Antarctic Meteorite Newsletter, Volume 23, No. 2 - September 2000
Volume 23, No. 2 - September 2000

Table 4: Natural Thermoluminescence (NTL) Data for Antarctic Meteorites

Paul H. Benoit and Derek W.G. Sears

Cosmochemistry Group

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]

 

GRA 98006

EUC

7.1 0.4

GRA 98019

EUC

5.6 0.5

GRA 98037

EUC

6 2

GRA 98042

EUC

5.6 0.5

GRA 98043

EUC

3.0 0.7

GRA 98054

EUC

4.8 0.6

GRA 98055

EUC

6.9 0.6

     

GRA 98032

URE

n.d.*

     

GRA 98023

H3

62 4

GRA 98050

H3

40 4

     

GRA 98013

H4

82.1 0.3

GRA 98031

H4

50 1

     

GRA 98002

H5

140 2

GRA 98004

H5

16.4 0.2

GRA 98007

H5

55 3

GRA 98008

H5

7.3 0.1

GRA 98009

H5

55.9 0.3

GRA 98010

H5

92.9 0.6

GRA 98012

H5

1.4 0.1

GRA 98014

H5

176.1 0.3

GRA 98015

H5

40.7 0.1

GRA 98016

H5

37.0 0.3

GRA 98017

H5

139.8 0.3

GRA 98040

H5

14 2

GRA 98047

H5

63.2 0.2

GRA 98051

H5

47.6 0.3

     

GRA 98034

H6

32.0 0.6

GRA 98048

H6

34.3 0.5

     

GRA 98003

L5

23.8 0.1

GRA 98011

L5

60.9 0.1

GRA 98020

L5

48.5 0.1

GRA 98035

L5

103 6

     

GRA 98036

L6

1.0 0.1

GRA 98041

L6

19 5

GRA 98046

L6

36.6 0.2

GRA 98049

L6

9.5 0.1

QUE 97555

L6

3.8 0.1

     

QUE 97431

LL5

0.8 0.3

QUE 97433

LL5

12 2

QUE 97441

LL5

2.3 0.5

QUE 97490

LL5

4.4 0.2

QUE 97524

LL5

5.7 0.1

QUE 97525

LL5

3.2 0.4

QUE 97575

LL5

56.6 0.1

QUE 97612

LL5

8.2 0.3

*n.d. = natural and induced thermoluminescence below detection limits.

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 sample descriptions.

Induced TL sensitivity data and the shape of the induced TL glow curve suggest that GRA98023 and GRA98050 are subtype 3.6 and 3.7, respectively.

GRA 98041 (L6) has very low TL sensitivity and may be highly shocked.

Pairings confirmed by TL data:

Pairing not confirmed by TL Data

Pairings suggested by TL data: