香港花岗岩风化分级化学指标体系与风化壳分带

火成岩的化学风化过程实质上就是碱、碱土金属组分水解淋失与脱硅富铁铝化的地球化学过程。不同风化程度的岩石处于整个化学风化过程的不同阶段，因而具有不同的化学成分和风化度指标。笔者在对香港九龙两个地方5个钻孔共计150件不同深度、不同风化程度的样品化学全分析结果与岩土风化程度宏观判别结果的相互对比、选择和确认的基础上，建立了香港地区花岗岩风化岩土风化程度工程分级的化学指标体系。这一研究成果的提出不仅有利于提高花岗岩风化岩土工程分类的科。学性、可靠性和实用性，而且可以为风化岩土工程特性与风化作用关系研究提供理论依据。

CHEMICAL WEATHERING INDICES,CLASSIFICATION, AND ZONING OF WEATHERED GRANITIC ROCK IN HONG KONG

Chemical weathering of igneous rocks is principally a process of hydrolysi s, leaching loss of alkali and alkali earth metals, removal of silica and accu mulation of aluminum oxides. Rocks with different weathering degrees should po ssess distinctive chemical compositions,which thus can be used to develop variou s weathering indices. After studying 150 samples from various depths at two site sin Hong Kong, a set of chemical weathering indices is proposed to classify the weathered granitic rocks with different weathering degrees in Hong Kong. The pro posed chemical classification system provides not only a theoretical basis for i nvestigating the influence of weathering on engineering properties of weathered rocks, but also a scientific and reliable approach to classify the rocks with d ifferent degrees of weathering.