Gwangju granite is largely found in the southern and southwestern part of Gwangju-Naju area. Composed of medium to coarse-grained granitic rocks (dark-gray), the area features low and gentle topography, resulted by constant weathering (Jung-bin Kim, 1990). Gwangju granite intrudes granitic gneiss and meta-sedimentary rocks, and is intruded by andesite of Mudeungsan and sedimentary rocks of the Neungju, overlying the rocks unconformably. The rock is classified as a hornblende-biotite granodiorite, porphyry granite, biotite granite, or two-mica granite based on the structure and castability of minerals. Gwangju granite features faults and slickensides and is a granite outcrop that can be easily accessed from the city. Gwangju granite is composed of Triassic-Jurassic hornblende-biotite granodiorite, Jurassic quarts diorite, Cretaceous quarts porphyry, and micrographic granite. There are two types of Triassic granite : biotite granite and granodiorite. Gwangju granite is the combination of these two granites (biotite granite and granodiorite).