中文摘要：

川西北地区位于松潘-甘孜造山带北部,产出众多的中生代花岗岩和卡林型金矿,金成矿作用与区域构造运动和岩浆活动有密切的内在联系。本文拟从花岗岩的角度分析这种内在联系,故测定了川西北的羊拱海黑云母二长花岗岩、达盖寨黑云母二长花岗岩和可尔因二云母二长花岗岩的黑云母或白云母Ar-Ar年龄,分别得到坪年龄158.7±1.4Ma、185.2±1.4Ma和157.6±1.2Ma,并参考积累的川西北花岗岩体的年代学数据,绘制了造山带北部、中部、东缘中部几个主要花岗岩体的冷却轨迹。不同构造位置花岗岩体的冷却轨迹表明,从造山带北部到造山带东缘中部,各花岗岩体的侵位年龄依次变新,冷却速率依次变缓,在区域构造运动相对较弱期间,各花岗岩的冷却速率明显降低。由以上特征,本文推断在中生代陆内造山过程中,构造应力自松潘-甘孜造山带北部向造山带东缘中部传递,各区域先后由造山相对活跃期进入造山相对宁静期。在造山宁静期,构造运动较弱,花岗岩体缓慢冷却,地壳的低温状态保持较长时间,利于金的成矿作用。因而,川西北的金矿主要形成于区域花岗岩的缓慢冷却阶段,这可能是金矿与花岗岩时空耦合的原因之一。

英文摘要：

Located at north of the Songpan-Garz orogenic zone, northwestern Sichuan hosts a great number of Mesozoic granite bodies and Carlin-type gold deposits. The gold mineralization has an internal relation with the tectonic movement and magmatism. Aiming at the problem, this study analyzed ages of biotite and muscovite from the Yanggonghai monzonitic granite, Dagaizhai monzonitic granite and Ke＇eryin two-mica granite using Ar-Ar dating method and yielded the plateau ages of 158.7± 1.4Ma, 185. 2±1.4Ma and 157.6±1.2Ma, respectively. Combined with these Ar-Ar ages and the ages by other isotope systems, the cooling tracks of major granite bodies in different locations have been drawn. The result show that from the northern orogenic zone to the center of eastern orogenic zone, the emplacement age of granites become young and cooling rates decrease; but at the relatively stable stage of orogenic process the cooling rates decrease distinctly. Based on the characteristics above, it can be concluded that during the Mesozoic orogenic process, the tectonic stress transferred gradually from the northern part of Songpan-garz orogenic zone to center of the eastern margin of the zone. All the tectonic units came in succession into a relatively pediocratic stage of the orogenic process. During the pediocratic stage, tectonic movement was slow, the cooling rate of granite bodies was low, and the crust maintained low temperatures for long time, and these are favorable for gold mineralization. Thus, gold deposits in northwestern Sichuan formed mainly during the slow cooling stage of regional granite, and it might spatially and temporally be one reason of the coupling relation between granite and gold deposits.