Geochronological Framework and Geodynamic Implications of Mafic Magmatism in the Liaodong Peninsula and Adjacent Regions, North China Craton |
| |
| Authors: | LI Zhuang CHEN Bin and WANG Jialin |
| |
| Institution: | 1 The Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing 100871, China;,2 School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, 230009, Anhui, China and 1 The Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing 100871, China; |
| |
| Abstract: | Mafic rocks are widespread on the Liaodong Peninsula and adjacent regions of the North China Craton. The majority of this magmatism was originally thought to have occurred during the Pre‐Sinian, although the precise geochronological framework of this magmatism was unclear. Here, we present the results of more than 60 U‐Pb analyses of samples performed over the past decade, with the aim of determining the spatial and temporal distribution of mafic magmatism in this area. These data indicate that Paleoproterozoic–Mesoproterozoic mafic rocks are not as widely distributed as previously thought The combined geochronological data enabled the subdivision of the mafic magmatism into six episodes that occurred during the middle Paleoproterozoic, the late Paleoproterozoic, the Mesoproterozoic, the Late Triassic, the Middle Jurassic, and the Early Cretaceous. The middle Paleoproterozoic (2.1–2.2 Ga) mafic rocks formed in a subduction‐related setting and were subsequently metamorphosed during a ca. 1.9 Ga arc–continent collision event The late Paleoproterozoic (ca. 1.87–1.82 Ga) bimodal igneous rocks mark the end of a Paleoproterozoic tectonothermal event, whereas Mesoproterozoic mafic dike swarms record global‐scale Mesoproterozoic rifting associated with the final breakup of the Columbia supercontinent The Late Triassic mafic magmatism is part of a Late Triassic magmatic belt that was generated by post‐collisional extension. The Middle Jurassic mafic dikes formed in a compressive tectonic setting, and the Early Cretaceous bimodal igneous rocks formed in an extensional setting similar to a back‐arc basin. These latter two periods of magmatism were possibly related to subduction of the Paleo‐Pacific plate. |
| |
| Keywords: | mafic rocks geochronology Liaodong Peninsula tectonic setting |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《Acta Geologica Sinica》浏览原始摘要信息 |
| 点击此处可从《Acta Geologica Sinica》下载免费的PDF全文 |
|
