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trains. The regolith on most steep slopes has crept to some degree. This is visible in section asoutcrop curvature of quartz veins, or debris trails from outcropping marker bands.The Holocene slope deposits are generally soft to firm, light yellowish-brown, slightly clayey,sandy silt to gravelly silty sand. Included clasts are slightly to moderately weathered, subangularto angular cobbles and boulders. The weathering rind on large boulders is never more than a fewmillimetres thick. Pleistocene slope deposits have a mottled, reddish-brown or white matrix,which is firm, stiff, or indurated, and clasts that are more highly weathered in places.DetailsTai O - Sha Lo Wan. Between Tai O and Sha Lo Wan the hillsides are characterised by extensive slope deposits.These grade downslope into alluvial fans as seen at Tai 0 (045 127) and at Sha Lo Wan (079 165). East of Tai 0fluvial and slope deposits of presumed Pleistocene age are exposed along the foreshore, unconforrnably overlyingCarboniferous sedimentary rocks of the Lok Ma Chau Formation (Plate 42). These superficial deposits are onshorelateral equivalents of the Chek Lap Kok Formation, identified in offshore seismic records and boreholes.Above Sham Wat Wan, Pleistocene slope deposits form a large, lobate mass (065 1 37) on the flanks of CheungShan, The deposits display a mottled, reddish-brown and white matrix., and clasts which are partially weathered insitu. The beach in front of the slope deposits is dominated by boulders and cobbles of both sedimentary andvolcanic rocks. The Lok Ma Chau Formation to the northeast and southwest of Sham Wat Wan produces a sharpridge line, which is a surface expression of the hard sedimentary rock. These hills are free of coarse slope deposits,but the volcanic rocks south of Sham Wat Wan have, in places, extensive spreads of boulder debris.San Shek Shan (071 158) is dominated by an extensive sheet of slope deposits from the adjacent steep hills. Thelower slopes of these hills are underlain by the Lok Ma Chau Formation, and are therefore relatively debris free,but the steep upper parts are in the volcanic rocks that are the source of much of the debris.Tung Chung. The most extensive debris deposits in the district occupy the western streams of the Tung ChungValley. A dendritic network of Pleistocene debris deposits feeds eastwards, from the flanks of Nei Lak Shan (097147) and adjacent hills, and a continuous valley lobe (121 125) feeds northwards for 2500 m from Tung Chung Au.The material is predominantly a coarse bouldery deposit, with well weathered boulders and cobbles in a stiff,mottled, sandy silt matrix. Downslope, the debris grades into extensive, partially indurated Pleistocene alluvialterrace deposits. Holocene debris deposits fill many of the minor valley heads, forming minor dendritic networksthat are not contiguous with the Pleistocene debris.A dendritic system of Holocene debris deposits fills the eastern valley (127 144) below Shek Sxe Shan and thenorthern slopes of Sunset Peak (136 146), receiving feeder lobes from Wo Liu Tun (122 149) and Pok To Yan (126157). The material is mostly cobbles with a predominantly sandy, unweathered matrix,Chek Lap Kok (prior to development). The largest area of slope debris occurred at Fu Tei Wan (111 181).Before the island was levelled, there was extensive agricultural terracing in the deposit, which was a relativelysmooth, steeply inclined accumulation of boulders and cobbles in a silty matrix. Sections were not seen, but oneborehole (L27/3427A, 11069 18326) passed through 4 m of yellowish-brown, clayey sand with gravel beforepassing into the underlying weathered bedrock. Artificially-terraced slope deposits occurred upslope of beachdeposits at Cheung Sha Lan (1 11 197), and marginal to the large alluvial tract ( II 5 1 95) at Sham Wan Tsuen. AtCheung Sha Lan the surface of the deposit comprised fine gravel and sand, with quarto vein debris prominent.Tie distribution of slope deposits were largely determined by surface morphology, They were generally restrictedto thin mantles on some of the steeper slopes, feeding narrow valley fills. The material appeared to be formedpredominantly by soil creep and slopewash, and contained few boulders, The largest areas of slope deposits arealong the two valleys connecting Fu Tei Wan and Sham Wan. Elsewhere they formed small patches in steephollows on hillslopes.fB ha " Ta * H ° Wan Extensive trains of boulder debris occur in most valleys on the northernflanks (124164) of Pok To Yan and For Kai Shan. These usually originate from rock ribs and ledges formed by upstandingdykes. Near Tai Ho Wan , very extensive debris deposits choke the valley system (159 169) to the south, To theeast, the side of the untamed hill (164 174) clearly displays coarse boulder streams, which are probably debrisnow deposits from which the fines have been eluviated, Further east, narrow boulder debris streams are also welldeveloped (Plate 43, 177 170) to the southwest of Lo Fu Tau.Tai Che Tung Extensive, linear boulder streams are well developed, filling valleys on the north slopes (188 198),Near the summit, small waterlogged hollows have formed in the deposits, most of which are boulder-free.