1 - HKU Libraries

and* This memoir describes the geology of Lantau and adjacent smaller islands. It should be read inconjunction with 1:20 000 Geological Map sheets 9 (Tung Chung), 10 (Silver Mine Bay), 13(Shek Pik) and 14 (Cheung Chau).* The memoir is one of a series that records the findings of the Hong Kong Geological Survey.An index of the memoirs and the 1:20 000 Geological Maps to which they relate is shown below.15^x*9 ,»** *6'• 3x** + * + *748910111213141516mapsmemoirs* Individual superficial deposits in onshore areas are not generally considered mappable if lessthan 2 m thick. In the offshore areas the material on the sea-bed is shown, in most casesregardless of thickness.* Grid references are based on the Hong Kong 1980 Metric Grid as shown on the 1:20 000Geological Maps. Ten-figure references indicate positions to within 10 m, with Eastingsfollowed by Northings, e.g. 80672 81239. Eight-figure references indicate positions to within100 m. For convenience, however, the prefix figures 8, which apply to all eastings and northingsin the district, are omitted.* Hong Kong Principal Datum (PD) is 1.2 m below Mean Sea Level, and 0.15 m aboveAdmiralty Chart Datum. The bathymetric dontours shown on the 1:20 000 Geological Maps arebased on Port Works Division surveys, with supplementary data from Admiralty Charts, andsurveys by Electronic and Geophysical Services Ltd.* Samples in the Territory-wide rock collection archived by the Hong Kong Geological Surveyare prefixed HK followed by a serial number, e.g. HK 2263.* Boreholes are generally referred to by the contractor's number followed by the GeotechnicalInformation Unit (GIU), Civil Engineering Library, accession number for the relevant groundinvestigation report, e.g. 1201D/03412.* The system used in this memoir for grain size description and classification is summarized inTable 112