| Order | Type | Group | Form-ati | Member | Description | Upper | Lower | Basin |
| By No. | on | Age | Age |
| 3687.0 | SED | LWG | AYME | Aymestry Limestone | SU | WLDB |
| 3688.0 | LLUF | Lower Ludlow Formation |
| 3689.0 | CORG | Cambrian - Ordovician Group | E | O | CHE |
| 3690.0 | LCSF | Lower Cambrian Sandstone Formn |
| 3691.0 | TREM | Tremadoc Shales | ET | WSXB |
| 3692.0 | WOAK | White-leaved Oak Shales Equiv |
| 3693.0 | HOLY | Hollybush Sandstone |
| 3694.0 | TRMS | Tremadoc Series | ET |
| 3695.0 | GSLU | Grey Siltstone Unit | O | WLDB |
| 3696.0 | BAS | CALE | Pre-Permian Caledonian Basement | PB | C | SONS CNSB MOFI |
| 3697.0 | HERC | Pre-Permian Hercynian Basement | SU | ANPA |
| 3698.0 | STRN | Basement Strunian Quartzite | D | CARD |
| 3699.0 | GRTC | Granitic Basement | S | DT | MOFI |
| 3700.0 | METB | Metamorphic Basement | WCHB |
| 3701.0 | RBTC | Reworked Basement | E | S | SWAP |
| 3702.0 | CAER | Caerfaian Amphib.Granul.Gneiss | STCR COCB COHI |
| 3703.0 | NONM | Non-Metamorphic Basement | ZZ | CHE |
| 3704.0 | URCV | Urconian Volcanics |
| 3705.0 | TORR | Torridonian | NMH |
| 3706.0 | DALR | Dalradian | DD | HAPL EORB GRSP |
| 3707.0 | LTLE | Loch Tay Limestone Equivalent | MOFI |
| 3708.0 | MOIN | Moinian | MD | TO | HAPL EORB GRSP |
| 3709.0 | LEWS | Lewisian | LE | WSWO RWOR WSHP |
| 3710.0 | UNK | ABS | Absent |
| 3711.0 | UNDF | Undifferentiated |
| 3712.0 | NPR | Not Proven |
| 3713.0 | FZ | Fault Zone |
| 3714.0 | BAS | BSMT | Basement | S | D | NONS |
| 3715.0 | MDCR | Mid-Crustal | SWAP CARD CNSB |
| 3716.0 | UNK | * | Unknown |
| Page 60 of 60 | 07/07/2004 |