College of Earth Sciences, Jilin University, Changchun 130026, China

Qingchengzi ore concentration area in Liao-Ji rift is an important lead-zinc ore area of China, and the deep prospecting in this area has great prospects. Based on the spatial occurrence of ore bodies the Pb-Zn deposit can be divided into three types: layered, vein-shaped and pinnate. The deep geological conditions in this area are deduced by analyzing the tectonic evolution process and rock mass gravity inversion. The tectonic evolution of Liao-Ji rift can be divided into three stages: Paleoproterozoic extension period, Mesoproterozoic compression period and Mesozoic reactivation period. The magmatic activities in the Indosinian epoch led to the distribution pattern of the present deposits. According to the gravity inversion, Shuangdinggou- and Xinling rock masses on the north and south sides of the mining area are connected in the deep. The connected rock body might be distributed in the entire mining area. Xinling rock mass may be a branch extending from Shuangdinggou rock mass along the northeast trending fault, the connected rocks provide magmatic hydrothermal fluid for the final, folds and faults result in different types of ore body shapes.