通过秦岭西坝花岗岩体及邻区脉岩体的岩石学、地球化学研究 ,探讨了秦岭造山带中生代期间由全面碰撞转入陆内造山的深部动力学过程。研究表明 :西坝花岗岩体及花岗斑岩脉具类似于埃达克质岩高 Sr( Ba) ,低 Y和 Yb,以及高 Sr/Y,La/Yb,Eu异常微弱的地球化学特征 ,反映其形成于地壳厚度增大的地质背景 ;闪长玢岩脉代表地壳减薄背景的产物。它们的形成指示秦岭造山带印支晚期到燕山早期地壳增厚 ,嗣后发生下地壳拆沉的重要转换过程 Based on the petrological and geochemical studies of the granitic plutons in the Xiba area and the adjacent plutons in the Qinling Mountains, the deep kinetic process of intracontinental orogeny transition from full collision to intracontinental orogen during the Mesozoic in the Qinling Orogenic Belt was discussed. The results show that the veins of Xiba granite and granite porphyry are similar to the geochemical features of high Sr (Ba), low Y and Yb, and high and weak Sr / Y, La / Yb and Eu in the adakitic rocks. Reflecting the formation of the crust thickness increased geological background; diorite diorite crust thinning background of the product. Their formation indicates the important conversion process of the Lower Qinling orogenic belt to late Yanshanian crustal thickening in the late Indosinian, followed by the subsequent crustal delamination