摘要
涠州岛基性火山岩比较发育,地表出露于中更新统石峁岭组和上新统湖光岩组。经初步研究认为属碱性玄武岩类,主要岩石种属为暗色碱性橄榄粗玄岩、暗色碧玄玢岩和相应的火山碎屑岩。它们在矿物组合、结构构造、岩石化学数值特征、里特曼标准矿物组合等方面都与钙碱性玄武岩不同。它们与相邻的雷琼地区碱性橄榄玄武岩、碧玄岩对比,各方面特点都很近似。掌握了这类岩石特点对今后在我区发现更多的同样岩石会有一定意义。
The basic volcanic rocks in Weizhou island are comparatively well developed, they are distributed in Lower Pleistocene Zhanjiang Formation underground and are outcropped in intermediate Pleistocene Shimaoling Formation and Ploistocene Huguangyan Formation on the ground. Based on the preliminary studies, they are believed to be alkali-basalts. The main kinds of them are dark-coloured alkalic olivine dolerites, dark-coloured basanites and related pyroclastic rocks. They are different from calc-alkalic basalts in minerals, textures and structures, petrochemical numerical values and association of Rittmann standard minerals, etc. But they are similar to the alkalic olivine basalts and basanites in neighboring Leiqiong area in various aspects of above characteristics. Mastering the characteristics of these kinds of rocks can make definite significances for finding more rocks of same kinds in Guangxi in the future.
