College of Earth Sciences��Jilin University��Changchun 130061��China

Heerwusu Pb-Zn deposit is located in the Shaolang river lead- zinc metallogenic belt of Wengniute banner��on the north side of Xar Moron ��iver in Inner Mongolia�� The intrusive rocks exposed in the studied area are main monzogranite and diorite porphyrite�� Orebodies are obviously controlled by fracture structures��belonging to the hydrothermal vein type lead- zinc deposit�� Mineralization is divided into two stages: early replacement stage and late fracture filling stage�� The study of fluid inclusion indicates that in the quartz veins mainly developed gas- liquid two phase inclusions�� From early stage to late stage��the temperature��salinity and pressure of the metallo- genic fluid gradually reduced��with characteristics of low temperature (170�� �� 316��) and low salinity (1. 2 �� 3. 7%NaCleqv) and metallogenic pressure for 11. 83 ��24. 30 MPa�� Stable isotopes (carbon��hydrogen��oxygen) evidenced that the ore- forming fluid is magmatic water and meteoric water mixing the fluid��which involved in the mineralization characteristics�� Combined with the regional setting��ore- forming materials for deep magma in the pe- riod of tectonic activity activated again��and the lower crust with the ore bearing rock occurred partial melting of mineralizing fluids��and concentrated in favorable positions of the fracture structures in mineralization�� The Heer- wusu lead- zinc deposit is a medium- low temperature hydrothermal vein type deposit��