答“对秦岭奥长环斑花岗岩质疑”  

A Reply to " A Query on the So-called Rakapivi Granite in the Qinling Orogen"

作　　者：卢欣祥[1] 王晓霞[2] 肖庆辉[3] 尉向东 董有 

机构地区：[1]河南省地质调查院,郑州450007 [2]中国地质大学 [3]国土资源部信息中心,北京100037 [4]河南省地质科学研究所,郑州450053

出　　处：《地质论评》2003年第2期146-154,共9页Geological Review

基　　金：中国地质调查局中国花岗岩重大基础问题研究项目(编号 200113900018)

摘　　要：环斑花岗岩是一种特殊结构的花岗岩类,并且多数产在元古宙克拉通中。笔者曾报道了在秦岭造山带中发育有印支期具有环斑结构的花岗质岩石。“对秦岭奥长环斑花岗岩质疑”一文认为它们不是环斑花岗岩,并引用Ramo的图表来说明自己的观点。本文将从以下几方面进行讨论:秦岭环斑花岗岩的研究历史;环斑花岗岩的定义;世界上环斑花岗岩的成因类型;秦岭环斑花岗岩的副矿物及铁镁含量和环斑钾长石特征;秦岭环斑花岗岩与基性岩共存等。本文还论证了秦岭环斑花岗岩不同于元古宙非造山环斑花岗岩,而是一种造山型的环斑花岗岩,其形成于后造山环境,是挤压(造山)向拉张(稳定)转折时期的产物。最后对研究秦岭环斑花岗岩的几个理论问题进行了探讨。Rapakivi granite, a special kind of granite with rapakivi texture, mostly occurs in Proterozoic cratons. The authors reported Mesozoic granitoids with rapakivi texture occurring in the Qinling orogenic belt. The questioned paper, however, did not consider it as rapakivi granite, and showed his point by comparing this granitoid with typical rapakivi granites in the figures of Ramo (1996). This paper will reply to the questions in these aspects: 1) the research history of the rapakivi granites in Qinling; 2) definition of rapakivi granites; 3) genetic type of rapakivi granites; 4) characteristics of the association of the rapakivi granites and relative mafic rocks. Then the paper demonstrates that the Mesozoic rapakivi granites in Qinling are different from the Proterozoic anorogenic rapakivi granites, which were formed in an orogenic setting, i. e. , a tectonic transition setting from compressional to extensional, therefore may belong to a kind of orogenic-type rapakivi granites. This paper also makes theoretic discussions on the rapakivi granites.

关 键 词：环斑结构 环斑花岗岩 造山带 构造转折 双峰式岩浆 秦岭地区 元古宙 

分 类 号：P588.1[天文地球—岩石学]