Lantau Island
The Lantau dyke swarm is located on east Lantau Island. It is a group of vertical sheets of rocks formed by magma and lava flowing into northeast trending cracks in pre-existing granitic rocks on Lantau Island. Those cracks were related to the northeast trending faults. The Lantau caldera, which was the volcanic centre of the magma, is also bounded by faults and exhibits an elongated shape towards the northeast. These structures recorded the active strike-slip motion of the northeast trending faults in Lantau Island during Late Jurassic. (~148 million years ago).