전남 고흥 일대 백악기 화강암류의 아문미세균열을 이용한 백악기 말-신생대 3기 초 고응력장

Abstract

Late Cretaceous to early Tertiary paleostress was evaluated by analyzing the healed microcracks in the Cretaceous granite of the Goheung area, south Korea. Healed microcracks in five granite samples (GH-1, GH-3, GH-4, GH-5, GH-8) were investigated and measured according to direction. The directions of maximum horizontal principal stress in GH-1, GH-3, and GH-4 are dominantly , while minor directions are N-S and . In GH-5 and GH-8, are the most dominant directions, while is the minor direction. Thus overall, the most dominant directions of healed microcracks in the study area are oriented , while minor directions are oriented , essentially NE. Combining the paleostress results of this study with other studies, the direction of the maximum horizontal principal stress in the study area during the late Cretaceous to the early Tertiary should perhaps be changed WNW to NE. The reason for this is thought to be the complex tectonic movements which occurred in northeast Asia at that time.