华北克拉通奥陶纪岩浆活动——来自河南安阳岭头地区白垩纪闪长岩中继承锆石U-Pb年龄的证据  

Ordovician magmatism in the North China Craton——Evidence from U-Pb age of the inherited zircon from Cretaceous diorite in Lingtou area,Anyang,Henan

作　　者：杨长青 巴燕 王艳慧 何凯 白国典 YANG Changqing;BA Yan;WANG Yanhui;HE Kai;BAI Guodian(Henan Academy of Geology,Zhengzhou,450001;Key Laboratory of Ore Forming Processes and Resources Utilization of Metal Minerals in Henan Province,Zhengzhou,450001)

机构地区：[1]河南省地质研究院,郑州450001 [2]河南省金属矿产成矿地质过程与资源利用重点实验室,郑州450001

出　　处：《地质论评》2023年第3期1150-1160,共11页Geological Review

基　　金：中国地质调查局项目(编号∶12120111219770)的成果。

摘　　要：通过高精度的LA-ICP-MS锆石U-Pb同位素测年,在太行山南段河南安阳县岭头一带白垩纪闪长质侵入岩中获得一批443.6±6.1 Ma(MSWD=6.3)的年龄数据,相当于晚奥陶世晚期,这是在华北克拉通内部发现的首例反映加里东期岩浆侵入活动的高精度锆石U-Pb定年数据,为揭示华北克拉通早古生代构造岩浆演化提供了依据。结合区域上同期构造岩浆事件的特点,认为443.6±6.1 Ma的锆石可能为华北克拉通板内裂解拉张作用的产物,它是奥陶纪晚期(440 Ma前后)古劳亚大陆分裂,华北克拉通漂离加拿大地盾和北美内陆地台,同时形成北太平洋———这一影响全球的构造地质事件在华北克拉通内部的响应。鉴于稳定克拉通地区奥陶纪岩浆侵入活动与金刚石原生矿存在极高的关联度,本次发现也为在鹤壁地区寻找金刚石原生矿提供了重要参考。An age of the 443.6 of Ma(MSWD=6.3)was obtained through LA-ICP-MS zircon U-Pb dating on zircons from the Cretaceous dioritic intrusive rocks in Lingtou area,Anyang County,southern Taihang Mountains,which is in late Late Ordovician.This is the first record of Caledonian magmatic intrusion activity found in the North China Craton,in addition to the Middle Ordovician kimberlite distributed along the Tancheng—Lujiang fault zone,which provides evidence for revealing the Early Paleozoic tectonic—magmatic evolution of the North China Craton.Combined with the characteristics of the regional tectonic—magmatic event in the same stage,we propose that there is an intraplate break-up event in 443.6±6.1 Ma.That is Late Ordovician(ca.440 Ma),the breakup of Paleo-Laurasia to create the North Pacific Ocean,caused that the North China Craton drift apart from Canada Shield and North American Platform——the response to the tectonic events affecting the global in North China Craton.In view of the high correlation between the Ordovician magmatic intrusion activity in the stable craton region and the primary diamond deposit,this finding also provides an important reference for the search of primary diamond deposit.

关 键 词：晚奥陶世 锆石U-PB年龄 华北克拉通 古劳亚大陆 太行山南段 鹤壁地区 

分 类 号：P534.53[天文地球—古生物学与地层学] P588.122[天文地球—地质学] P597.3