| 松辽盆地北部营城组火山岩地球化学特征及地质意义 |
| |
| 引用本文： | 周翔.松辽盆地北部营城组火山岩地球化学特征及地质意义[J].吉林大学学报(地球科学版),2019,49(4):1001-1014. |
| |
| 作者姓名： | 周翔 |
| |
| 作者单位： | 大庆油田勘探开发研究院, 黑龙江 大庆 163712 |
| |
| 基金项目： | 国家自然科学基金项目（40372066）；国家重大科技专项项目（2016ZX05047-001） |
| |
| 摘 要： | 松辽盆地北部早白垩世营城组发育一套以流纹岩为主的中酸性火山岩，其具有高硅、铝，富碱和低镁、铁的特征，不同类型火山岩均具有轻稀土富集、重稀土亏损、轻重分异严重的特征。其中：酸性流纹岩表现为富集Pb、U、Th、Ta、Hf和Zr等元素，亏损Sr、Ba、Eu等元素；中性安山岩、粗安岩和基性玄武岩则亏损不明显；中酸性英安岩介于两者之间。地化特征分析表明，营城组岩浆来源于亏损地幔，是地幔底侵导致地壳部分熔融，并受到地幔物质的混染，酸性岩喷出前经历了较强的岩浆分异作用。构造判别图解指示营城组火山岩形成于板内伸展环境，具有与板块俯冲作用有关的、发育于活动陆缘或岛弧的火山岩类似的演化特征。结合中国东部构造环境演化特征，认为松辽盆地北部早白垩世火山活动可能是古太平洋板块北北西方向高速俯冲导致地壳岩石圈减薄、地幔物质上涌的产物。
|
| 关 键 词： | 地球化学特征 火山岩 营城组 早白垩世 松辽盆地 |
| 收稿时间： | 2018-06-06 |
Geochemistry and Tectonic Implication of Volcanic Rocks of Yingcheng Formation in Northern Songliao Basin |
| |
| Zhou Xiang.Geochemistry and Tectonic Implication of Volcanic Rocks of Yingcheng Formation in Northern Songliao Basin[J].Journal of Jilin Unviersity:Earth Science Edition,2019,49(4):1001-1014. |
| |
| Authors: | Zhou Xiang |
| |
| Institution: | Exploration and Production Research Institute, Daqing Oilfield, Daqing 163712, Heilongjiang, China |
| |
| Abstract: | The widely distributed Early Cretaceous volcanic rocks of Yingcheng Formation in northern Songliao basin are intermediate-felsic rocks, which are mainly rhyolites, characterized by high silicon, aluminum,rich alkali,and low magnesium and iron. The standard curve of rare earth elements reveals the deficiency of heavy rare earth elements,but the enrichment of light rare earth elements, and the rare earth elements are seriously differentiated in different kinds of volcanic rocks. The rhyolites are distinctly enriched in incompatible elements such as Pb, U, Th, Ta, Hf, Zr, and apparently loss of Sr, Ba, Eu, while in neutral andesite, trachyandesite and basic basalt they have no obvious loss, and in the intermediate-acid dacite they are in between. The results show that the magma of Yingcheng Formation originated form depleted mantle. Because the magma was contaminated by crust during evolution under magma plating and crust partial melting, forceful magmatic differentiation occurred before the eruption of acid magma. The volcanoes of Yingcheng Formation may erupt in an extensional background within plate according to the discrimination diagrams, and the volcanic rocks of Yingcheng Formation have the same evolutionary characteristics as those of the volcanic rocks developed in active continental margin or island arc associated with plate subduction. Taking the tectonic environment of Eastern China into consideration, the large-scale volcanic action in the Early Cretaceous may be associated with the lithospheric thinning and mantle upwelling under the subduction of the Pacific plate toward northwest in a high speed. |
| |
| Keywords: | geochemistry volcanic rock Yingcheng Formation Early Cretaceous Songliao basin |
|
| 点击此处可从《吉林大学学报(地球科学版)》浏览原始摘要信息 |
| 点击此处可从《吉林大学学报(地球科学版)》下载免费的PDF全文 |
|
