胶西北大尹格庄金矿床与夏甸金矿床差异性研究

Difference study on Dayingezhuang Gold Deposit and Xiadian Gold Deposit,northwest Jiaodong

大尹格庄金矿床和夏甸金矿床均分布于招平断裂中段,但二者在赋矿围岩岩性与化学成分、矿石特征、蚀变岩与蚀变矿物特征等方面存在显著差异。与夏甸金矿床相比,大尹格庄金矿床的招平断裂主裂面断层泥颜色浅,厚度小;玲珑型花岗岩含SiO_(2)、K_(2)O相对较低,含Al_(2)O_(3)、CaO、MgO、TFe_(2)O_(3)相对较高,且少见变质岩残留体;红化蚀变规模和强度较高;金矿化主要产于蚀变的玲珑型花岗岩围岩中,属典型蚀变岩型金矿床,矿石银含量较高,且常见菱铁矿。与大尹格庄金矿床相比,夏甸金矿床的招平断裂主裂面断层泥颜色黑,厚度大;矿体上盘变质岩中见有大理岩夹层;玲珑型花岗岩中常见变质岩残留体;暗灰色矿石中保留有变片麻状构造和变条带状构造,空间和成因上与变质岩关系密切,常见磁黄铁矿化;蚀变岩中见含钨金红石及白钨矿化,局部还见有石英脉型金矿化;黄铁绢英岩中SiO_(2)、Al_(2)O_(3)含量较低,K_(2)O、Na_(2)O、CaO、MgO含量较高,红化蚀变花岗岩中K_(2)O含量低于新鲜玲珑型花岗岩。赋矿围岩岩性差异及对成矿的制约是导致大尹格庄金矿床与夏甸金矿床差异性的关键。根据电化学成矿机制,夏甸金矿床成矿元素主要来自矿体上盘变质岩围岩,而大尹格庄金矿床成矿元素主要有2种来源,即胶东群变质岩和玲珑型花岗岩。

Both Dayingezhuang and Xiadian gold deposits are located in the middle part of the Zhaoping fault.There are significant differences in ore-hosting wall rock lithology,chemical composition,ore features,characteristics of altered rocks,and altered minerals between the two deposits.Compared to Xiadian Gold Deposit,the fault slime color is light and the thickness is thin in the main fracture face of the Zhaoping fault in Dayingezhuang Gold Deposit;the content of SiO_(2)and K_(2)O in Linglong granite is lower,and the content of Al_(2)O_(3),CaO,MgO,TFe_(2)O_(3)is higher,besides,metamorphic rock remains are rarely seen;the scale and intensity of reddenization alteration are stronger;gold mineralization mainly occurs in the altered Linglong granite wall rocks,the deposit is typically altered rock type gold deposit with high silver content in the ore and often seen siderite.Compared to Dayingezhuang Gold Deposit,in Xiadian Gold Deposit,the fault slime color is black and the thickness is great in the main fracture face of the Zhaoping fault;there is a marble interlayer in the hanging wall metamorphic rocks of the ore body;metamorphic rock remains are commonly seen in Linglong granite;metamorphic gneissic structure and metamorphic banded structure were reserved in the dark grey ore,which had a close spatial and genetic relationship with the metamorphic rocks,plus,pyrrhotite can often be seen in the ore;scheelite and tungsten-bearing rutile can be seen in the altered rocks,the quartz vein type ore can be seen in local areas;the content of SiO_(2),Al_(2)O_(3)in beresite is lower and the content of K_(2)O,Na_(2)O,CaO,MgO is higher,the content of K_(2)O in the reddenization altered granite is lower than fresh Linglong type granite.The lithological difference of ore-hosting wall rocks and the restrictions to mineralization are the key factors that differentiate between Dayingezhuang and Xiadian gold deposits.According to the electrochemical metallogenic mechanism,the ore-forming elements of Xiadian Gold Deposit are mainly derived from the metamorphic wall rocks in the upper wall of ore bodies,while the ore-forming elements of Dayingezhuang Gold Deposit are derived from 2 sources,that is Jiaodong Group meta-morphic rocks and Linglong granite.