Stratigraphy: Early Jurrasic sedimentary rocks.

Distribution: Tolo Channel Formation is confined to small exposures on both sides of Tolo Channel and to the south of Yuen Long, around the foothills of Tai Tong.

Lithology: The Tolo Channel Formation consists of grey laminated siltstone with interbedded fossiliferous black mudstone.

Depositional Environment: A shallow marine, sublittoral environment of depostion is inferred for the Tolo Channel Formation.

(Strongly deformed, laminated siltstone alternating with laminated fossiliferous mudstone of the Tolo Channel Formation, Fung Wong Wat, Tolo Channel, northeastern New Territories)