Stratigraphy: Cretaceous intrusive rocks with an age of approximately 136 ± 0.1 million years before present.

Distribution: The Mount Butler Granite forms small, subcircular intrusions on the southeast and east margins of the Kowloon Granite on Hong Kong Island and in eastern Kowloon.

Lithology: Equigranular fine- and fine- to medium-grained biotite granite.

(Equigranular, fine-grained Mount Butler Granite, eastern Kowloon)