## 4 Petrography and Geochemistry
### Mineral Composition and Texture  
To identify the minerals composing the rocks under study and analyze their structures, we performed X-ray diffraction (XRD) analysis and created thin sections for observation using polarizing microscopes. The XRD analysis revealed characteristics of the rocks that show discernible associations of the composing minerals (Figure 5). Although quartz, mica, plagioclase, and garnet were found in all gneiss specimens regardless of the remains excavated and the presumed-provenance sites, the gneiss excavated from Seokchon-dong (SGN) differs by its notably different mica diffraction peak and by the absence of alkali feldspar (Figure 5). The mineral composition for the schist, excavated from Gamil-dong (GSC) and that for schist from the presumed-provenance sites (PSC) both include hornblende, quartz, garnet, and plagioclase. However, schist excavated from Bangi-dong (BSC) had no hornblende, and the quartz and mica each had notably different diffraction peaks from GSC and PSC. That is, the schists differed, with the BSC schist showing the same pattern as the gneiss instead of matching the other schists' peaks (Figure 5). Within each rock type, the mineral compositions of the quartzites (only quartz), amphibolites, and diabases did not differ regardless of the excavation and collection sites. Figure 5: Result of X-ray powder diffraction analysis. Sample names are the same as in Table 1. Chj, chlorite, M; mica, Ho; hornblende, Q; quartz, Pl; plagioclase, Af; alkali-feldspar, Py; pyroxene, Ga; garnet, Ma; magnetite. The mineral composition determined in thin sections matched that found by XRD, but observation by polarizing microscope also revealed the different textures across rock types (Figure 6). The genesis typically showed leucocratic zones composed of granoblastic quartz and melanocratic zones composed mainly of biotite. In the geniss from Bangi-dong (BGN) and Deamo Mountain (PGN-3), alkali feldspar was observed along with quartz composing the leucocratic zones. The gneiss excavated from Seokchon-dong (SGN) was observed to have narrower leucocratic and melanocratic mineral zones. The difference among the gneiss was more obvious where we found large garnets (Figure 6). By its 1 mm grain size and greater granularity, schist was found to differ from gneiss, most notably with the Bangi-dong schist (BSC), whose major component minerals are quartz and mica. Additionally, although both the Gamil-dong schist (GSC) and schist from the presumed-provenance sites (PSC) contain homblende, plagioclase, and quartz, GSC samples contain somewhat-larger hornblende and PSC has more plagioclase. Quartzite excavated from the Gamil-dong remains (GQU) and collected from the presumed-provenance site (PQU-1) both exhibit granoblastic texture, and similar granularity of the quartz crystals, whereas quartzite from Seokchon-dong (SQU) has a somewhat different quartz granularity and texture. It is considered that quartzite from Seokchon-dong (SQU), which has a general sedimentary phase, and Gamil-dong (GQU) and provenance site (PQU-1), where distinct metamorphic structures are observed, are of different origins. Although the amphibolite excavated from Seokchon-dong (SAM) has granular felsic mineral across the fine-grained hornblende, the amphibolite excavated from Gamil-dong (GAM) shows characteristics similar to the amphibolite schist in other areas that was found to show directionality. The GAM sample, the amphibolite collected from Cheonma Mountain (PAM-1), showed an amphibole schist structure, with aligned hornblende crystals 1 mm and larger separating the felsic minerals. Thus, the studied amphiboles have similar composition but only Seokchon-dong amphibolite (SAM) has different structure. The diabase, found only in Gamil-dong, contains hornblende, pyroxene, and magnetite, as XRD results suggest for diabase both excavated from the remains (GDI) and collected from the presumed-provenance sites (PDI).