Japan Geoscience Union Meeting 2015

Presentation information


Symbol S (Solid Earth Sciences) » S-CG Complex & General

[S-CG58] Petrology, Mineralogy and Resource Geology

Mon. May 25, 2015 6:15 PM - 7:30 PM Convention Hall (2F)

Convener:*Akira Miyake(Department of Geology and Mineralogy, Graduate School of Science, Kyoto University), Toshiaki Tsunogae(Faculty of Life and Environmental Sciences (Earth Evolution Sciences), University of Tsukuba), Koichiro Fujinaga(Department of Systems Innovation, School of Engineering, University of Tokyo), Nobutaka Tsuchiya(Department of Geology, Faculty of Education, Iwate University)

6:15 PM - 7:30 PM

[SCG58-P13] In-situ observation of formation process of carbon-rich minerals in several sites of Yamaguchi,Japan.

*Yasunori MIURA1 (1.Yamaguchi, Visiting Univ.(In & Out))

Keywords:High-pressure carbon, Basalt, In-situ observation, Phologopite, Fluid solidified, Tube-like texture

1. Characteristics of carbon minerals: Carbon-bearing minerals are significant minerals to show the detailed formation process. Dynamic samples might elucidate new information of micro- to macro-carbon minerals, which are main purposes of the present paper [1-4].

2. Carbon-rich minerals from Yamaguchi Prefecture: Present carbon-bearing samples are used from three sites (Yamaguchi) and one site (Shimane) to compare dynamic formation processes[1-4].

3. Microscopic observation of carbon-containing minerals: Microscopic carbon-bearing minerals are obtained at the following six location-samples as follows [2-4].

1) Point A: Historical sample-site of basalt with phlogopite and feldspar contains microscopic carbon-bearing grains quenched as flake texture found in this study.
2) Points B: Basalt with phlogopite and feldspars shows more detailed grains and texture with tube-shaped texture with progressive change of carbon-contents. The present observation is new result to be found as carbon-separated concentrations during fluid-solid reactions shown as flake quenched texture.
3) Points C: Basalt phlogopite mica and feldspar shows carbon-bearing materials with quenched flake texture and tube-like textures.
4) Points D: Basalt with phlogopite minerals contains carbon-bearing grains with flake and tube-like textures.
5) Point E: Basalts with feldspar minerals (without any phlogopite) shows carbon-bearing grains on feldspar minerals.
6) Points F: Carbon-rich grains can be found separately on feldspar surface (without phlogopite).

4. Identification of carbon minerals: Carbon-rich grains from point B have been investigated by X-ray diffraction and Raman Spectroscopy, where the characteristics of high pressure-type carbon minerals(diamond-like) have been obtained in this study.

5. Formation of high-pressured carbon minerals: Dynamic process and tube-like texture indicate carbon-separation from carbon-bearing minerals during shock wave processes of volcano and impact process.

6. Summary: Carbon-rich grains of high-pressure form (microscopic diamond) are obtained on the Yamaguchi samples (grain B) compared with other samples in Japan, where carbon-separation and concentration can be developed along solidified tube-like and fluid-like process with quenching found in the study.

References: [1] Miura Y. (2007): Front. Mineral Sci. (Cambridge Univ.), 223. [2] Miura Y. (2008): Am. Geo. Union, pp.1. EOS Trans, AGU, 89 (53), MR33-B1861. [3] Miura Y. (2012-2014): Japan Journal of Geological Society (Osaka, Tohoku and Kagoshima Universities), pp.1. [4] Miura Y. (2014): Inter. Mineral. Assoc. 2014 (Johannesburg, SA), 689.