The BGS Lexicon of Named Rock Units — Result Details

Mynydd Tir-Y-Cwmwd Microgranite

Computer Code: MTGM Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Porphyritic microgranite composed of perthite phenocrysts with lesser plagioclase and minor green biotite in an equigranular, unfoliated, granophyric groundmass
Definition of Lower Boundary: Not seen.
Definition of Upper Boundary: Not seen.
Thickness: Unknown.
Geographical Limits: none recorded or not applicable
Parent Unit: Not Available (!)
Previous Name(s): Mynydd Tir-Y-Cwmwd Granophyric Microgranite (-1712)
Alternative Name(s): none recorded or not applicable
none recorded or not applicable
Young, T P, Gibbons, W and McCarroll, D. 2002. Geology of the country around Pwllheli. Memoir of the British Geological Survey, Sheet 134 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used: