Table 1. Geology of the research area.

Location	Geologic age		Stratigraphy	Mark	Geological features
Topsoil	Cenozoic Era	4th	Alluvium	Qa	Clay, Sand, Gravel
Unconformity
Under 30 m	Mesozoic era Cretaceous Period		Ulsan Formation	Kul	Purpleshale, Grayshale, Sandstone, Conglomerate
				Kuho	Hornfels