The geologic landscape formed through the weathering processes near the southwestern coast was investigated through three granites which are located in the Mt. Wolchul of Youngamgun, Mt. Cheongwan of the Jangheunggun in Jeollanamdo, and Mt. Geum in Namhaegun Kyongsangnamdo. The minerals in these granites consists of pink feldspar(perthite), quartz and plagioclase(<An50). The granites have a miarolitic cavity structure and a micrographic texture which indicate that the granites intruded into shallow depth of the crust. The Rb-Sr whole rock isotron age in between 71Ma and 93Ma corresponds to the Cretaceous period. The study area shows various geological landscape such as tor, kastle koppie, flared slops, domed inselberg, tafoni, gnamma and groove. Gnammas of the Gujeongbong on Mt. Wolchul and in the peak of Mt. Geum are reported in the previous study. The study found new well-developed gnammas in three areas ,Guryongbong on Mt. Cheongwan, Sajabong and Hyangrobong on Mt. Wolchul. More gnammas are expected to be found on the other granite. In the previous research, most gnammas first started from the joint line. This study, however, found that most gnammas originated from the miarolitic cavity in the ground and subaerial level, not on the joint line, of the cretaceous granite body. The initial small gnammas enlarged through the process of drying, wetting, freeze-thawing, flaking, and salt weathering.

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cretaceous granite, gnamma, miarolitic cavity structure, geologic landscape, Youngamgun Mt. Wolchul, Jangheunggun Mt. Cheongwan, Namhaegun Mt. Geum