The BGS Lexicon of Named Rock Units — Result Details
Auch Gleann Psammite Formation
Computer Code: | AUGL | Preferred Map Code: | AUGL |
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Status Code: | Full | ||
Age range: | Cryogenian Period (AC) — Cryogenian Period (AC) | ||
Lithological Description: | Interbedded pink quartzofeldspathic psammite and grey micaceous grey psammite. Parallel bedded psammite layers 10-20cm thick develop plane parallel internal lamination defined by alternations of more micaceous and quartzofeldspathic layers at a mm scale. Similar scale but undulose bedded forms also present with rare preservation of hummocky cross stratification. Subsidiary 50-100cm-thick massive beds may have a lenticular form and may be indicative of channel or sand-wave macroforms. Semipelite to pelite comprises a very minor part of the Formation but forms in layers up to 15m thick. | ||
Definition of Lower Boundary: | Not seen. | ||
Definition of Upper Boundary: | Abrupt change to white weathering pinkish-brown quartzose psammite and quartzite of the succeeding Beinn a' Chaisteil Formation. | ||
Thickness: | >1000m. | ||
Geographical Limits: | Includes all of the Grampian Group psammite rocks which extend across the northern parts of 1:50k sheets 46W (Crianlarich) and 46E (Killin). | ||
Parent Unit: | Glen Spean Subgroup (GRGS) | ||
Previous Name(s): | Moine [Obsolete Name and Code: Use AUGL]
(-3810)
Grampian Group (Undivided) (-660) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Reference Section | Allt Coralan (Glen Coralan), tributary of Auch Gleann, upstream from railway viaduct. Details will be included in Sheet Description for Sheet 46W (Crianlarich);Presently in draft BGS internal report: Leslie et al. Progress Report on Geology of the Tyndrum area, 2003. 1:50k Sheet 46W (Crianlarich). | ||
Reference(s): | |||
In preparation. BGS Sheet Description for Sheet 46W (Crianlarich) and 46E (Killin). | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
none recorded or not applicable |