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 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 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 certain achondrite classes by "anomalous fading".

Sample	Class	NTL [krad at 250° C]
GRO95566	C2	0

WSG95300	H3.3	6 ± 3
GRA95208	H3.7	33.9 ± 0.2

GRA95201	H5	153 ± 4
GRA95202	H5	34.8 ± 0.1
GRA95204	H5	20.4 ± 0.1
GRA95207	H5	17.1 ± 0.1
GRA95210	H5	0.16 ± 0.03
GRA95212	H5	50.0 ± 0.1
GRO95506	H5	17.9 ± 0.3
GRO95520	H5	109.7 ± 0.4
PRE95400	H5	103 ± 3

GRA95211	H6	20.2 ± 0.1
GRO95516	H6	88.2 ± 0.1
GRO95532	H6	65.7 ± 0.1
GRO95505	L3.4	5 ± 4

GRA95203	L5	46.8 ± 0.1

GRA95206	L6	40.0 ± 0.1
GRO95510	L6	65.5 ± 0.1
GRO95513	L6	7.9 ± 0.1
GRO95526	L6	31.8 ± 0.2
GRO95528	L6	7.3 ± 0.1
GRO95531	L6	0.80 ± 0.1

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 JSC and Arkansas group sample descriptions.

GRA95208 is confirmed as a type 3.7 (AMN 20:1).

GRO95505 and WSG95300, classified as type 3.6 and type 3.4 respectively (AMN 20:1), are type 3.4 and 3.3.