Petrogenesis of the Granitic Dykes in the Yangshan Gold Belt: Insights from Zircon U-Pb Chronology, Petrography, and In-Situ Hf Isotope Analysis
The Yangshan gold belt is renowned for its igneous rock formations, particularly dykes that form in tectonically weak zones. Some of these rock formations exhibit a close spatial relationship with gold mineralization, and a tiny portion of the granitic dykes serve as gold ore bodies by themselves. I...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-05-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/13/6/718 |
| _version_ | 1797593384631664640 |
|---|---|
| author | Zhonghu Yang Jianzhong Li Tao Xiong Yong Huang Ciren Lamu Yang Zhao Wei Wei |
| author_facet | Zhonghu Yang Jianzhong Li Tao Xiong Yong Huang Ciren Lamu Yang Zhao Wei Wei |
| author_sort | Zhonghu Yang |
| collection | DOAJ |
| description | The Yangshan gold belt is renowned for its igneous rock formations, particularly dykes that form in tectonically weak zones. Some of these rock formations exhibit a close spatial relationship with gold mineralization, and a tiny portion of the granitic dykes serve as gold ore bodies by themselves. In order to investigate the nature of granitic dykes and their association with gold mineralization, we conducted a comprehensive study consisting of zircon U-Pb chronology, petrography, and in situ Hf isotope analysis of 25 granitic dyke samples collected from east to west across the belt. According to LA-ICP-MS zircon U-Pb dating results, the granitic dykes inherited zircon ages that are concentrated between 745.0 and 802.0 Ma, and magmatic intrusion ages that mainly fall between 201.0 and 213 Ma. Moreover, the granitic dykes display a calc-alkaline to high-K calc-alkaline peraluminous series, which is relatively enriched in light over heavy REE, with moderate Eu anomalies. These dykes are rich in large-ion lithophile elements and poor in high-field-strength elements. The zircon Lu-Hf isotope data range from εHf(t) values of −1.5 to 0.1, mantle model (T<sub>DM</sub><sup>1</sup>) ages range from 859 to 937 Ma, and crustal model (T<sub>DM</sub><sup>2</sup>) ages range from 1111 to 1218 Ma. The granitic dykes found in the Yangshan gold belt were formed between 200 and 213 Ma ago, during a period of intracontinental extension following the late collision between the Yangtze plate and Qinling microplates. These dykes originated from the volcanic basement of the Mesoproterozoic Bikou Group, which was formed by the melting of the upper crust under the crustal thickening caused by the subduction and collision of the Qinling microplate. Subsequently, the dykes were transported along a tectonically weak zone, assimilating surrounding rocks and undergoing a transformation from “I”-type to “S”-type granite before finally evolving into granite with specific “A”-type characteristics. Our study provides new insights into the petrogenesis of granitic dykes in the Yangshan gold belt, as well as the relationship between gold mineralization and magmatic activity, which has significant implications for mineral exploration and the geological understanding of gold mineralization in this region. |
| first_indexed | 2024-03-11T02:08:04Z |
| format | Article |
| id | doaj.art-31a2aad663b64c4e9a040272f883d761 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-11T02:08:04Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-31a2aad663b64c4e9a040272f883d7612023-11-18T11:44:35ZengMDPI AGMinerals2075-163X2023-05-0113671810.3390/min13060718Petrogenesis of the Granitic Dykes in the Yangshan Gold Belt: Insights from Zircon U-Pb Chronology, Petrography, and In-Situ Hf Isotope AnalysisZhonghu Yang0Jianzhong Li1Tao Xiong2Yong Huang3Ciren Lamu4Yang Zhao5Wei Wei6College of Earth Science, Chengdu University of Technology, Chengdu 610059, ChinaCollege of Earth Science, Chengdu University of Technology, Chengdu 610059, ChinaResearch Center of Applied Geology, China Geological Survey, Chengdu 610036, ChinaResearch Center of Applied Geology, China Geological Survey, Chengdu 610036, ChinaResearch Center of Applied Geology, China Geological Survey, Chengdu 610036, ChinaResearch Center of Applied Geology, China Geological Survey, Chengdu 610036, ChinaResearch Center of Applied Geology, China Geological Survey, Chengdu 610036, ChinaThe Yangshan gold belt is renowned for its igneous rock formations, particularly dykes that form in tectonically weak zones. Some of these rock formations exhibit a close spatial relationship with gold mineralization, and a tiny portion of the granitic dykes serve as gold ore bodies