| 云南保山卧牛寺组玄武岩成因：地幔柱活动的产物？ |
| |
| 引用本文： | 肖龙,徐义刚,梅厚钧,于荣萍.云南保山卧牛寺组玄武岩成因：地幔柱活动的产物？[J].岩石矿物学杂志,2003,22(1):20-28. |
| |
| 作者姓名： | 肖龙 徐义刚 梅厚钧 于荣萍 |
| |
| 作者单位： | 1. 中国科学院,广州地球化学研究所,广东,广州,510640
2. 桂林工学院,广西,桂林,541004 |
| |
| 基金项目： | 中国科学院知识创新资助项目 (KZCX2 - 10 1)，国家 973资助项目(G19990 4 32 0 5)，中国博士后科学基金资助项目(2 0 0 2 0 310 0 4 )，南京大学内生金属矿床成矿机制研究国家重点实验室测试基金资助项目 |
| |
| 摘 要： | 保山卧牛寺组玄武岩为低钛拉斑玄武岩，具有大陆板内玄武岩的特征，总体与蛾眉山玄武岩中的低钛玄武岩相似。其分异程度较高，富集大离子亲石元素和高场强元素，有明显的Nb、Ta负异常，Zr和Hf正异常，Eu无异常或弱负异常。该玄武岩由3个大喷发旋回形成3个岩石单元，其中下部早期第1单元由致密块状玄武岩、斜斑玄武岩、杏仁玄武岩和凝灰岩组成，第2和第3单元中见少量橄榄玄武岩和粒玄岩以及辉绿岩脉。有较高的^86Sr／^87Sr值(0．705966—0．706657)、较低的^143Nd／^144Nd值(0．512212—0．512283)，εNd(t)多为负值，源区为介于EMI和EMⅡ端员之间的富集岩石圈地幔。上述地球化学和同位素特征均可与蛾眉山玄武岩下部低钛拉斑玄武岩对比，表明该期岩浆作用可能同为地幔柱活动的产物，并暗示蛾眉山大火成岩省向西有很大的延伸。
|
| 关 键 词： | 卧牛寺组玄武岩 岩石成因 地球化学 地幔柱 |
| 文章编号： | 1000-6524(2003)01-0020-09 |
| 修稿时间： | 2002年7月29日 |
Petrogenesis of the basalts of Woniusi Formation at Baoshan area, Yunnan: Is it of mantle plume origin? |
| |
| XIAO Long,XU Yi_gang,MEI Hou_jun and YU Rong_ping.Petrogenesis of the basalts of Woniusi Formation at Baoshan area, Yunnan: Is it of mantle plume origin?[J].Acta Petrologica Et Mineralogica,2003,22(1):20-28. |
| |
| Authors: | XIAO Long XU Yi_gang MEI Hou_jun and YU Rong_ping |
| |
| Institution: | XIAO Long 1,XU Yi_gang 1,MEI Hou_jun 1 and YU Rong_ping 2 |
| |
| Abstract: | The basalts of Woniusi Formation at Baoshan area, located in western Yunnan Province, are composed of low_TiO 2 tholeiites generally similar to the low_Ti tholeiites from Emeishan large igneous province. They are highly_differentiated magmatites rich in large ion lithosphere elements and high field strength elements, have significant Zr and Hf positive anomalies as well as high 87 Sr/ 86 Sr and low 143 Nd/ 144 Nd ratios, and show characteristics similar to those of continental_rift basalts. Geochemically it consists of three eruption cycles which can be divided into three rock units. The early_stage unit 1 basalts are characterized by massive plagioclase_phenocryst basalts, amygdaloid basalts and basaltic tuff. The middle_stage unit 2 and the late_stage unit 3 consist of minor olivine basalts and trachybasalt as well as diabase dykes. From the similar geochemical and Sr_Nd isotopic features with Emeishan basalt, they are interpreted as the products that evolved from the same parent magmas and experienced crystal differentiation of plagioclase and clinopyoxene. Their parent magmas were generated from an enriched lithosphere mantle associated with mantle plume. This suggests that the Emeishan large igneous province may have remarkable westward extension. |
| |
| Keywords: | basalts of Woniusi Formation petrogenesis geochemistry mantle plume |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《岩石矿物学杂志》浏览原始摘要信息 |
| 点击此处可从《岩石矿物学杂志》下载免费的PDF全文 |
