The BGS Lexicon of Named Rock Units — Result Details
Glyn Gower Siltstones Member
Computer Code: | GYG | Preferred Map Code: | GyG |
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Status Code: | Full | ||
Age range: | Soudleyan Substage (OY) — Soudleyan Substage (OY) | ||
Lithological Description: | Laminated siltstones and fine-grained sandstones with subordinate mudstones and rare thin tuffs. | ||
Definition of Lower Boundary: | Conformable and gradational with mudstones of the Ceiswyn Formation, generally taken at the top of the Cefn Gwyn Tuff where the latter is present. | ||
Definition of Upper Boundary: | Conformable and gradational with mudstones of the Ceiswyn Formation, but generally taken at the base of the overlying Frondderw Tuff, where the latter is present. | ||
Thickness: | 130m to 150m. | ||
Geographical Limits: | Corwen and Bala districts. | ||
Parent Unit: | Ceiswyn Formation (CSW) | ||
Previous Name(s): | Glyn Gower Siltstones [Obsolete Code: Use GYG]
(GLS)
Glyn Gower Formation [Obsolete Name and Code: Use GYG] (-2838) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Partial Type Section | Hill top, northeast of the Glyn Gower valley. Bassett, D A, Whittington, H B and Williams, A. 1966 | ||
Reference Section | Lower reaches of the Glyn Gower valley, 1km southeast of Llangower village. Elles, 1922. | ||
Reference(s): | |||
Elles, G L. 1922. The Bala country: its structure and rock succession. Quarterly Journal of the Geological Society of London, Vol.78, 132-175. | |||
Bessett, D A, Whittington, H B and Williams, A. 1966. The stratigraphy of the Bala district, Merionethshire. Quarterly Journal of the Geological Society, London, Vol.122, 219-271. | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
E120 E136 |