Geological field trip to the North Eastern Islands of Hong Kong
with Chris Fletcher
Sunday, 20 October 2002 Following the successful event last year, Professor Chris Fletcher, Director of the Applied Geoscience Centre, Hong Kong University, will lead another geological field trip to the Kat O Chau (Crooked Island) and Ap Chau, the most northern islands in Hong Kong. The trip involves a drive through some of Hong Kong's most beautiful countryside, followed by a boat cruise with buffet lunch on board. The boat trip will pass close to Bluff Head where vertical sandstones and shales are exposed. They are the oldest (Devonian) rocks in Hong Kong and have been tilted to the vertical by earth movements associated with the fault that runs along Tolo Channel. The boat will continue past Wong Wan Chau (Double Island) where you can see the trace of a major fault that has thrust Jurassic volcanic rocks (165 million years old) over younger Cretaceous sedimentary rocks (70 million years old) during immense earth movements. Entering Double Haven and Crooked Haven it is possible to admire the remote beauty of this part of Hong Kong. A stop will be made at Ap Chau, where we will stroll along the beach to see a perfectly formed natural sea arch in the sedimentary breccias that are part of the youngest rock sequence in Hong Kong. The boat will make another stop at Kat O Chau, which supports one of the last remaining fishing villages in Hong Kong, with its fish farms, small square complete with banyan tree, a narrow shopping street selling dried fish and other marine life, and an interesting old temple. We will take the path across the island to the northern shore where some folded limestone beds (the only outcrop of limestone in Hong Kong) and a wide fault zone containing thick veins of white quartz veins are exposed. The boat will return along the eastern shores of Crooked and Double islands. The trip gives a chance to visit an isolated and inaccessible part of Hong Kong, to see some of the oldest and youngest rocks of the territory, to gain first hand experience of the effects of ancient mountainbuilding events and to visit an old fishing village.