勉略康构造混杂岩带西段金矿床地质特征及成矿规律

Geological Characteristics and Metallogenic Regularity of Gold Deposits in the Western Part of Mianluekang Tectonic Melange Belt

勉略康构造混杂岩带是秦岭造山带和扬子板块构造缝合带的一个重要组成部分,是中央造山带中的贵金属重要成矿带,仅次于商丹构造带。通过分析略阳县吴家河金矿与金家河金矿地质特征、控矿因素,发现金赋矿层位为泥盆系金家河岩组中岩段千枚岩、上岩段乔子沟火山岩;矿体受控于韧性剪切带,其中近东西向剪切带控制着矿床的展布和规模,近南北向的叠加剪裂隙对金具有富集作用;主要有硅化、黄铁矿化等矿化蚀变与金形成密切相关;矿床成因类型是受控于韧性剪切带且与火山沉积碎屑岩相关的构造蚀变岩型金矿。

The Mianluekang tectonic melange belt is an important part of the Qinling orogenic belt and the Yangtze plate tectonic suture zone.It is an important metallogenic belt of precious metals in the central orogenic belt,second only to the Shangdan tectonic belt.By analyzing the geological characteristics and ore-controlling factors of Wujiahe gold deposit and Jinjiahe gold deposit in Lueyang County,it is found that the gold-bearing strata are phyllite in the middle rock section of Devonian Jinjiahe formation and Qiaozigou vol-canic rock in the upper rock section.The ore body is controlled by the ductile shear zone,in which the near-ly east-west shear zone controls the distribution and scale of the deposit,and the nearly north-south super-imposed shear fractures have enrichment effect on gold.There are mainly silicification,pyritization and oth-er mineralization alterations closely related to gold formation.The genetic type of the deposit is a tectonic al-tered rock type gold deposit controlled by ductile shear zone and related to volcanic sedimentary clastic rock.