同源花岗岩谱系填图——内蒙古二连宝德尔石林花岗岩填图试点

发布时间：2018-07-03 20:14

本文选题：同源花岗岩 + 谱系填图　；参考：《地质通报》2017年11期

【摘要】：单元-超单元花岗岩谱系填图方法是以同源岩浆演化理论为指导思想建立发展的。该方法从20世纪80年代开始在中国推广和应用,然而,随着岩浆岩理论的不断发展及填图实践过程中遇到的问题,填图方法回归到早期的"岩性+时代"方法。在新的形势下,如何开展好新一轮的花岗岩填图工作,谱系填图是否仍具有适用性值得分析探讨。以中蒙边境地区出露的宝德尔石林花岗岩体填图试点成果为例,阐述岩浆岩填图试点方法的可行性。填图结果显示,该岩体为复式杂岩体,发育约160Ma和140~124Ma两期二长花岗岩,这两期二长花岗岩时代和岩石结构存在差别,野外的主要区别在于粒度。它们处于同一个区域性伸展背景,属于同源岩浆演化的产物。依据谱系划分方案,可以划分为晚侏罗世和早白垩世2个序列及5个单元,且可以进行区域对比。因此,基于岩浆演化规律,以解体岩体和进行岩石类型归并为精髓的谱系填图对于同源花岗岩仍是适用和必须的,但不可扩大化。
[Abstract]:The method of unit-superunit granite pedigree mapping is based on the theory of homologous magma evolution. The method has been popularized and applied in China since 1980s. However, with the continuous development of magmatic rock theory and the problems encountered in mapping practice, the mapping method reverts to the early "lithologic age" method. Under the new situation, how to carry out a new round of granite mapping and whether the pedigree mapping is still applicable is worth analyzing and discussing. Taking the experimental results of Baodel Shilin granite body mapping in the border area of China and Mongolia as an example, the feasibility of the pilot mapping method of magmatic rock is expounded. The mapping results show that the rock body is a complex, which developed about 160 Ma and 140 ~ 124 Ma periods of monzogranites. The age and structure of these two periods are different, and the main difference in the field is the granularity. They are in the same regional extensional background and belong to the evolution of homologous magma. According to the pedigree division scheme, it can be divided into 2 sequences and 5 units of late Jurassic and early Cretaceous, and can be compared with each other. Therefore, based on the law of magmatic evolution, the pedigree mapping with the essence of disintegrated rock mass and rock type merging is still suitable and necessary for the homologous granite, but it cannot be expanded.
【作者单位】：中国地质科学院地质研究所;
【基金】：中国地质调查局项目《侵入岩1∶5万专题填图试点及新方法填图试点》(编号:21201102000150021-01)
【分类号】：P588.121;P623

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