釜山市 梵魚寺 周邊의 Block Field에 關하여

Abstract

The studied Bomosa Temple block field on the northern mountain slope of Busan city is 500 meters long and 750 meters wide. The block field consists of angular or round boulders of the Gumjeong-San mountain granite which are in averege 2~3 meters long(in rare occurrence 6 meters). The blocks were derived from strongly jointed granite cliffs, tors or weathered bedrock on this mountain area and were transported downslope over the Gumjeongsan mountain granite. The upper slope of this block field is 15~23 degrees and the lower erosion surface is veneered with the bouldery materials and interstitial fine matrix. The adjacent vegetated slope which is covered by block field has, gentler slope (7°) than the upper slope of block field. Tabular blocks have an imbricated structure in which the blocks dip upslope and its long axis parallel with the direction of flow. The blocks are poorly sorted with coarser materials at the surface. Block fields are obviously stable now an no longer in process of formation because of growth of vegetation and the work of running water. It is supposed that these phenomena are closely related to solifluction or soil creep of the Wisconsin (Wtirm) periglacial environment.