[SCG60-P03] Clay minerals from Akeshi mine, Minamikyushu City, Kagoshima Prefecture, Japan
Keywords:Akeshi Mine, Gold deposit, Clay Minerals, Interstratified Clay Minerals
The analyzed boring cores were obtained near the mining areas, and 30 samples from the 70-90 m depth from the H27-2-2 core, and 19 samples from 90-110 m depth from the H29-1-1 core. Collected samples were investigated using the polarization microscopy, X-Ray Diffraction (XRD) analysis, SEM-EDS analysis and TEM-EDS analysis in order to define the composing minerals and clay minerals.
Drilling core samples were classified into 4 groups according to the amount of quartz and constituent minerals. Group 1 and 2 was rich in quartz and contains minor kaolinite. Group 3 in composed of kaolinite and smectite. Group 4 includes chlorite, kaolinite, and interstratified clay mineral of chlorite and smecite, and H29-1-1 core was richer in kaolinite. In the results of chemical analysis by TEM-EDS, the clay minerals in altered andesite from group 4 was Fe-rich chlorite (chamosite), however, in SEM-EDS, the obtained composition was intermediate of clinochlore and chamosite. In TEM-EDS, illite-smectite interstratified clay minerals, (K0.47(Mg0.37 Fe0.37 Al1.62)2.36(Si3.23 Al0.77)4O10(OH)2, was observed.