香港的新构造断裂活动与天然山体滑坡关系的初步研究

Preliminary Study of Neotectonic Fault Movement and Its Effect on Natural Terrain Landslides in Hong Kong

香港沙田河沥背地区西北向断裂的左旋错断构造运动,在断裂两分支之间造成转变挤压型地块抬升,形成一菱形地垒。表土层大致均匀分布在地垒及其两侧地区,并且没有被西北向断裂错动。而表土层所覆盖的古台地亦没有经过明显剥蚀。待得到河沥背表土层及邻近黄竹洋村天然山体滑坡定年结果资料,即可以给出河沥背断裂最新错动年龄范围及断裂活动与区内天然山体滑坡事件的相互关系。

A horst was formed within a compression sector between two subsidiary branches of a NW-trending left lateral strike-slip fault in the Ho Lek Pui area, Sha Tin, Hong Kong. Subsequent deposits on either side of the horst block are of uniform thickness and show no evidence for displacement by recent fault movement. The rhomb-shaped horst block appears not to have been substantially modified by erosion prior to deposition of the superficial deposits. Age data from samples recovered from the superficial deposits provide constraints on the timing of last fault movement. Comparison between these age data and those from a large-scale relict natural terrain landslide in the adjacent Wong Chuk Yeung area may help to establish a relationship between movement on the Ho Lek Pui fault and its effect on the surrounding natural terrain.