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The Geology of Hong Kong (Interactive On-line)
Lok Ma Chau Formation - Csl

Lok Ma Chau Formation, Csl

Carboniferous metamorphosed sedimentary rocks with ages ranging from approximately 354 to 280 million years before present. The Lok Ma Chau Formation stratigraphically overlies the Yuen Long Formation.

Distribution: The rocks of Lok Ma Chau Formation are present in the northwestern New Territories in a northeast-trending outcrop and subcrop stretching from Tuen Mun to Lo Wu, and also between the three islands of West Brother, East Brother and Reef Island.

Lithology: The Lok Ma Chau Formation consists of metamorphosed sandstone and carbonaceous siltstone with graphitic interbeds and conglomerate.

Depositional Environment: The Lok Ma Chau Formation has been interpreted in terms of deposition in neritic swamps within a prograding deltaic environment.

(Graphitic siltstone of the Mai Po Member, Lok Ma Chau Formation, West Brother island)