The Haoping and Jinshanmiao granitic plutons occurred in the southern margin of the North China Craton, are the important components of the Huashan complex batholith in Xiong' ershan region. Zircon LA-ICP-MS U-Pb dating yields ages of 128.7 +/- 1.0Ma to 129.3 +/- 2.4Ma for Haoping pluton, and of 127.6 +/- 1.6Ma for Jinshanmiao pluton, suggesting that they were all formed in Early Cretaceous. The Haoping pluton consists of alkali-feldspar, plagioclase, quartz, biotite and minor amphibole, and is mainly characterized by development of megaphyric alkali-feldspar, whereas the mineral assemblages of the Jinshanmiao pluton are alkali-feldspar, plagioclase, quartz and biotite. Chemically, these two plutons are both metaluminous, and characterized by rich in silicon and alkaline, poor in magnesium, and have high FeOT/(FeOT + MgO) ratios. These rocks are all enriched in Cs, Rb, Ba and Sr, etc., and depleted in Nb, Ta, Ti and Y, etc., and display a significant fractionation between LREEs and HREEs, with weakly negative Eu anomalies or no Eu anomalies (Eu/Eu* = 0.69 similar to 1.26). Therefore, the Haoping and Jinshanmiao plutons could be grouped into I-type granites, and the latter should be further categorized to the highly fractionated granites due to the higher degree of differentiation (D. I. = 96.6 similar to 97.3). The Lu-Hf isotopes shows that the epsilon(Hf)(t) values of the Haoping pluton range from -10.2 to -13.3, with t(DM2) ages between 1.8Ga and 2.0Ga, while the epsilon(Hf)(t) values of the Jinshanmiao range from -13.3 to -17.5, with the t(DM2) ages of 2.0Ga to 2.2Ga, indicating that these two plutons might be derived from the ancient materials of Taihua Group basement which was reformed by the mantle or the juvenile crust during the long-time geological evolvement. Integration of regional geology, whole-rock geochemistry and geodynamic considerations suggests that the Haoping and Jinshanmiao plutons should be emplaced in the intracontinental extensional environment followed by the end of the collision between the Yangtze and the North China blocks, which implies that they were formed during the tectonic transition from the Paleo-Tethys subduction-collision system to the Paleo-Pacific regime. During this diagenetic process, large amount of hydrothermal fluids with abundant volatile components (e. g., F, Cl) derived from the Haoping and Jinshanmiao magmatic systems, extracted and gathered the metallogenic materials from the country rocks, or superimposed and reformed the preexisting (Indosinian or Early Yanshanian) gold deposits, and then transported them to the intersection of many tectonic systems and formed large scale mineralization.
