1 - HKU Libraries

More documents

Recommendations

Info

DetailsTai O. Extensive intertidal deposits occur in the sheltered creek at Tai O. They are almost 1 km wide to the southof the town, although the landward side has been bunded and ponds constructed (038 125) and reclamation fillplaced over the central area to construct an extension to the town (042 128). The creek is tidal and mangrovespersist in places, although many have been cleared. To the north of the town (041 132), the deposits are reclaimedfor agriculture and a pattern of fields has been established.Sham Wat Wan. The intertidal deposits of Sham Wat Wan are about 200 m wide. Numerous boulders andcobbles on the surface have been exhumed from the underlying slope deposits by wave action. The deposits arefringed by mangrove, particularly on the southeast side of the bay. Small sand bars have formed near the high tidelevel between the alluvium of the valley and the intertidal sediments.Tung Chung. Intertidal deposits in Tung Chung Bay are up to 400 m wide and form a fringing strip about 2400 mlong. They are characterized by extensive sandy splays and mangrove-lined channels.Chek Lap Kok (prior to development). There was an unusual development of intertidal deposits, an extensive,shallow fan, largely derived from excavations at the kaolin mine and adjacent test embankment (105 186). Thedeposit consisted of fine sand and silt, produced by washing of the kaolinized granite to the east.Yam O Wan. Prior to construction of the North Lantau Expressway, in Yam O Wan, a northeast-trending inlet,grey, silty intertidal mudflats, up to 300 m wide, fringed the seaward end of coastal slope deposits that extendedseawards into the bay.Shui Hau Wan. In this sheltered east-facing bay, very extensive intertidal mudflats, up to about 700 m wide, havedeveloped as a seaward extension of the low-lying, alluviated valley at Shui Hau, Mangrove-lined creeks are afeature of the flats. The deposits are relatively sandy.Tung Wan. A restricted development of intertidal deposits occurs in the southern bay at Tung Wan, south of theCountry Park Management Centre. The area has been modified by development,Yi O, Intertidal mudflats, up to 400 m wide, cover the floor of the shallow bay at Yi O. The deposits consist of agrey, sandy silt, with numerous cobbles on the surface, indicating they they are probably a winnowed slope deposit,being a seaward extension of the low gradient slope deposit from the adjacent valleys.Ngau Tau Wan - Tai Ho Wan. Tai Ho Wan consists of a tidal mud and sand flats, fringed by mangroves. Theclean sandy beach is marked by a sharp break in slope near high water mark.Offshore Superficial DepositsClassification and DistributionThe Hong Kong Geological Survey has previously subdivided the offshore superficial depositsinto the Hang Hau and Chek Lap Kok formations, based on lithological and palaeontologicalevidence from boreholes, and on interpretations of seismic characteristics (Strange & Shaw,1986; Langford etal, 1989; Strange*; al, 1990). The Hang Hau Formation is younger than theChek Lap Kok Formation. A new formation, the Sham Wat Formation, has been recognised onseismic profiles from the district. Stratigraphically, it lies below the Hang Hau Formation and,within the district, above the Chek Lap Kok Formation, It has a diagnostic seismic signature andappears, from limited borehole evidence, to have recognisable sedimentological andpalaeontological characteristics,A distinctive seismic sequence of very limited extent has been recognised above the rocWieadreflector in the Brothers - Ma Wan Channel This sequence is inteipreted as older than the ChekLap Kok Formation and has been designated as pre-Chek Lap Kok Formation deposits, but ithas not been given formational, or member status. In addition, Channel and TransgressiveDeposits118
Plate 46 - Raised Sand Bar or Dune behind the Present Sandy Beach at Pui O (156 113). Mangroveand Swamp Lie behind the Beach, Adjacent to the Tidal Stream Channel, Pui O WanPlate 47 - Sandy Beach with a Broad Intertidal Zone Composed of Muddy Sand (1562 1125),Pui O Wan
Page 2 and 3:
UNIVERSITY OF HONG KONGLIBRARIES
Page 4 and 5:
© Government of Hong KongPublished
Page 7 and 8:
CONTENTSTitle pagePage1ForewordCont
Page 9 and 10:
