Geochronology, geochemistry, and tectonic significance of the Shirenshan gneiss in the southern margin of the North China Block

IF 1.1 4区地球科学 Q3 GEOLOGY

Geologia Croatica Pub Date : 2019-12-17 DOI:10.4154/gc.2019.21

Jingya Wang, S. Ren, S. Dong, Longming Li, D. Jiang, Yong-hong Shi, Jiahao Li, Chuanzhong Song, Xu Hang, Zhenqiang Li, J. Ouyang

{"title":"Geochronology, geochemistry, and tectonic significance of the Shirenshan gneiss in the southern margin of the North China Block","authors":"Jingya Wang, S. Ren, S. Dong, Longming Li, D. Jiang, Yong-hong Shi, Jiahao Li, Chuanzhong Song, Xu Hang, Zhenqiang Li, J. Ouyang","doi":"10.4154/gc.2019.21","DOIUrl":null,"url":null,"abstract":"The Shirenshan Block is a complex geological body located in the southern margin of the North China Block (NCB). From south to north, it can be divided into the Taihua Group migmatite, and the Shirenshan gneiss and magmatic rocks. The petrographic features, tectonic setting, provenance, and geological age of the Shirenshan gneiss using comprehensive field investigations, microstructural analysis, zircon U-Pb radioactive dating, and geochemical analyses were investigated for this study. The petrology, geochemistry, and geochronology of the Shirenshan gneiss suggests that it is mainly a felsic rock and its protolith was a high-K calc-alkaline series A-type granite. The protolith is high in SiO2, Al2O3, K2O, Na2O, and low in CaO and MgO. Overall, the Sr-Nd isotope composition of the samples showed no significant difference, indicating that the Taihua Group migmatite and the Shirenshan gneiss have the same source material. The Shirenshan block may be partially melted from the Taihua group and formed during activity of the Luo-Luan Fault. By the method of zircon dating analysis, the protolith age of the Shirenshan block was determined as 1559±16Ma (Early Proterozoic). Then, the crystallization age of the syntectonic migmatite is 439.2±7.6Ma, which was formed by subduction of the Taihua Group. During the early Cretaceous (119.5±1.3Ma), the Shirenshan gneiss may have experienced regional migmatization and formed the zircon rims age of the Yanshanian period. Litho-geochemical features of the Shirenshan block are similar to A1-type granites indicating that they are post-orogenic. Therefore, the metamorphic deformation of the Shirenshan gneiss reflects the tectonics in the southern margin of the NCB.","PeriodicalId":55108,"journal":{"name":"Geologia Croatica","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2019-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geologia Croatica","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.4154/gc.2019.21","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

The Shirenshan Block is a complex geological body located in the southern margin of the North China Block (NCB). From south to north, it can be divided into the Taihua Group migmatite, and the Shirenshan gneiss and magmatic rocks. The petrographic features, tectonic setting, provenance, and geological age of the Shirenshan gneiss using comprehensive field investigations, microstructural analysis, zircon U-Pb radioactive dating, and geochemical analyses were investigated for this study. The petrology, geochemistry, and geochronology of the Shirenshan gneiss suggests that it is mainly a felsic rock and its protolith was a high-K calc-alkaline series A-type granite. The protolith is high in SiO2, Al2O3, K2O, Na2O, and low in CaO and MgO. Overall, the Sr-Nd isotope composition of the samples showed no significant difference, indicating that the Taihua Group migmatite and the Shirenshan gneiss have the same source material. The Shirenshan block may be partially melted from the Taihua group and formed during activity of the Luo-Luan Fault. By the method of zircon dating analysis, the protolith age of the Shirenshan block was determined as 1559±16Ma (Early Proterozoic). Then, the crystallization age of the syntectonic migmatite is 439.2±7.6Ma, which was formed by subduction of the Taihua Group. During the early Cretaceous (119.5±1.3Ma), the Shirenshan gneiss may have experienced regional migmatization and formed the zircon rims age of the Yanshanian period. Litho-geochemical features of the Shirenshan block are similar to A1-type granites indicating that they are post-orogenic. Therefore, the metamorphic deformation of the Shirenshan gneiss reflects the tectonics in the southern margin of the NCB.

查看原文本刊更多论文

华北地块南缘石人山片麻岩的时代、地球化学及构造意义

石人山地块是位于华北地块南缘的一个复杂地质体。从南向北可分为太华群混合岩、石人山片麻岩和岩浆岩。通过综合野外调查、微观结构分析、锆石U-Pb放射性测年和地球化学分析，对石人山片麻岩的岩相特征、构造背景、物源和地质年龄进行了研究。石人山片麻岩的岩石学、地球化学和地质年代表明，它主要为长英质岩石，原岩为高钾钙碱性系列a型花岗岩。原岩中SiO2、Al2O3、K2O、Na2O含量高，CaO和MgO含量低。总体而言，样品的Sr-Nd同位素组成没有显著差异，表明泰华群混合岩和石人山片麻岩具有相同的源物质。石人山断块可能是由太化群部分熔融而成，形成于罗滦断裂活动期。通过锆石测年分析，确定了石人山地块的原岩年龄为1559±16Ma（早元古代）。同构造混合岩的结晶年龄为439.2±7.6Ma，是由太华群俯冲形成的。在白垩纪早期（119.5±1.3Ma），石人山片麻岩可能经历了区域混合岩化作用，形成了燕山期的锆石边缘时代。石人山地块的岩石地球化学特征与A1型花岗岩相似，表明它们属于后造山期。因此，石人山片麻岩的变质变形反映了NCB南缘的构造。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Geologia Croatica GEOSCIENCES, MULTIDISCIPLINARY-

CiteScore

2.90

自引率

23.10%

发文量

审稿时长

>12 weeks

期刊介绍： Geologia Croatica welcomes original scientific papers dealing with diverse aspects of geology and geological engineering, the history of the Earth, and the physical changes that the Earth has undergone or it is undergoing. The Journal covers a wide spectrum of geology disciplines (palaeontology, stratigraphy, mineralogy, sedimentology, petrology, geochemistry, structural geology, karstology, hydrogeology and engineering geology) including pedogenesis, petroleum geology and environmental geology. Papers especially concerning the Pannonian Basin, Dinarides, the Adriatic/Mediterranean region, as well as notes and reviews interesting to a wider audience (e.g. review papers, book reviews, and notes) are welcome.