盘龙江为流入滇池的最大河流,主河道长约100公里,流域面积为847平方公里,在滇池北东形成广阔的三角洲平原(图1)。根据钻孔揭示,该区北东第四纪沉积以三角洲平原沉积物为主,南西部分主要为湖泊沉积,其中夹7—20层泥炭与褐煤层,最多可达27层,并有油气显示。这套沉积物自北东向南西呈喇叭状展布,沉积物厚度亦随之从100米渐增至1000余米(图1)。与下伏古生代地层呈角度不整合接触,不整合面上有厚2—15米之红色 Panlong River is the largest river flowing into Dianchi Lake. The main river channel is about 100 kilometers long and the drainage area is 847 square kilometers. It forms a vast delta plain in the north east of Dianchi Lake (Figure 1). According to the boreholes, the Quaternary sediments in the northeastern part of the area are dominated by deltaic sediments and the southwestern part is mainly lacustrine sediments. Among them, there are 7-20 layers of peat and lignite with a maximum of 27 layers with oil and gas. The sediment flared from north-east to south-west, and the sediment thickness increased from 100m to 1000m (Figure 1). Unconformity with the underlying Paleozoic stratigraphic contact, the unconformity surface of 2-15 meters thick red