2. Institute of Geological Survey of Jilin Province，Changchun 130061，China;

3. International Centre for Geoscience Research and Education in Northeast Asia，Jilin University，Changchun 130026，China;

4. State Key Laboratory of Nuclear Resources and Environment，East China Institute of Technology，Nanchang 330013，China

is adjacent to the Xing--Meng orogenic belt and eastern part of the north margin of North China plate． It is a medium-sized gold deposit discovered in ductile deformation zone in recent years． The host rock assemblage of the deposit

is composed of chlorite-quartz-biotite schist，hornblende-biotite-quartz schist，chlorite-epidote-actinolite schist and muscovite-biotite schist． It is a set of greenschist facies and amphibolite facies structural rock series superimposed with complex metamorphic deformation． The mineralization process of Songjianghe gold deposit consists of

three phases: quartz-pyrite stage ( Ⅰ) ，quartz-polymetallic sulfide stage ( Ⅱ) and quartz-carbonate stage ( Ⅲ) ．The ore-forming fluid is CO2 --H2O --NaCl system with medium temperature and low salinity． The immiscibility offluid is the main mechanism leading to the precipitation of ore-forming elements． The genetic type of the Songjianghe deposit belongs to mesothermal-hydrothermal alteration gold deposit． The mineralization age of the deposit is Late Jurassic，which was in the extensional environment after the subduction and compression of the paleo-pacific plate to the Eurasian plate．