The study area, Khao Phloi Waen and its vicinity, is located in Amphoe Tha Mai, and Amphoe Muang, Changwat Chanthaburi. Landforms in this area can be divided into 4 units; the mountainous and hilly area of the country rocks, the piedmont plain, terrace and floodplain, and tidal flat. The surficial deposit is composed of the residual deposit of the country rocks and sediments from various processes. By the banka drilling, alluvial deposit is deposited with colluvium and some is overlain by mangrove deposit. By the difference of sedimentary character, it indicates to the depositional environments and processes changed from fluvial to marine. Besides, it is found weathered basalt that underlies mangrove deposit. It might continue from Khao Phloi Waen. By the correlation, there is a sedimentary layer underlies this basaltic layer. It is expected to be the weathering zone of bedrocks or fluvial sediments. In addition, corundum deposit in this area was mostly associated with basaltic residual weathering zone. Corundum was found with the associated minerals such as pyroxene, garnet, zircon, spinal, magnetite, ilmenite, and olivine. For the potential of corundum deposit, there are 2 types of deposit in the area; residual weathering of basaltic rock and placer deposit in the gravel bed. Lastly, the total area of potential corundum deposit in both types is about 21.58 square kilometers.
