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秦岭是扬子板块和华北陆块间的复合造山带，其中存在两个古缝合带。北面的新元古代到早古生代商－丹缝合带介于北秦岭和南秦岭之间；南面的晚古生代勉－略缝合带形成于南秦岭与扬子陆块北缘之间，属于确知的扬子陆块内部打开形成的类型。北秦岭在地壳增生历史，元古宙上地幔性质，以及元古宙以来地幔相对富Ｎｂ、Ｔａ、Ｃｕ，高Ｒｂ／Ｓｒ、Ｂａ／Ｓｒ、Ｂａ／Ｌａ、Ｔｈ／Ｌａ、Ｎｂ／Ｔａ比值和相对贫Ｆｅ、Ｍｏ方面均与南秦岭和扬子陆块北缘一致，而与华北陆块南缘明显不同。变玄武岩类的Ｐｂ同位素三维空间拓扑图和εＮｄ（ｔ）－２０６Ｐｂ／２０４Ｐｂ图显示，区域一级地球化学界面位于北秦岭与华北陆块的分界处，二级界面才是商丹－缝合带。构造侵位于该带中的松树沟蛇绿岩（１０００Ｍａ±）中已发现并存着Ｎ－ＭＯＲＢ和Ｅ－ＭＯＲＢ型变拉斑玄武岩，表明它们的岩浆分别来自亏损地幔和深部地幔热柱源区。松树沟蛇绿岩与勉略蛇绿岩中的Ｎ－ＭＯＲＢ型岩石具有彼此相似的同位素组成和特征元素对比值，暗示松树沟蛇绿岩所代表的古洋壳也应属于扬子板块内部型。加之，新元古代之前秦岭只存在裂谷系而无板块结合带，故可确定北秦岭原来应属于扬子板块的组成部分。对秦岭群和宽坪群变拉斑玄武岩及?
Qinling Mountains is a composite orogenic belt between the Yangtze plate and the North China terrane. There are two ancient suture zones. The Neoproterozoic to early Paleozoic Shang-Dan suture zone lies between North Qinling and South Qinling; the late Paleozoic Mian-slightly suture zone formed in the south between the South Qinling and the northern margin of Yangtze block belongs to the well-known Yangtze The type of formation that is formed inside the land block. The North Qinling has been characterized by the crustal hyperplasia, the Proterozoic upper mantle, and the relatively rich mantle Nb, Ta, Cu, high Rb / Sr, Ba / Sr, Ba / La, Th / La and Nb / Ta ratios Relatively poor Fe and Mo are consistent with the northern margin of the South Qinling and the Yangtze block, but distinctly different from the southern margin of the North China block. The Pb isotope three-dimensional topological maps and εNd (t) -206Pb / 204Pb maps of the basaltic rocks show that the regional primary geochemical interface is located at the boundary between the North Qinling and North China terraces, and the secondary interface is the Shangdan-suture. N-MORB and E-MORB type of uplifted basalt have been found in the Songshugou ophiolite (1000Ma ±) intruded into the zone, suggesting that their magmas are derived from the depleted mantle and the deep mantle plume. The similar compositions and characteristic elements of N-MORB rocks in the Songshugou ophiolite and the Mianlue ophiolite show that the paleo-oceanic crust represented by the Songshugou ophiolite also belongs to the Yangtze plate interior . In addition, before the Neoproterozoic Qinling Ridge only exists without plate combination zone, it can be determined that the original part of the North Qinling Mountains should belong to the Yangtze plate. On the Qinling Group and Kuan Ping Group of threshing basalt and?