Distribution and Lithology 73Detail
Page 11 and 12:
Chapter 10 Economic Geology 149Intr
Page 13 and 14:
(Plates)Plate 22 - Porphyritic Medi
Page 15:
Table 1 — Grain Size Description
Page 18 and 19:
0 1 2 3 4 5 k mCONTOURS AT 100m INT
Page 20 and 21:
properties of the marine deposits b
Page 22 and 23:
Archival DataAll records from the s
Page 24 and 25:
Chapter 2Outline of GeologyThe soli
Page 26 and 27:
The Mesozoic volcanic rocks are div
Page 29 and 30:
Chapter 3Palaeozoic Sedimentary Roc
Page 31 and 32:
Carboniferous metasedimentaiy rocks
Page 33 and 34:
Plate 1 - Fining-Upward Sequence of
Page 35 and 36:
Plate 3 - Well-bedded Sandstones an
Page 37 and 38:
Reef Island. The northern end of th
Page 39 and 40:
Table 3. Evolution of Nomenclature
Page 41 and 42:
are crudely stratified and welded i
Page 43 and 44:
Shing Mun FormationThe type localit
Page 45 and 46:
Tai Che Tung. Crystal tuff, interpr
Page 47 and 48:
Plate 7 • Lapilli-Ash Crystal Tuf
Page 49 and 50:
Plate 11 - Pyroclastic Breccia (086
Page 51 and 52:
appears fragmental, and contains mu
Page 53 and 54:
exposures in the stream bed consist
Page 55 and 56:
Lin Fa Shan. The steep eastern flan
Page 57 and 58:
dipping northwest at 46°, is prese
Page 59 and 60:
Sunset Peak MemberThe Sunset Peak M
Page 61 and 62:
Plate 16- Block and Lapilli-bearing
Page 63 and 64:
Chapter 5Major IntrusionsClassifica
Page 65 and 66:
in grain size from 0.4 to 1.5 mm, a
Page 67 and 68:
20 - Megacrystic Medium-grained Gra
Page 69 and 70: Pui O Wan. Porphyritic medium-grain
Page 71 and 72: minimum age of c. 145 Ma (see earli
Page 73 and 74: The granite on Chek Lap Kok is most
Page 75 and 76: Southeast of Tin Sam, on the wester
Page 77 and 78: About 1 km east of Nam Shan, exposu
Page 79 and 80: Plate 25 - Thin Section of Porphyri
Page 81 and 82: Chapter 6Minor IntrusionsIntroducti
Page 83 and 84: The microgranite grades southwards
Page 85 and 86: the Lantau Formation, however, and
Page 87 and 88: Plate 29 - Flow-banded Quartzphyric
Page 89 and 90: also cut volcanic rocks of the Tsue
Page 91 and 92: Silver Mine Bay. On the headland so
Page 93 and 94: Plate 33 - Core stone Development i
Page 95: Plate 37 - Thin Section ofLamprophy
Page 98 and 99: Pre-Yensfaanlan StructureWithin the
Page 100 and 101: separates areas of different lithol
Page 102 and 103: NeotectonicsFault activity in the r
Page 105 and 106: Chapter 8Metamorphism and Alteratio
Page 107 and 108: the majority of rocks in the distri
Page 109: Chapter 9Superficial GeologyIntrodu
Page 112 and 113: Detailstal O. Alluvial deposits for
Page 114 and 115: trains. The regolith on most steep
Page 116 and 117: Plate 44 - Boulder Debris on the So
Page 118 and 119: gazetted for recreational purposes.
Page 122 and 123: Plate 48 - Sandy Beach at Fan Lau S
Page 124 and 125: Pre-Chek Lap Kok Formation Deposits
Page 126 and 127: formation. The sequence is usually
Page 128 and 129: BOREHOLE NO: ESC 17GRID REFERENCE:
Page 130 and 131: BOREHOLE NO: A5/1GRID REFERENCE: 80
Page 132 and 133: formation, thinly laminated clays o
Page 134 and 135: Quinqueloculina seminulum, which is
Page 136 and 137: Channel and Transgressive Deposits.
Page 138 and 139: Figure 20 - Areas of Acoustic Turbi
Page 140 and 141: West Lamma Channel These may be att
Page 142 and 143: Figure 23 - Depth-Averaged, Maximum
Page 144 and 145: The formation is Holocene in age. T
Page 146 and 147: Boreholes (A5/1, A5/2, B2/1, ESC17
Page 148 and 149: Plate 51 - Deep Weathering Profile
Page 151 and 152: Chapter 10Economic GeologyIntroduct
Page 153 and 154: Non-metalliferous MineralsFissure v
Page 155 and 156: REFERENCESAddison, R. (1986). Geolo
Page 157 and 158: James, J.W.C. (1993). The offshore
Page 159 and 160: Sewell, R.J., Strange, PJ., Langfor
Page 161 and 162: Appendix 1Microfossils identified f
Page 163 and 164: Appendix 2 (continued)Sample HK9913
Page 165 and 166: Appendix 2 (continued)Sample HK1054
Page 167 and 168: Appendix 4aSelective normalized pal
Page 169 and 170: ,Appendix 5 -Radiocarbon and Other
Page 171 and 172:
construction materials 151contact m
Page 173 and 174:
molybdenite 149Mong Tung Hang 151Mo
Page 175 and 176:
talus 107,115Tarn Tsui Wan 71,87Tan
Page 177:
LB 555.125 G34 LGeology of Lantaii
show all

1 - HKU Libraries

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?