华北克拉通北缘西拉沐沦钼多金属成矿带钼矿化类型、特征及地球动力学背景

最近，在华北克拉通北缘，沿东西走向的西拉沐沦构造带两侧异军突起地出现了一个400多千米长、300千米宽的钼矿带，短短4年时间已经发现了10余个大型-中型钼矿床，显示了巨大的资源前景。钼矿床的空间分布受区域东西向、北东向及北西向断裂联合控制，钼矿床的形成与中生代的中酸性侵入体关系密切，矿床产于花岗岩体中、斑岩体内外接触带或附近，矿床类型以斑岩型、石英脉型、火山热液型及云英岩型为主。空间关系表明钼矿床的形成主要与中生代富硅、富钾酸性侵入岩有关。成矿年代学研究表明，西拉沐沦成矿带钼矿具有三期成矿作用：包括245Ma、150Ma和138Ma。其对应的成矿动力学背景为印支期华北板块与西伯利亚板块碰撞造山后伸展阶段和燕山期中国东部构造大转折期。其中，印支期的成矿作用和相应的岩浆活动在以往的工作中较少论及。

Mineralizing types, geological characteristics and geodynamic background of molybdenum deposits in Xilamulun molybdenum polymetal metallogenic belt on northern margin of North China Craton

Recently, a new molybdenum metallogenic belt was discovered along Xilamulun geosuture zone on northern margin of North China Craton. It spans 400km in length and 300km in width. More than 10 Mo deposits of large-middle scale were discovered during the last 4 years. The Mo deposits of this belt are controlled jointly by EW-, NE- and NW-trending faults, and are associated with acid granites in time and space. The Mo deposits are usually distributed in granite body, along the endo- or exo-contact zones of the granite porphyry, or nearby. The Mo deposits can be classified into four types: porphyry, quartz vein, volcanic hydrothermal and greisen type. The relationship between the Mo deposits and intrusives shows that the Mo deposits are associated with Si- and K-rich intrusive. Based on the metallogenic chronology, the authors suggested that there existed three main stages of Mo mineralization (245Ma, 150Ma and 138Ma respectively) in the Xilamulun metallogenic belt. The corresponding geodynamic background covers the post-collisional extension of the newly-amalgamated North China-Siberian plates during Indo-Chinese epoch, to the transition of tectonic regimes and lithospheric thinning in eastern China.