Cathodoluminescence study of Calcite in Martian meteorite T. Nakazato, M. Kayama, H. Nishido, K. Ninagawa, A. Gucsik, and Sz. Bérczi Research Institute of Natural Science, Okayama University of Science Department of Applied Physics, Okayama University of Science Max Planck Institute for Chemistry, Department of Geochemistry Eötvös University, Institute of Physics, Dept. G. Physics, Cosmic Materials Space NASA

Introduction CL and Raman spectroscopy were carried out on Dhofar 019 for origin of calcite. NASA

SNC : Martian meteorites Nakhlite Shergottite Chassignite Olivine bearing Basaltic Shergottite Augite, Pigeonite, Maskelynite Lherzolitic Shergottite Olivine, Pyroxene Shergottite 1865 India Shergotty Nakhlite 1911 Egypt Nakhla Chassignite 1815 France Chassgny Shergottite

Classification : Olivine bearing Basaltic Shergottite Constituent minerals : Pyroxene, Olivine, Maskelynite, merrillite and calcite Shock pressure : 30 GPa or more Formation age : ~ 500Ma Exposure age : ~ 15 million years Finding : Oman desert Weight : 1,056 g No fusion crust Photograph of Dhofar 019 Sample (Dhofar 019) Dhofar region

5mm Color CL images of Dhofar 019 Color CL image of Dhofar 019 : measured area Vein S L

measurement condition 15kv, 1.0nA CL spectra of calcite ( S and L ) S L BSE image of calcite (S, L) CL spectra of calcite (S and L)

BSE image of calcite (Vein) CL spectrum of calcite ( Vein ) Vein CL spectrum of calcite (Vein) measurement condition 15kv, 1.0nA

BSE image of calcite (Vein) CL spectra of calcite S L BSE image of calcite (S and L) Vein CL spectra of calcite in Dhofar019 and terrestrial calcite

Raman spectra of calcite Raman spectra of calcite in Dhofar019 and terrestrial calcite measurement condition light source : Ar-laser, 514.5nm power : 400 mW

Terrestrial (cm -1 ) Vein (cm -1 ) S (cm -1 ) L (cm -1 ) Raman peak shift of calcite Wave numbers of Raman peaks

Terrestrial (cm -1 ) Vein (cm -1 ) S (cm -1 ) L (cm -1 ) Raman peak shift of calcite Wave numbers of Raman peaks

Conclusion CL spectra Calcite in Dhofar 019 shows different spectra from terrestrial one. Raman spectra Calcite in Dhofar 019 show weaker Raman peak than terrestrial one. Calcite in Dhofar019 Martian origin

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