Stratigraphy: Cretaceous volcanic rocks with an age of approximately 142.7 ± 0.2 million years before present.

Distribution: The Ap Lei Chau Formation occurs in the western and southern parts of Hong Kong Island.

Lithology: Eutaxitic fine ash vitric tuff.

(Eutaxitic fine ash vitric tuff of the Ap Lei Chau Formation, Ap Lei Chau, southwest Hong Kong Island)