Antarctic Meteorite Newsletter, Volume 24, No. 2 - September 2001
Volume 24, No. 2 - September 2001

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: