Thermoluminescence and the origin of the dark matrix of Fayetteville and similar meteorites

Photomosaics of the cathodoluminescence of 60 sections of meteorites and lunar samples

“…These are breccias with clasts of normal material sitting in a matrix of material rich in solar wind noble gases. What is remarkable about these images is that the light clasts and dark matrix look so similar in CL, a clear indication that the matrix is produced by comminuting the clasts, rather than being a new kind of primitive ordinary chondrite material like Semarkona [Haq et al, 1989;DeHart and Sears, 1988]. Figures A29 --A46) [18] The accompanying auxiliary material contains CL photomosaics of Allan Hills 84206 (EH3, Figure A29), Allan Hills 84170 (EH3, Figure A30), Pecora Escarpment 91085 (EH4, Figure A31), Pecora Escarpment 91238 (EH4, Figure A32), Saint-Sauveur (EH5, Figure A33), Lewis Cliff 88180 (EH5, Figure A34), Allan Hills 85119 (EL3, Figure A35), MacAlpine Hills 88184 (EL3, Figure A36), MacAlpine Hills 88136 (EL3, Figure A37), Thiel Mountains 91714 (EL5, Figure A38), Reckling Peak 80259 (EL5, Figure A39), Allan Hills 81021 (EL6, Figure A40), Atlanta (EL6, Figure A41), Khairpur (EL6, Figure A42), Lewis Cliff 88135 (EL6, Figure A43), Lewis Cliff 87119 (EL6, Figure A44), Lewis Cliff 87223 (EL3 anomalous, Figure A45), Happy Canyon (EL anomalous, Figure A46).…”

“…These are breccias with clasts of normal material sitting in a matrix of material rich in solar wind noble gases. What is remarkable about these images is that the light clasts and dark matrix look so similar in CL, a clear indication that the matrix is produced by comminuting the clasts, rather than being a new kind of primitive ordinary chondrite material like Semarkona [ Haq et al , 1989; DeHart and Sears , 1988].…”

The irradiation history of the Ghubara (L5) regolith breccia

“…This heating was localized since the Ghubara BM 1954/1956 individuals did not lose all oftheir 4He. Ifsuch heating occurred on the parent body prior to the impact that sent the Ghubara meteoroid earthward, heated (8M 1958) and less heated (BM 1954) chondrite regolith breccias varies from 1.0 (immature) to 0.1 (highly mature) in a log-linear fashion and correlates with other maturity indices, such as concentrations of volatile trace elements and carbon (Haq et al, 1989). The TL sensitivity ratio for Ghubara near 0.8 indicates a rather immature regolith breccia, consistent with the similarities of the induced TL peak temperature and peak width data for clasts and matrix (Fig.…”

“…TL peak temperature and width in cho ndrites are governed by thermal history (Haq et al, 1989) and induced peaks tend to narrow and mo ve to higher temperatures for severely annealed chondrites. For mature regoliths, the matrix exhibits broader peaks at lower peak temperatures compared to the clasts.…”

“…Regolith maturity can be estimated from induced TL (Haq et al, 1989) which increases during repeated impacts and turnover. As regolith matures, concentrations of solar wind implanted elements and solar-flare particle tracks increase and the mean particle size, particularly of the host material, decreases (Bunch and Rajan , 1988).…”