Stratigraphy: Jurassic volcanic rocks with an age of approximately 147.5 ± 0.2 to 146.6 ± 0.2 million years before present.

Distribution: The Lantau Volcanic Group (undifferentiated) crops out in the west, southwest and south of Lantau Island.

Lithology: Dominantly fine ash vitric tuff and flow-banded rhyolite lava with minor eutaxitic coarse ash crystal tuff.

(Complex flow banding and folding in rhyolite lava of the Lantau Volcanic Group (undifferentiated), Nei Lak Shan, Lantau Island)