RELATIVEWEATHERING RATES OF TUFF BLOCKS FORM ING TONGX IAN GATE OF QUZHOU ANCIENT CITYWALL IN ZHEJIANG PROVINCE

Researchers in eng ineer ing geo logy and geomorpho logy alw ays pay close attention to the rock w eathering rate. Howver, it is diff icult to f ind the quantitat ive results o f rock w eathering rates because they are ex treme ly low under the natural env ironmen.t Th is paper stud ies the relativew ea thering rate o f tu ff b locks form ing the ancient c ity w a ll of Quzhou. The w eather ing th ickness contrasts betw een the tuff b locks and the adjacent quartz sand b lock are used to ca lculate the tuffw eather ing rate on the basis o f the quartz sand block. It is found tha t from the construction time inM ing Dynasty to presen,t the tuff b lock has an averaged w eathering rate of 0. 086mm per year.