The granites in Xinchenggou area of Dongning County are located on the active continental margin of eastern part of Xing'anling-Mongolian orogenic belt. In this paper, petrologic and element geochemical studies were carried out for granites in Xinchenggou area, Dongning County. Major element geochemistry shows that the rocks are calc-alkaline and I-type granites, and are also characterized by enrichment of alkali, relative enrichment of potassium and S-type syn-collisional granites. The Rittman index δ is from 1.41 to 2.11. The alumina saturation index ACNK is from 1.02 to 1.20. REE concentrations are low ( ΣREE=72.35×10 -6~217.64×10 -6 ) and show obvious differentiation between LREE and HREE ( LaN/YbN=2.74~11.37 ), with apparent Eu negative anomalies ( δEu=0.14~0.83 ), and the abnormality of δCe (δCe =0.96~1.11) is not apparent. In addition, the rock mass is relatively poor in such elements as Nb, Ta, P and Ti, and rich in Rb, Ba and K . w(Nb)/w(Ta) ratios of trace elements are less than 16.2, suggesting that the magmas were formed by partial melting of the crust. The magmas were formed by collision between the North China plate and Siberia plate in Late Paleozoic-Early Mesozoic period and subduction of the paleo-Pacific plate towards the east edge of Eurasia in Late Triassic. The magmas also had the characteristics of multi-stages and complex genesis. Geophysical and geochemical anomaly, geochemical characteristics, and geochemical ore parameters indicate that this area has prospecting potential for epithermal-type Au-Ag-Cu deposits.
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