Type 3 ordinary chondrites

Figure 7. Details from four photomosaics of the cathodoluminescence of type 3 ordinary chondrites. (a) Detail from Semarkona (top, horizontal field of view 5.0 mm). (b) Detail from Bishunpur (middle, horizontal field...

The detailed CL trends displayed by the type 3 ordinary chondrites are therefore a unique means of determining not only the mineralogical factors affecting TL sensitivity, but they also provide a new means of examining the compositional (by complementary electron microprobe analysis) and structural (i.e. petrographic) changes associated with metamorphism-induced changes in CL properties. In the next few sections we summarize the CL properties of the ordinary chondrites. 

Figure 12. Plot of peak temperature against peak width for samples of Allan Hills A77214 annealed in a dry nitrogen atmosphere at atmospheric pressure, and at the temperatures indicated, for 100 h. Type 3 ordinary chondrites (c.f. Figure 3) are plotted as dots. (Reprinted with permission from Ref. 9. Copyright 1985 Pergamon Press.)...

Primitive breccias Type-3 ordinary chondrite breccias... 

Sears D. W. G. and Weeks K. S. (1991) Chemical and physical studies of type 3 chondrites 2. Thermoluminescence of sixteen type 3 ordinary chondrites and relationships with oxygen isotopes. Proc. 14th lunar Planet. Sci. Conf. Part 1 J. Geophys. Res. 88, B301-B311. 

Nagahara H. (1984) Matrices of type 3 ordinary chondrites— primitive nebular records. Geochim. Cosmochim. Acta 48, 2581-2595. 

Rubin A. E., Sailer A. L., and Wasson J. T. (1999) Troilite in the chondmles of type 3 ordinary chondrites implications for chondmle formation. Geochim. Cosmochim. Acta 63, 2281-2298. 

Sears D. W. G., Batchelor D. J., Lu J., and Keck B. D. (1991) Metamorphism of CO and CO-like chondrites and comparisons with type 3 ordinary chondrites. Proc. NIPR Symp. Antarct. Meteorit. 4, 319-343. 

Krot A. N., Zolensky M. E., Wasson J. T., Scott E. R. D., Keil K., and Ohsumi K. (1997b) Carbide-magnetite assemblages in type-3 ordinary chondrites. Geochim. Cosmochim. Acta 61, 219-237. 

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