Table 6.3 - Summary of the field and petrographic characteristics of the Kwai Chung Suite
KWAI CHUNG SUITE
| UNIT | Hok Tsui Rhyolite | South Lamma Granite | Sham Chung Rhyolite | Needle Hill Granite | East Lantau Rhyodacite | East Lantau Rhyolite | Sha Tin Granite |
|---|---|---|---|---|---|---|---|
| Colour | pinkish white | light pink | grey | light grey or white | pinkish white | pinkish white | grey or pinkish mauve |
| Rock Type | quartzphyric rhyolite | biotite monzogranite | rhyolite | monzogranite | rhyodacite to rhyolite | rhyolite | biotite monzogranite |
| Dominant texture | porphyritic fine grained | equigranular medium grained | porphyritic fine grained | inequigranular fine grained | porphyritic very fine grained | porphyritic very fine grained | inequigranular, coarse to fine grained |
| Mafic minerals | biotite | biotite | biotite | biotite | biotite | biotite | biotite, hornblende |
| Feldspar | albite | microcline, mesoperthite, albite | perthite, albite | mesoperthite, albite | zoned oligoclase | zoned oligoclase | microcline zoned oligoclase |
| Accessory minerals | zircon | zircon, titanite, allanite, fluorite, Fe-oxide | zircon, allanite, Fe-oxide | zircon, fluorite, muscovite | zircon, apatite, allanite, Fe-oxide | zircon, allanite, apatite, fluorite, Fe-oxide | zircon, titanite, allanite, apatite, Fe-oxide |
| Alkali feldspar megacrysts | absent | absent | sparse | sparse | common | common | common |
| Pluton shape | (dyke swarm) | circular | (sill) | elliptical | (dyke swarm) | (dyke swarm) | elliptical |
| Area exposed (km2) | <1 | 12.5 | 1.5 | 16 | 20 | 15 | 50 |
| Mineralization | - | - | - | W,F,Sn | - | - | - |