摘要
辽南梁屯-矿洞沟古元古代岩体包括坎子岩体、卧龙泉岩体、学校后街岩体与梁屯岩体,岩性分别为中细粒二长花岗岩、中细粒似斑状黑云母二长花岗岩、细粒黑云母二长花岗岩、细粒正长岩。学校后街岩体与梁屯岩体LA-ICP-MS锆石U-Pb年龄加权平均值为1 887.2±5.4 Ma、1 883.9±2.6 Ma,为古元古代。从坎子岩体到梁屯岩体岩石化学体现了一个偏铝-过铝型,钙碱性-碱性的演化序列,K及Mg O含量逐渐增高,富集大离子亲石元素K、Rb、Ba、Sr,亏损高场强元素Nb、Ta、Zr、Hf,稀土元素配分模式右倾,属具有负铕异常的轻稀土富集、重稀土亏损型。结合相关构造环境分析,古元古代岩体在辽河岩群沉积完成后存在着一个活动大陆边缘-碰撞造山-造山晚期,岩石类型由I型-S型-A型的演化过程。
The Paleoproterozoic rock mass in Liangtun-Kuangdonggou area of South Liaoning province include Kanzi rock mass,Wolongquan rock mass,Xuexiaohoujie rock mass,Liangtun rock mass.The LA-ICP-MS zircon U-Pb dating and geochemical characteristics of Xuexiaohoujie rock mass and Liangtun rock mass are（1 887.2 ±5.4） Ma,（1 883.9 ± 2.6） Ma,they were formed in Paleoproterozoic.The evolution sequence of Xuexiaohoujie rock mass and Liangtun rock mass is partial aluminum-aluminum and calcium alkalinity-alkalinity,so the rocks are belonged to high-K and MgO.Enrichment of large ion parent stone elements K,Rb,Ba,Sr,loss of high field strength elements Nb、Ta、Zr、Hf,the curve is obvious trend right on REE distribution pattern,suggesting that the rocks are the type of LREE enrichment and HREE depleted and with medium negative Eu anomaly.Combined with related tectonic environment analysis,after the deposition of the Paleoproterozoic rock mass in Liaohe Group,there is an active continental margin collisional orogenic late stage,and the evolution of the rock type is from I type-S type-A type.
作者
彭游博
王恩德
PENG You-bo;WANG En-de(Liaoning Survey Academy of Geology and Mineral Resources,Shenyang 110031,China;School of Resources and Civil Engineering,Northeastern University,Shenyang 110004,China)
出处
《科学技术与工程》
北大核心
2018年第20期41-50,共10页
Science Technology and Engineering
基金
中国地质调查项目(DD20160049
DD20160049-7)资助
