摘要
笔者通过鄂尔多斯盆地南缘地区中奥陶统火山凝灰岩的岩石化学特征研究，认为该区的火山凝灰岩分属钙碱质系列和拉斑玄武岩系列，并根据σ－τ指数图解及其他判别指标，确定火山凝灰岩为岛弧喷发产物，这为进一步分析中奥陶世构造环境提供了依据。
On the basis of the research of the petrochemical characteristics of volcanic tuff fromMid-Ordovician series in the southern margin area of the Ordos Basin, the author consid-ers that the volcanic tuff of this area belongs to calc-alkaline rock series and tholeiite seriesrespectively. According to δ-τ index diagrams and other judgement indexes,the author al-so believes that volcaiiic tuff is an island arc eruption product.This provides evidences forthe further analvsis of tectonic environments in Middle Ordovician epoch.
出处
《石油实验地质》
CAS
CSCD
北大核心
1995年第2期167-170,共4页
Petroleum Geology & Experiment
