Abstract:The Hulalin gold deposit in the Upper Heilongjiang Basin is located in the northern margin of the Erguna micro- block in the northern Daxinganling, east of the Xingmeng orogenic belt, and is clamped between the Mongolian Okhotsk suture zone and the Deerbugan fault. The body mainly exists in the cryptoexplosive breccia, which is closely related to the granite porphyry and quartz porphyry formed by the Early Cretaceous magmatism.In this paper, the LA- ICP- MS zircon U- Pb dating method was used to obtain the crystallization age of granite porphyry rock mass were 141.7±1.1 Ma (MSWD=0.086), quartz porphyry rock mass (2 pieces) were 144.86±0.56 Ma (MSWD=0.580) and 142.6±0.74 Ma (MSWD=0.077), both of which are products of early Cretaceous magma activity. The zircon εHf(t) of granite porphyry and quartz porphyry are -4.14~0.16, -2.25~1.37, and most of the data is below the chondrite line.The Two- stage model ages (tDM2) of this two kinds of rock masss are 987.08 ~1259.04 Ma,908.38~1138.56 Ma.The geochemical characteristics of the rock show that the granite porphyry w(SiO2) is 66.21%~66.70%, w(Al2O3) is 15.18%~15.45%, w(Na2O + K2O) is 7.56%~8.17%, aluminum saturation index A/CNK is 1.03~1.06, showing weak aluminum high potassium calc- alkaline- potassium rock sequence.Quartz porphyry w(SiO2) is 66.34%~68.25%, w(Al2O3) is 13.77%~15.05%, w(Na2O+K2O) is 6.76%~9.06%. In the SiO2- K2O diagram, it falls into the sequence of potassium basalt. The REE of granite porphyry and quartz porphyry are 71.07×10-6~97.92×10-6, 135.53×10-6~156.15×10-6 respectively, and (La/Yb)N is 24.87~26.81, 31.33~40.62 respectively, all of which show the relative enrichment of light rare earth (LREE) and the right declination of heavy rare earth (HREE), and the light and heavy rare earth fractionation is obvious.The δEu is 0.65~0.88 and 0.41~0.50 respectively. The latter is more abnormal than the former.Both rock masses are relatively rich in incompatible elements such as Rb, K and other large ion lithophile elements (LILEs), LREE and U, and strongly deplete Nb, Ta, Ti, P and other high field strength elements (HFSEs). The rock genetic type discriminant map shows that the Early Cretaceous intrusive rocks of the Hulalin in the Upper Heilongjiang Basin are I- type granites, which are formed in the Mongolia- China and North Korea continent and the Siberian continent, colliding with the Late collision environment, from the extrusion to the extension of the tectonic setting. It may be a product of thickening of the crust during the ancient land- continent collision of the Mongolia- Okhotsk orogenic belt, partial melting, and by mantle source material or new crust melting mixed contamination products. This further restricted the Mongolian- Okhotsk ocean from being completely closed until at least 144.9 Ma.