Geological Characteristics Of Lianzigou Gold Deposit In Western Xiaoqinling Of Luonan County, Shaanxi Province

The working area is located in the west of Xiaoqinling gold ore deposit,Western Henan Uplift,southern margin of the North China platform. The outcrops in this area are mainly Qincanggou formation of Archean Taihua Group and the Gaoshanhe formation of Mesoproterozoic,there is an Angular unconformity between the Qincanggou formation and the upper stratum Gaoshanhe formation.The working area is in the south limb of Dayueping-Jinluoban anticlinorium, which is a monoclinal structure.The gneissic schistosity of Qincanggou formation, Archean Taihua Group has a strike of northwestwards,and the dip is NNE-NE,the Gaoshanhe formation in the south has a strike of southeastwards.There is a northeastwards fault in this area,and the orebody of Lianzigou deposit is hosted in this fault.There is no outcrops of magmatic rocks in this area,but there are vein rocks like Diabase, Syenite Porphyry and Potash Feldspar Pegmatite.The 9 Mineralization alteration zones found in the working area have basiclly consistent occurrence with the northeastwards fault structure.They are parallel distributed in the space domain and all of them host gold orebody.7 industrial orebody have been diclineated through the geological prospecting,they are named gold orebody Ⅲ-1、Ⅱ-2、Ⅱ-1、Ⅴ、Ⅳ、Ⅵ、Ⅺ.Each of orebody Ⅲ-1 and Ⅱ-2 has a large scale and they are the main industrial orebody. The orebodies are relatively simple,assumed veinlike,lenticular and veinlike resembles forms.The scale ranging in size,the length is ranging from 55 metres to 550 metres,and the thickness ranging from 1.4 metres to 1.6 metres,the grade of orebodies ranging from 1.6 g/t to 2.8g/t.The types of wall rock alteration are mainly Silicification,Sericitization,Pyritization,Lead mineralization,Potassium Carbonate and Chlorite.The ore minerals are mainly pyrite, followed by Galena,Tetrahedrite and Altaite,and the gangue minerals are mainly Quartz, Feldspar and Calcite.The precious metal mineral is natural gold.And the gold mainly exists in the form of intergranular gold,inclusion gold and fissure gold.The main ore texture are granular texture and crushing texture.The ore structures are mainly fragmentation, block and disseminated structure.The nature types of ore are altered rock type and quartz vein type.