摘要
综合应用Ｘ射线衍射、扫描电境、透射电镜及偏光显微镜等技术，研究了我国热带、亚热带地区花岗岩和片麻岩风化壳中的长石风化现象。研究区内的长石风化形式主要为化学风化，所形成的风化产物有０７ｎｍ埃洛石、高岭石、水云母类矿物、三水铝石、硅铝质凝胶等，其中以０７ｎｍ埃洛石分布最为广泛，三水铝石仅见于个别地区。０７ｎｍ埃洛石的形成经历了非晶质硅铝凝胶等中间相；高岭石的形成经历了水云母类矿物中间相；三水铝石的形成经历了非晶质硅铝凝胶或０７ｎｍ埃洛石等中间相。风化壳内部水溶液的物理化学性质、湿热的气候条件及母岩性质是影响风化产物形成的主要因素。
Feldspar weathering products from six weathered granite and gneiss crusts in tropic and subtropic areas of China are studied by means of X ray diffraction, electron microscopy and light microscopy. Products derived from weathering of feldspars are hydromica, 0.7 nm halloysite, kaolinite, gibbsite and amorphous form sialic materials, etc. The most widespread one among them is 0.7 nm halloysite. Gibbsite can only be observed in a faulted zone. Factors controlling the formation of weathering products include the humid and hot climate of research areas, dissolution rates and chemical properties of solutions in macro and micro environments in the crusts, mineralogical compositions and textures of parent rocks. Weathering of feldspars to 0.7 nm halloysite via an amorphous form material is generally favoured by a relatively open and leached environment. Transformation of feldspar to kaolinite was observed in a less open and leached environment than that needed for transformation of feldspar to 0.7 nm halloysite, and hydromica is usually a precursor for the formation of kaolinite. In lighly leached environment, feldspars have been converted to gibbsite through an intermediate 0.7 nm halloysite or amorphous form sialic material stage.
出处
《石油大学学报（自然科学版）》
CSCD
1998年第5期14-18,共5页
Journal of the University of Petroleum,China(Edition of Natural Science)
关键词
热带
亚热带
化学风
长石
风化产物
中国
China
tropical zone
subtropical zone
feldspar
weathering product
secondary mineral
