Thermoluminescence constraints on the metamorphic, shock, and brecciation history of basaltic meteorites

Batchelor, J. D.; Derek, W G Sears

doi:10.1016/0016-7037(91)90077-i

Cited by 23 publications

(14 citation statements)

References 45 publications

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“…The hummocky structure of the CO3.0 and CO3.2 is not well understood, but probably represents a mixture of minerals including forsterite and the minerals found in refractory inclusions. Cathodoluminescence (CL) micrography of these meteorites is consistent with the TL being due to forsterite and refractory phases (Sears et al 1991), and the CL of Murchison (which has been studied in some depth) suggests that forsterite is abundant and luminescence in these meteorites although in a form not suitable for detection by TL . Most probably, the emission is at longer wavelengths than we can detect in our TL apparatus where heat filters are used to suppress black body radiation from the sample.…”

Section: Comparison Of Induced Tl Properties With Those Of Known Chonmentioning

confidence: 55%

“…4a) are unusual paired CM chondrites that produce TL. Sears et al (1991) suggested that this paired trio of MAC meteorites should be considered CM3.0, CM3.1, and CM3.1 chondrites, respectively, as many of their properties resembled those of CO3.0-CO3.2 chondrites.…”

Section: Comparison Of Induced Tl Properties With Those Of Known Chonmentioning

confidence: 99%

“…5a). The relative proportions of these and the overall TL sensitivity of the CV chondrites reflect changes caused by metamorphism (Keck and Sears 1987;Sears et al 1991). The refractory inclusions show similar trends in which the metamorphic differences appear to exist from one inclusion to another.…”

Section: Comparison Of Induced Tl Properties With Those Of Known Chonmentioning

confidence: 99%

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Characterization of Antarctic micrometeorites by thermoluminescence

Sedaghatpour

Sears

2009

Meteorit & Planetary Scien

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Abstract-In order to explore the nature and history of micrometeorites, we have measured the thermoluminescence (TL) properties of four micrometeorites, three cosmic spherules, and one irregular scoriaceous particle, that we found in a survey of 17 micrometeorites. These micrometeorites have TL sensitivities ranging from 0.017 ± 0.002 to 0.087 ± 0.009 (on a scale normalized to 4 mg of the H3.9 chondrite Dhajala). The four micrometeorites have very similar TL peak temperatures and TL peak widths, and these distinguish them from CI, most CM, CV, CO, and ordinary chondrites. However, the TL properties of these micrometeorites closely resemble those of the unusual CM chondrite MacAlpine Hills (MAC) 87300 and terrestrial forsterites. Heating experiments on submillimeter chips of a CM chondrite and a H5 chondrite suggest that these TL properties are have not been significantly affected by atmospheric passage. Thus we suggest that there is no simple linkage between these micrometeorites and the established meteorite classes, and that forsterite is an important component of these micrometeorites, as it is in many primitive solar system materials.

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Section: Comparison Of Induced Tl Properties With Those Of Known Chonmentioning

confidence: 55%

Section: Comparison Of Induced Tl Properties With Those Of Known Chonmentioning

confidence: 99%

Section: Comparison Of Induced Tl Properties With Those Of Known Chonmentioning

confidence: 99%

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Characterization of Antarctic micrometeorites by thermoluminescence

Sedaghatpour

Sears

2009

Meteorit & Planetary Scien

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“…It is also possible, of course, that either one of these mechanisms can be operative without the other. Maybe the induced TL is simply monitoring the diffusive loss of Fe from the feldspar just as seems to be the case with the eucrites [ Batchelor and Sears , , ]. The only evidence we have found for the increase in induced TL with age being due to glass crystallization is that the microlites might be increasing with age among the <20 ka samples, but there is no indication that this is true of the older samples.…”

Section: Discussionmentioning

confidence: 99%

“…In this case, a 100‐fold increase in induced TL correlates with metamorphism as inferred by the compositional heterogeneity of the pyroxenes in the meteorites [ Batchelor and Sears , ]. However, this increase in induced TL is because the feldspar in unmetamorphosed eucrites contains Fe, a well‐known quencher of luminescence, which diffuses out of the feldspar with increasing metamorphism [ Batchelor and Sears , ]. Thus, we have two mechanisms that could explain the May [, ] observation that induced TL increases with age, crystallization of the glass, and the diffusion of Fe out of the plagioclase.…”

Section: Introductionmentioning

confidence: 99%

Induced thermoluminescence as a method for dating recent volcanism: Eastern Snake River Plain, Idaho, USA

Sears

Sehlke

et al. 2017

JGR Solid Earth

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The induced thermoluminescence properties of 24 samples of basalts from volcanoes in the eastern Snake River Plain, Idaho, were measured as part of an investigation into the possibility of using this technique for dating purposes. The volcanic flows sampled ranged in age from 2200 years to ~400,000 years. The thermoluminescence (TL) sensitivity values obtained, i.e., maximum induced TL normalized to that of the Dhajala meteorite (where Dhajala = 1000), ranged from 1.6 ± 0.3 to 226 ± 15 and showed a correlation between log TL and age with an r2 value of 0.47. Thus, TL sensitivity values correlate with age in the manner expected, although there is a high level of scatter. We discuss various mechanisms for the correlation and scatter, particularly (1) the role of primary (igneous processes) and secondary (solid state processes), (2) composition of the plagioclase feldspar, and (3) weathering. The induced TL signal from feldspars, the mineral responsible for the TL, is strongly dependent on their composition, and correcting for this improved the correlation (r2 = 0.7). Variations in primary feldspar are affecting the data, but we find no evidence that weathering of the samples is important. Further work is required to explore the remaining causes for the scatter and the TL‐age trend. However, it is clear from the present study that induced TL has the potential for dating volcanism on the 2200 to 400,000 year time frame. This dating method, if successful, would be well‐suited to spacecraft use since it requires low mass and low power instruments with a low data demand.

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