论文部分内容阅读
本文介绍了新近在北秦岭造山带中发现的高压─超高压变质带（北带）和松树沟高压变质带（南带）代表性变质岩的化学成分、微量元素和稀土元素特征．这些高压、超高压变质岩的原岩多为基性火成岩。与北带相比，南带的高压变质岩起源于更强烈亏损的地幔，结合岩相学，同位素年龄和Ｓｍ－Ｎｄ同位素特征的差异，推测南北二带形成于不同的地质事件。产在北秦岭造山带中的高压─超高压变质岩的地球化学特征与东部产在南秦岭造山带的同类岩石有许多相似之处．推测秦岭─大别造山带从南到北是在同一个岩石圈上演化来的，不是不同地块拼接成的。
In this paper, the chemical composition, trace elements and rare earth elements of the representative metamorphic rocks found in the North Qinling orogenic belt and the Songhuagou high-pressure metamorphic belt (the northern belt) are introduced. The protoliths of these high-pressure and ultrahigh-pressure metamorphic rocks are mostly basic igneous rocks. Compared with the northern belt, the high-pressure metamorphic rocks in the southern belt originated from a more drastic loss of the mantle. Based on the petrographic, isotopic ages and Sm-Nd isotopic characteristics, it is speculated that the northern and southern belts formed in different geological events. The geochemical characteristics of the HP-UHP metamorphic rocks in the North Qinling orogenic belt have many similarities with the similar rocks in the eastern Qinling orogen. It is speculated that the Qinling-Dabie orogen evolved from the south to the north over the same lithosphere, not from different plots.