Tolo Channel

Tolo Channel or Chek Mun Hoi Hap () is a channel south of Plover Cove in Hong Kong connecting Tolo Harbour to Mirs Bay. At Mirs Bay end, it is named North Channel.
The Chinese name "Chek Mun" means Red Gate. "Hoi Hap" is the modern term for a sea channel. It is named red gate for the distinctive red-coloured sedimentary rocks (rich in iron) to its north.
Geology.
The channel is the most obvious geologic fault in Hong Kong; the fault line runs in a south-westerly direction through Tide Cove towards Lai Chi Kok. The rocks at the north of the channel are sedimentary while those at the south are igneous. The rocks along the north coast of Tolo Channel and at Wong Chuk Kok Tsui are the oldest in Hong Kong.