The BGS Lexicon of Named Rock Units — Result Details

Pysgotwr Grits Formation

Computer Code: PTR Preferred Map Code: Ptr
Status Code: Full
Age range: Telychian Age (ST) — Telychian Age (ST)
Lithological Description: Thinly interbedded turbidite sandstones and mudstones with abundant thicker beds of argillaceous coarse sandstone.
Definition of Lower Boundary: Base of lowest thick argillaceous sandstone bed above the lower tongue of the Glanyrafon Formation.
Definition of Upper Boundary: Top of highest thick argillaceous sandstone bed below the upper tongue of the Glanyrafon Formation.
Thickness: Up to 300m.
Geographical Limits: Central Wales.
Parent Unit: Cwmystwyth Grits Group (CWY)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  Pysgotwr Fawr stream section north-west of Bryn-Glas. 
Davies, K A, 1933. The geology of the area between Abergwesyn ( Breconshire) and Pompsaint (Carmarthenshire). Quarterly Journal Geological Society, London, Vol. 89, 172-200. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E195 E179