Two-episode Tectono-thermal Events of the Heyuan Fault in Late Cretaceous and Oligocene and their Tectonic Implications, Southernmost South China Block

• 作者: WANG Qiangmao LI Hailong LI Tingdong DING Xiaozhong ZHEN Junwei ZHANG Min FAN Yanxia
• 来源期刊: 地质学报（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: ORIGINAL ARTICLES
• 页码范围: 447-459
• 页数: 13页
• 语种: 英文

摘要

The Heyuan Fault, is one of the main NE-trending faults in the southernmost South China Block and is close to the northernmost South China Sea to the south. The fault features multi-stage deformation and controlled the formation of late Cretaceous to Cenozoic basins. Based on detailed field investigations and comprehensive geochronological research, including zircon U-Pb, Rb-Sr isochron, zircon U-Th-He dating, two episodic tectono-thermal events are recognized. The first occurred during ～79 Ma to 66 Ma, which is characterized by large-scale quartz-fluid emplacement. The other occurred at ～34 Ma, which features the eruption of a set of basalts. The two events show a changing on material source from siliceous hydrotherm to basalt magma, supporting obvious lithospheric thinning of the southernmost South China Block, which shed light on the geological evolution and the interaction mechanisms between the SCB and the northern South China Sea since the Late Cretaceous.