地质学报2025，Vol.99Issue(7)：2271-2283,13.DOI:10.19762/j.cnki.dizhixuebao.2024307
海南岛滨海断裂的构造活动历史及其动力学机制:来自磷灰石、锆石裂变径迹的证据
Tectonic activity history and its dynamic mechanism of the Binhai fault,Hainan Island:New evidences from apatite and zircon fission track analyses
摘要
Abstract
Hainan Island is the largest continental marginal island in the northwestern South China Sea,surrounded by Cenozoic rift basins such as the Qiongdongnan basin,Yinggehai basin,and Beibu Gulf basin.It constitutes the major footwall of the boundary fault of these basins.Therefore,the uplift and exhumation history of the Hainan Island provides important insights into the basin-range coupling process and preservation conditions for oil and ores.This study first reports the analytical results of apatite and zircon fission track analyses along the Binhai fault,the only basin-controlling fault that extends into the H ainan Island.The apatite fission track ages range from 23±2 Ma to 40±2 Ma with an average confinement track length of 12.2～13.2 μm,which is relatively small.The zircon fission track ages range from 63±3 Ma to 82±4 Ma,with single grain ages primarily concentrated in the age groups of 82～78 Ma and 72～69 Ma,respectively.The cooling history of Hainan Island since the Late Cretaceous is generally divided into three episodes.From the Late Cretaceous to the Early Paleocene(82～63 Ma),the Hainan Island experienced rapid uplift with a total exhumation amount of 3.3 km.During this period,the Hainan Island was affected by the NW compression caused by the subduction of the Pacific Plate,as well as by the expansion of the middle ridge of the ancient South China Sea.Additionally,the Baolun gold mine,located along the western margin of the Baisha Basin,experienced significant large-scale compressional deformation.From the Early Paleocene to the Middle Miocene(63～13 Ma),the samples experienced a prolonged period of slow cooling,except on the western side of the Binhai fault,where there was a rapid cooling from the Middle Eocene to the Late Oligocene(40～24 Ma).We attribute this rapid cooling period to the drag effect caused by the accelerated subduction of the Paleo-South China Sea,while the differential uplift on both sides can be linked to the reactivation of the Binhai fault.During this period,the coarse clasts exhumed from the Hainan Island serves as the key reservoir for the Cenozoic basin.Since the Middle Miocene(13～0 Ma),the exhumation amount is 1.93 km.The compression stress caused by the NNW wedge of the Philippine Sea plate,along with the long-distance effects of the India-Eurasia plate collision,has led to significant rapid compression and exhumation of the Hainan Island during this period.关键词
海南岛/南海/隆升剥蚀/冷却历史/印度-欧亚板块碰撞Key words
Hainan Island/South China Sea/uplift and exhumation/cooling history/India-Eurasia plate collision引用本文复制引用
林弟,郑勇,胡在龙,魏昌欣,袁勤敏..海南岛滨海断裂的构造活动历史及其动力学机制:来自磷灰石、锆石裂变径迹的证据[J].地质学报,2025,99(7):2271-2283,13.基金项目
本文为海南省海洋地质资源与环境重点实验室开放课题(编号HNHYDZZYHJKF014)、海南省自然科学基金(编号421RC1109)、中国地质调查局项目(编号1212011220710,DD20160035)和中国地质科学院基本科研业务费项目(编号JKYQN202314)联合资助的成果. （编号HNHYDZZYHJKF014）
