The BGS Lexicon of Named Rock Units — Result Details

Tycwtta Mudstones Formation

Computer Code: TYC Preferred Map Code: Tyc
Status Code: Pending Upgrade
Age range: Hirnantian Age (OH) — Rhuddanian Age (SR)
Lithological Description: Turbidite mudstones, thinly interbedded within packets dominated either by laminated or burrowed hemipelagites. Sporadic thin turbidite sandstones. Locally slumped.
Definition of Lower Boundary: Sharp incoming of less silty mudstones, with units of burrowed and laminated hemipelagites, above the coarse silty micaceous mudstones of the Yr Allt Formation.
Definition of Upper Boundary: Taken at base of first pebbly mudstone or conglomerate of overlying Allt-Y-Clych Conglomerate.
Thickness: 350m
Geographical Limits: Central Wales, east of Tywi Anticline.
Parent Unit: Not Entered (?)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  Bed of River Wye, east of Tywcwtta, north of Newbridge on Wye. 
none recorded or not applicable
1:50K maps on which the lithostratigraphical unit is found, and map code used: