geology
High Island's Rhyolitic Rock Columns
The High Island Formation records a major ancient volcanic system in the Sai Kung region. As deposited volcanic material cooled and contracted, fractures developed into columns. Unlike the basalt columns familiar at many other sites, these are silica-rich rhyolitic volcanic rocks, making their composition an important part of their geological interest.
Source: Hong Kong Agriculture, Fisheries and Conservation Department / Hong Kong UNESCO Global Geopark



