여수의 암석 분포와 지질경관의 형성

Abstract

The Yeosu area is situated in the southern part of the korea peninsula, and is geologically constructed by sedimentary, and the volcanic and igneous rocks created in the Cretaceous period. The Gyeongsang strata built up by the Gyeongsang basin is made up of lacustrine deposits(Sindong group) and volcanic rocks (Yucheon group) of the area. The Yucheon group of the area can be divided into three formations; Andesite and andesitic tuff, Sinseongri-Formation, and Rhyolite and rhyolitic tuff. The igneous rocks of the area consist of biotite granite, micrographic granite, and dyke rock. Many steep and rocky coasts, headlands, sea cliffs, sea arches and stacks of the studied area have been greatly changed, due to the sea wave erosion. The wave-cut platforms(terrace) of Sado are a horizontal bench of rocks formed beneath the surf zone, as the coast retreats it by sea wave erosion. Joints are one of most commonly observed rock structure in the area. A joint set is built where joints are approximately parallel to one another. Columnar joints like the turtleback of Hyangilam involves hexagonal columns which take into form as a result of the tension and contraction of the hot volcanic material layer(the cooling and solidifying). The three set of joints in the Geomundo lighthouse and other islands have formed in response to the horizontal compressive stress. Vertical joint sets in the Baekdo and other island are associated with tectonic uplifts of this region.