【摘要】 尖峰岭复式岩基主要由尖峰岭超单元的中粗粒似斑状、细粒似斑状、粗中粒及细粒黑云母正长花岗岩组成。该超单元富硅、富钾、弱过铝一准铝质,碱度率较高,属碱性系列。总体上富含 Rb、Cs、Th、U、Pb、Zr、Hf、Y 等微量元素,强烈亏损Ba、Sr、P、Ti 和适度亏损Nb、Ta。轻重稀土分异较明显,（La/Yb）_N=8 29～30.36;中等—强烈亏损 Eu,δEu=0.43～0.05;早期单元稀土元素含量高而晚期单元明显降低。(⁸⁷Sr/⁸⁶Sr)_i和 T_2DM较高,分别为0.71658～0.71703和1639～1709Ma;而ε_Nd（t）值较低,为-7.59～-8.46。锆石 SHRIMP U-Pb 法获得其结晶年龄为249±5Ma。尖峰岭超单元的成因类型介于 S 型和铝质A型花岗岩之间,并且类似于高热（HHP）花岗岩,是在早三叠世后造山环境岩石圈拆沉、热软流圈上涌的动力学机制下,地壳变杂砂岩或变砂屑岩受到幔源流体富集后发生部分熔融的产物。熔融温度大约为770～790℃,压力约（10～12.5）×10⁸Pa（相当于深约34～42km）。熔体侵位后发生过较强的结晶分异作用。岩体内部降温至约300℃的时代（221～209Ma）与其外接触带上抱伦金矿的成矿时代（220～200Ma）相一致,比岩体结晶年龄晚了约30～40Ma。岩体内部长期保持中高温环境,有利于形成热水溶液对流循环系统而成矿。但该岩体主要是为金成矿作用提供了热动力,而不是主要提供了热液流体和矿质,因此,将抱伦金矿称为"与高热花岗岩伴生的热液型矿床"更恰当。更多还原

【Abstract】 The Jianfengliug composite hatholith is chiefly composed of the Jianfengling superunit with medium-coarse grained porphyritic,fine-grained porphyritic,coarse-medium grained and fine-grained biotite syenogranites.These rocks are weakly perahuninous-metaluminous,with high alkalinity ratios （AR） and belonging to the alkaline series.In general they are enriched in Si, K,Rb,Cs,Th,U,Pb,Zr,Hf,Y,strongly depleted in Ba,Sr,P,Ti and moderately depleted in Nb,Ta.The early unit has high REE contents and the later units have distinctly low REE contents.It displays remarkable differentiation between LREE and HREE, with （La/Yb）_M=8.29～30.36,medium to strong depletion of Eu （δEu=0.43～0.05）,high (⁸⁷Sr/⁸⁶Sr)_i values （0.71658～ 0.71703）,moderately old Nd model ages (T_2DM=1639～1709Ma),and moderately low ε_ND（t） values （-7.59～-8.46）.A zircon SHRIMP U-Pb dating yields a crystallization age of 249±5Ma for the Jianfengling superunit.This study indicates that the Jianfengling superunit,which belongs to a genesis type between S-type and aluminous A-type granite,and is similar to high heat production （HHP） granite,was produced at a temperature of 770～790℃ and a pressure of （10～12.5） 10⁸Pa （corresponding to a depth of 34～42km） by partial melting of crust metagreywackes or metapsammites enriched by mantle-derived fluid,which was in turn caused by Early Triassic lithospheric delamination and upwelling of a hot asthenosphere under a post-orogenic environment The intrusive melts experienced strong crystallization ffactiouation.The age when temperature of the middle of the batholith fell at about 300℃ is 221～ 209Ma,which is close to the mineralization age （220～200Ma） of the Baolun Au deposit located in exocontact of the batholith,and is about 30～40Ma latter than the crystallization age.This long-lived high-medium temperature setting was very helpful to the formation of hydrothermal convective circulation system that result in ore formation.But the granite was mainly acted as a source of heat energy for the metallogenesis of Au,rather than directly providing fluid and ore-forming materials.Therefore,we suggest to classify the Baolum gold deposit as"hydrothermal deposit associated with HHP granite"更多还原