Hong Kong’s Columnar Rock Formation Recognised as IUGS Geological Heritage Site

A formation of towering volcanic rock columns in the Hong Kong UNESCO Global Geopark has been recognised as amongst the First 100 Geological Heritage Sites by the International Union of Geological Sciences (IUGS), according to a press release on Oct. 22.

Studies of the “High Island Formation” show that it is a relic of an early Cretaceous super volcano, which dates to around 140 million years ago. Notable dinosaurs from this period include Giganotosaurus and Microraptors.

Geologists believe the rock formation originated from a volcanic eruption that resulted in large amounts of volcanic ash and lava. When the volcano collapsed, it left a large caldera, or basin-like crevice, spanning 20 kilometres in diameter. The volcanic materials inside the caldera gradually cooled and contracted, forming unique and abundant hexagonal rock columns.

“The formation comprises many columns, which are large, well preserved and widely distributed, making it a globally rare and iconic geological wonder. The selection of the High Island Formation as one of the First 100 IUGS Geological Heritage Sites recognises its international importance,” said a spokesperson for the Agriculture, Fisheries & Conservation Department.

The “High Island Formation” ranks among sites such as the Shilin Karst in China, the Uluru Rock in Australia, and the Grand Canyon in the U.S.