0.1
ALHA77268 H5 1.2 ±0.4
ALHA78128 H5 4.4 ±0.2
ALHA78194 H5 42.5 ±0.3
ALHA79025 H5 0.33±0.07
LEW 93802 H5 12.1 ±0.1
QUE 93013 H5 3.1 ±0.3
ALHA76006 H6 0.4 ±0.1
ALHA77285 H6 31.2 ±0.1
QUE 93014 H6 33.9 ±0.9
LEW 93800 L5 9.9 ±0.1
QUE 93020 L5 11.6 ±0.1
QUE 93021 L5 161 ±1
QUE 93197 L5 2.1 ±0.5
QUE 93216 L5 12.7 ±0.1
QUE 93231 L5 3.5 ±0.5
QUE 93245 L5 6.0 ±0.1
QUE 93247 L5 0.35±0.04
QUE 93251 L5 8.2 ±0.1
QUE 93307 L5 10.2 ±0.1
QUE 93330 L5 1.2 ±0.1
QUE 93370 L5 6.5 ±0.1
QUE 93600 L5 0.71±0.02
QUE 93683 L5 10.6 ±0.1
QUE 93696 L5 13.7 ±0.1
QUE 93697 L5 1.8 ±0.1
QUE 93699 L5 5.2 ±0.4
QUE 93706 L5 15.3 ±0.1
QUE 93707 L5 3.9 ±0.7
QUE 93015 L6 4.8 ±0.2
QUE 93019 L6 25.9 ±0.1
QUE 93080 L6 1.3 ±0.1
QUE 93410 L6 1.5 ±0.8
The quoted uncertainties are the standard deviations shown by replicate measurments on a single aliquot.
COMMENTS: The following comments are based on natural TL data, TL sensitivity, the shape of the induced glow curve, classifications, and JSC and Arkansas group sample descriptions.
QUE93015 (L6) and QUE93410 (L6) may be heavily shocked.
QUE94200 (HOW) has a TL sensitivity similar to Kapoeta and Binda (GCA 55, 3831-3844).
1. Pairings (Confirmations of pairings):
- L5: QUE93020 with QUE90207 group (AMN 18:1 and 15:2).
- H4: ALHA77208 and ALHA77232 with ALHA77004 group (Meteoritics 29, 100-143)
2. Additional pairings suggested by TL data:
- H4: ALHA78134 may be paired with ALHA77262 (Meteoritics 29, 100-143)
- H5: ALHA78047 and ALH88028 with ALHA77268 (AMN 17:1; JGR 98, 1875-1888)
- H5: ALH86601 with ALHA78128 (Meteoritics 29, 100-143).
- H5: LEW93802 may be paired with LEW85464 (JGR 97, 4629-4647).
- H5: QUE93013 with QUE93028 group (AMN 18:2).
- H6: QUE93014 with QUE90223 group (AMN 18:1).
- L5: LEW93800 may be paired with LEW85385.
- L5: QUE93197, QUE93231, QUE93247, QUE93330, QUE93600, QUE93697, QUE93699, and QUE93707 with QUE90205 group (AMN 15:2).
- L5: QUE93020, QUE93245, QUE93251, QUE93307, QUE93370, QUE93683 and QUE93696 with QUE90207 group (AMN 15:2).
- L5: QUE93216 with QUE93706, and possibly with QUE90207 group (AMN 15:2).
- L6: QUE93015 is possibly paired with QUE87400.