Reconstruction of site history of boulders near Shek Lung Tsai, Ma On Shan country park

Abstract

A study of the origin of the boulder fields at Shek Lung Tsai, Ma On Shan has been carried out because of the mystery surrounding their origin, which has yet to be formally investigated. The objective of the study was to give a descriptive analysis of the geometry of the boulders, and to examine if they are jointed columns like those of the High Island Formation in Sai Kung, by obtaining data on aspect ratio and interfacial angles. Data has been obtained from the boulders and is presented in the form of a table detailing their individual measurements. The data has been interpreted in relation to the concept that Y-intersections and hence interfacial angles of 120˚ are indicative of columnar-jointed rocks. It is concluded that there is a possibility of the boulders being cooling-jointed columns, and their failure may have been triggered by a tilting of southeastern Hong Kong to the east was as much as 30˚ in the Quaternary.