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Derek Sears
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Bay Area Environmental
Research Institute/NASA Ames Research Center/University of Arkansas
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Backscattered electron,
thermoluminescence and CATHODOLUMINESCENCE
IMAGES OF A LARGE CHONDRULE IN SEMARKONA Three images of a large chondrule from the Semarkona chondrite. (a) Backscattered electron image. (b) Thermoluminescence image obtained by a CCD camera. (c) Cathodoluminescence obtained by a low-powered CL microscope. The luminescent area is not apparent in the BSE image, but the TL and CL are higher in the same outer regions of the chondrule mesostasis. Subsequent analysis by electron and ion microprobes showed the outer regions were higher in volatile elements and lighter in oxygen isotopes (in a non-mass-dependent way) relative to the interior. (Sears, 1974; Matsunami et al., 1993). |
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