Computer Code: |
TRF |
Preferred Map Code: |
Trf |
Status Code: |
Pending Upgrade |
Age range: |
Ediacaran Period (AD)
— Comley Series (EC) |
Lithological Description: |
Felsic pyroclastic and extrusive rocks interbedded with shallow water sediments. Lithologies comprise volcanastic breccias, crystal tuffs, porphyritic rhyolitic lavas and thinly interbedded quartzose sandstones, tuffs, lapillistone and mudstone. |
Definition of Lower Boundary: |
Not defined - contacts mostly faulted. |
Definition of Upper Boundary: |
Unknown - unconformably overlain by mudstones and sandstones of the Solva Group (Cambrian) |
Thickness: |
Unknown - at least 15m proved in boreholes around Llandeloy. |
Geographical Limits: |
Pembrokeshire. |
Parent Unit: |
Not Applicable (-)
|
Previous Name(s): |
none recorded or not applicable
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Area |
Around Treffynnon, near St. David's, Pembrokeshire, South Wales. |
Reference Section |
Quarries in village of Treffynnon. Williams, T G. 1934. |
Reference(s): |
Allen, P M and others. 1985. Exploration for porphyry-style copper mineralisation near Llandeloy, southwest Dyfed. Mineral Reconnaissance Programme Report No 78, British Geological Survey, Keyworth, Nottingham, 99pp. |
Williams, T G. 1934. The Precambrian and Lower Palaeozoic rocks of the eastern end of St David's Precambrian area Pembrokeshire. Quarterly Journal of the Geological Society, London, Vol.90, 32-75. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E209
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