| UNIT | Yim Tin Tsai Formation |
Shing Mun Formation |
Tai Mo Shan Formation |
Sai Lau Kong Formation |
|---|---|---|---|---|
| Colour | grey | grey | grey | purplish grey |
| Composition | rhyodacite to rhyolite | rhyodacite to rhyolite | rhyodacite to rhyolite | rhyodacite to rhyolite |
| Lithologies | crystal tuff | crystal tuff, tuff breccia, tuffite | crystal tuff | dacite lava, tuff breccia, tuffite |
| Dominant texture | coarse ash | coarse and fine ash | coarse ash | porphyritic and coarse ash |
| Crystals | quartz and feldspar | quartz and feldspar | quartz and feldspar | feldspar and quartz |
| Lithics | rhyolite lava, volcanic rock fragments | rhyolite lava, marble, tuff, volcanic rock fragments | - | rhyolite lava, volcanic rock fragments |
| Glass/Pumice | - | rare | - | - |
| Fabric | massive to crudely bedded | massive to crudely bedded ± eutaxitic | massive | bedded, flow-banded |
| Thickness | 200 m | 600 m | >600 m | >300 m |