五台幔枝构造的演化与金、银多金属矿床

Evolution of mantle-branch structures and gold-silver-polymetal deposits in Wutai region

五台-恒山花岗岩-绿岩地体与燕山地体(西侧部分)所分布的金、银多金属矿床,是受太古宙超大陆地壳裂解作用所形成的裂谷型热幔柱,和复合或叠加的中生代幔枝构造控制,均沿EW向及NE向韧性剪切带分布.在幔枝构造的内部是以金(铁多金属)矿床为主,其外围拆离带是以银多金属矿床为主,形成"金三角、银镶边"的特征.它们的成因皆和地幔活动导致的壳幔岩浆侵位有着内在联系.

There are numerous goldsilverpolymetal deposits in WutaiHengshan granitegreenstone terrane and in the region to the western boundary of Yanshan terrane.The emplacement of these deposits was initially constrained by a rifttype hot mantle plume associated with breakdown of the achaean supercontinent, while transformation and overprinting of them was caused by mesozoic mantle branches. These deposits are distributed along EW and NE-trending ductile shear zones. Areas above the mantle branches are dominated by gold(iron and polymetallic)deposits, whereas the surrounding areas are characterized by silver and polymetallic deposits, resulting in a configuration of silver selvage on a gold triangle.These deposits are genetically related to mantle activity and resultant crustal and mantle magmatism.