摘要
赣西地区下二叠统茅口组中的均密石英岩是一种特殊类型的硅质岩，广泛分布于萍乡、宜春、分宜、安福、莲花一带，具镶嵌均粒结构和“三连点”结构，颗粒界线平直。矿物成分以α－石英为主；化学成分中ＳｉＯ２含量达９５％以上，Ａｌ２Ｏ３、Ｆｅ２Ｏ３、ＣａＯ、ＭｇＯ含量低。这种岩石风化后．颗粒间易解体，形成具有工业价值的粉石英矿。它是由碳酸盐岩经硅质交代形成。ＳｉＯ２主要来源于母岩以及由粘土矿物分解和海泡石向滑石转化释放而来。
A specieal type of silicalite, in Maokou formation of the lower Permian series,is widely distributed in Ping-clang, Yichun, Fenyi, Anfu and Lianhua of the west part of Jiangxi Province. It is similar to the novacrulte found in Arkansns of the United States and possesses even grained mosaic texture and triple-point texture. The grains have regular contact boundaries. The silicatite consists mainly of α-quartz. In chemical composition, the rock is characterized by high content of SiO2 (over 95%), low content of Al2O3,CaO, and MgO. Such special textures and composition facilitated weathering and disintegration and led to the formation of tripoli deposit that has great value in industry. According to the auther's researches, the silicalite is formed as the consequence of replacement of carbonate rock by silica.The silica is derived mainly from the primary rock, the decompositon of clay minerals and the conversion from sepiolite to talc.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
1994年第1期104-110,共7页
Acta Petrologica Sinica
