Stratigraphy: A swarm of quartzphyric rhyolite dykes that intrudes the Tai Po Granodiorite and the Yim Tin Tsai Formation at around 151.9 ± 0.2 million years before present.

Distribution: Hok Tsui Rhyolite is restricted to Cape D'Aguilar (Hok Tsui) in the extreme southeastern corner of Hong Kong Island.

Lithology: Quartzphyric rhyolite dykes.

(Flow-banded Hok Tsui Rhyolite dyke, Cape D'Aguilar, southeastern Hong Kong Island)