Geochemical Surveys

Geochemical Atlas of Hong Kong

An extensive geochemical database, comprising over one thousand whole rock major and trace element analyses and over two thousand stream sediment trace element analyses, has been established. In addition, a number of Rb-Sr and Sm-Nd isotope analyses and Rare Earth Element analyses of selected whole rocks have also been obtained. This wealth of geochemical information has permitted the geochemical characterisation of the various rock groups in the Hong Kong and has contributed to the establishment of natural background levels of elements. A Geochemical Atlas of Hong Kong, based on the results of a stream sediment geochemical survey (see below), has been published.

Age-Dating Projects

Age-dating of superficial deposits has been undertaken on a systematic basis in both onshore and offshore areas of Hong Kong. Techniques used to date these deposits include radiocarbon dating, optically-simulated luminescence dating and surface exposure dating using cosmogenic isotopes.

A comprehensive rock age-dating project has been underway in Hong Kong for several years with the primary aim of solving complex stratigraphic and structural problems. Dating methods have included isotopic systems such as K-Ar, Rb-Sr, U-Pb and Ar-Ar systems for dating volcanic and granitic rocks. Major advances in understanding of the volcanic stratigraphy and pluton emplacement history of Hong Kong have been achieved by using high precision U-Pb dating of zircon crystals. The provenance of sedimentary rocks has also been investigated using U-Pb dating of detrital zircon crystals.