淮河流域地层可分为华北、扬子、秦岭三个一级地层区,沿六安—信阳—确山—栾州一线以北为华北地层区,以南为秦岭地层区。流域东南部为扬子地层区。流域东南部为扬子地层区,南部以郯庐断裂为界,沿洪泽湖—泗阳—连云港一线向东北延伸,西北 The Huaihe River Basin strata can be divided into three first-grade stratigraphic zones in North China, Yangtze River and Qinling Mountains. The north of the Lu’an-Xinyang-Queshan-Luanzhou line is the North China stratum and the south is the Qinling stratigraphic zone. Southeast basin basin for the Yangtze strata. The southeastern part of the basin is the Yangtze stratigraphic zone, which is bounded by the Tanlu fault in the south and extends northeastward along the line of Hongzehu-Siyang-Lianyungang. The northwest