by themselves. In order to investigate the nature of granitic dykes and their association with gold mineralization, we conducted a comprehensive study consisting of zircon U-Pb chronology, petrography, and in situ Hf isotope analysis of 25 granitic dyke samples collected from east to west across the belt. According to LA-ICP-MS zircon U-Pb dating results, the granitic dykes inherited zircon ages that are concentrated between 745.0 and 802.0 Ma, and magmatic intrusion ages that mainly fall between 201.0 and 213 Ma. Moreover, the granitic dykes display a calc-alkaline to high-K calc-alkaline peraluminous series, which is relatively enriched in light over heavy REE, with moderate Eu anomalies. These dykes are rich in large-ion lithophile elements and poor in high-field-strength elements. The zircon Lu-Hf isotope data range from εHf(t) values of −1.5 to 0.1, mantle model (T<sub>DM</sub><sup>1</sup>) ages range from 859 to 937 Ma, and crustal model (T<sub>DM</sub><sup>2</sup>) ages range from 1111 to 1218 Ma. The granitic dykes found in the Yangshan gold belt were formed between 200 and 213 Ma ago, during a period of intracontinental extension following the late collision between the Yangtze plate and Qinling microplates. These dykes originated from the volcanic basement of the Mesoproterozoic Bikou Group, which was formed by the melting of the upper crust under the crustal thickening caused by the subduction and collision of the Qinling microplate. Subsequently, the dykes were transported along a tectonically weak zone, assimilating surrounding rocks and undergoing a transformation from “I”-type to “S”-type granite before finally evolving into granite with specific “A”-type characteristics. Our study provides new insights into the petrogenesis of granitic dykes in the Yangshan gold belt, as well as the relationship between gold mineralization and magmatic activity, which has significant implications for mineral exploration and the geological understanding of gold mineralization in this region.https://www.mdpi.com/2075-163X/13/6/718Western Qinling OrogenYangshan gold beltgranite dykesgeochemistryzircon chronologyHf isotope |
| spellingShingle | Zhonghu Yang Jianzhong Li Tao Xiong Yong Huang Ciren Lamu Yang Zhao Wei Wei Petrogenesis of the Granitic Dykes in the Yangshan Gold Belt: Insights from Zircon U-Pb Chronology, Petrography, and In-Situ Hf Isotope Analysis Minerals Western Qinling Orogen Yangshan gold belt granite dykes geochemistry zircon chronology Hf isotope |
| title | Petrogenesis of the Granitic Dykes in the Yangshan Gold Belt: Insights from Zircon U-Pb Chronology, Petrography, and In-Situ Hf Isotope Analysis |
| title_full | Petrogenesis of the Granitic Dykes in the Yangshan Gold Belt: Insights from Zircon U-Pb Chronology, Petrography, and In-Situ Hf Isotope Analysis |
| title_fullStr | Petrogenesis of the Granitic Dykes in the Yangshan Gold Belt: Insights from Zircon U-Pb Chronology, Petrography, and In-Situ Hf Isotope Analysis |
| title_full_unstemmed | Petrogenesis of the Granitic Dykes in the Yangshan Gold Belt: Insights from Zircon U-Pb Chronology, Petrography, and In-Situ Hf Isotope Analysis |
| title_short | Petrogenesis of the Granitic Dykes in the Yangshan Gold Belt: Insights from Zircon U-Pb Chronology, Petrography, and In-Situ Hf Isotope Analysis |
| title_sort | petrogenesis of the granitic dykes in the yangshan gold belt insights from zircon u pb chronology petrography and in situ hf isotope analysis |
| topic | Western Qinling Orogen Yangshan gold belt granite dykes geochemistry zircon chronology Hf isotope |
| url | https://www.mdpi.com/2075-163X/13/6/718 |
| work_keys_str_mv | AT zhonghuyang petrogenesisofthegraniticdykesintheyangshangoldbeltinsightsfromzirconupbchronologypetrographyandinsituhfisotopeanalysis AT jianzhongli petrogenesisofthegraniticdykesintheyangshangoldbeltinsightsfromzirconupbchronologypetrographyandinsituhfisotopeanalysis AT taoxiong petrogenesisofthegraniticdykesintheyangshangoldbeltinsightsfromzirconupbchronologypetrographyandinsituhfisotopeanalysis AT yonghuang petrogenesisofthegraniticdykesintheyangshangoldbeltinsightsfromzirconupbchronologypetrographyandinsituhfisotopeanalysis AT cirenlamu petrogenesisofthegraniticdykesintheyangshangoldbeltinsightsfromzirconupbchronologypetrographyandinsituhfisotopeanalysis AT yangzhao petrogenesisofthegraniticdykesintheyangshangoldbeltinsightsfromzirconupbchronologypetrographyandinsituhfisotopeanalysis AT weiwei petrogenesisofthegraniticdykesintheyangshangoldbeltinsightsfromzirconupbchronologypetrographyandinsituhfisotopeanalysis |