研究表明,川西北雪宝顶矿床的白云母40↑Ar/39↑Ar坪年龄为(189.9±1.8)Ma,说明雪宝顶矿床形成于印支晚期—燕山早期,是三叠纪华北板块与扬子板块碰撞的产物。文章通过雪宝顶矿床与甲基卡、可尔因和丹巴等伟晶岩型矿床的时空位置对比,并依据伟晶岩对大陆活动的示踪作用,推测中生代松潘-甘孜造山带的演化过程为:华北陆块、羌塘-昌都陆块分别与扬子陆块碰撞后,构造应力自北向南、自西向东逐步向松潘-甘孜地块的中心传递,雪宝顶、甲基卡、可尔因地区相继进入相对稳定发展阶段,构造应力最后在丹巴地区汇聚,形成丹巴白云母矿床。
The Xuebaoding W-Sn-Be deposit is located in the Motianling tectonic zone of Songpan-Ganzi orogenic belt. The muscovites dated were sampled from scheelite veins. The 40↑Ar/39↑Ar plateau age of muscovites is (189.9± 1.8) Ma, which shows that the Xuebaoding deposit was formed in Late Indosinian and Early Yanshanian periods. Thus, the Xuebaoding deposit and some gold deposits in the Qinling orogenic belt might have resulted from the collision of the North China Block and the Yangtze Block. In Songpan-Ganzi orogenic belt, besides the Xuebaoding deposit, there exist some pegmatite type deposits, such as the Jiajika rare metal deposit, the Ke' eryin rare metal deposit and the Danba muscovite deposit. On such a basis, the evolution of the Songpan-Ganzi orogenic belt in Mesozoic can be described as follows: in the late stage of Indosinian epoch, the North China Block and the Qiangtang-Changdu Block collided with the Yangtze Block respectively, and tectonic stress was transferred from border to interior gradually in the NS and WE directions. Under such a tectonic background, Xue-baoding area, Jiajika area, Ke' eryin area, and Danba area entered into the phase of stabilization one after another and, finally, the stress was converged in Danba area.