A Study on the Iron Compounds of Cinder Cones' Scoria in the Southern Area of Halla Mt., Jeju Island

This study reviewed mineral composition on Scoria samples of this area, atomic value state of oxidized steel, and magnetic property in order to look into characteristics of scoria that was distributed in southern area of mountainous areas, Halla Mt. of Jeju Island. By XRD analysis, mineral composition was confirmed, and characteristics of iron compounds existed in samples were investigated through Mossbauer spectroscope. Composing minerals could be learnt as feldspar basalt from XRD analysis because composting minerals were composed of quartz and feldspar anorite mainly, and iron compounds were made up with olivine, pyroxene, ilmenite, hematite, and magnetite. By Mossbauer spectroscope analysis on these iron compounds. it consisted of hematite and magnetite which showed hyperfine magnetic field of sextet mostly, and also doublet by olivine, pyroxene, ilmenite could be seen as appearing together. As a result of comparing with samples of Jeju western area having been announced in previous research, I.S. and Q.S. values of olivine, Fe2+, were 122 mm/s and 3.09 similar to 3.13 mm/s respectively, and a fact could be known that Fe2+ olivine having similar structure each other was contained, and the ratio of Fe3+/Fe-tot. was 85.90 similar to 92.82%. From these findings, it was able to be presumed that they belonged to samples having been formed on the land at the same period of time. As a result of investigating area ratio of tetrahedron ( A site) and octahedron (B site) regarding magnetite in samples, it was turn out to be 0.22 similar to 0.55 less than 2.