Stratigraphy: Cretaceous dykes with an age of approximately 140 million years before present.

Distribution: The Tei Tong Tsui Quartz Monzonite occurs as several east- to northeast-trending stocks and dykes outcropping in the central and southeasterm New Territories,and on Hong Kong Island.

Lithology: Porphyritic fine- to medium-grained quartz monzonite.

(Well-developed Corestones in Tei Tong Tsui Quartz Monzonite, at Tai Miu Wan, Southern Clear Water Bay Peninsula)