The site is located in an “U” type small plain with north gentle dip and its east side, south side and
west side are hills with altitude between ten to dozens of meter while the north side is a river. The
geologic section from bottom to top in the study area is: (1) Upper Cretaceous Pukou group with general
depths below 40-50 meters and purplish-red or gray-yellow sandy conglomerate.