Cathodoluminescence and Raman spectroscopic study of maskelynite in

Cathodoluminescence and Raman spectroscopic study of maskelynite in shergottite (Dhofar 019) and experimentally shocked plagioclase M. Kayama, T. Nakazato, H. Nishido, K. Ninagawa, A. Gucsik, and Sz. Bérczi

Introduction Dhofar 019 : olivine-bearing basaltic shergottite Badjukov D. D et al. (2001) Taylor L. A et al (2002) Dhofar 019 shocked in the range of 30 -35 GPa judging from the formation of maskelynite Qualitative estimation of shocked pressure

In this study CL and Raman measurement have been carried out on 1. Experimentally shocked plagioclase to characterize their CL behavior and to clarify an effect of shock pressure 2. Maskelynite in shergottite (Dhofar 019) to estimate its shock pressure

Experimentally shocked plagioclase Sample: single crystal plagioclase (Ab 60 An 40) from Norway Experiments: shocked by single-stage light-gas gun at 20, 30 and 40 GPa Measurements: polarized microscopic observation, EPMA analysis and CL and Raman spectroscopy

Meteorite Dhofar 019 classification : olivine-bearing basaltic shergottite constituent : subhedral grains of pyroxene, olivine, and maskelynite (An 38 -68). 5 mm Micrograph of Dhofar 019 5 mm Color CL image of Dhofar 019

CL spectra of experimentally shocked plagioclase

CL spectra of experimentally shocked plagioclase Lattice defect Al-O--Al Mn 2+ Fe 3+ CL spectra of experimentally shocked plagioclase

CL spectra of experimentally shocked plagioclase Lattice defect STE Al-O--Al Mn 2+ Fe 3+ CL spectra of experimentally shocked plagioclase

Raman spectra of shocked plagioclase peak Intensity 0 > 20 > 30 > 40 (GPa) Alteration of structural configuration related to luminescence center Raman spectra of shocked plagioclase

Peak shift in yellow region (Mn 2+) 0 GPa : 560 nm (yellow) ･ low strength of crystal fields ･ tetrahedral site 20, 30 and 40 GPa : 630 nm ･ high strength of crystal fields ･ octahedral site Destruction of TO 4 framework caused by shock pressure

PDFs produced by experimentally shock pressure A B (A) Panchromatic CL image of plagioclase shocked at 40 GPa and (B) 3 D Raman intensity map

CL images of maskelynite in Dhofar 019 A 5 mm B C 0. 5 mm (A) Color CL image of Dhofar 019, (B) of maskelynite and (C) panchromatic CL image of maskelynite

CL spectra of maskelynite Blue emission CL spectra of maskelynite

CL spectra of maskelynite Blue emission STE Fe 3+ CL spectra of maskelynite

CL spectra of maskelynite Blue emission CL spectra of shocked plagioclase and maskelynite

Raman spectra of maskelynite Raman spectra of shocked plagioclase and maskelynite

Conclusion Experimentally shocked plagioclase ･ CL intensity decreases with an increase of shock pressure. ･ Shock-induced pressure causes the alteration of structural configuration related to luminescence center. New application of CL to estimation of shock pressure Maskelynite in Dhofar 019 ･ Maskelynite in Dhofar 019 have similar CL and Raman features to experimentally shocked plagioclase at 40 GPa. Shock pressure induced on Dhofar 019 at ~40 GPa

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