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The Geology of Hong Kong (Interactive On-line)
Sai Lau Kong Formation - Jtl

The Sai Lau Kong Formation (Table 5.4) is restricted to a northwest-trending outcrop in the northeastern New Territories where it conformably overlies the Tai Mo Shan Formation (Figure 5.7). At the type locality of Sai Lau Kong, the formation comprises dominantly dacite lava (Plate 5.19) with intercalated tuff-breccia, tuffaceous siltstone and sandstone (Figure 5.12). The Sai Lau Kong Formation is thought to be the final expression of Middle Jurassic volcanism belonging to the Tsuen Wan Volcanic Group. Hence, the U–Pb date of 164.1 ± 0.2 Ma obtained from the formation (Sewell et al., 1998) constrains the youngest age of the Tsuen Wan Volcanic Group. However, there is evidence of later intrusive activity related to this magmatism (see below).