The BGS Lexicon of Named Rock Units — Result Details

Ladder Hills Formation

Computer Code: LAHI Preferred Map Code: SYMB
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Micaceous and feldspathic psammites, semipelites and thin bands of pelite, the latter locally graphitic. Typically flaggy and commonly graded. Tuffaceous and rare metavolcanic beds. 'Boulder Bed' lithology with associated lenticular dolomite beds. Calc-silicate lenses in part. Quartzite bands.
Definition of Lower Boundary: Rapid transition from semipelite and pelite of the Glenfiddich Pelite Formation to micaceous and feldspathic psammite-dominated sequence.
Definition of Upper Boundary: Grades laterally and upwards into a semipelite/dark pelite/limestone sequence in Nochty Water-Upper Glenbuchat area. Elsewhere overlain by feldspathic quartzite and orthoquartzite of the Kymah Quartzite Formation.
Thickness: 0 to 1000m+. Probable duplication by folding in the Ladder Hills area.
Geographical Limits: Main development in the Ladder Hills. Thins northwards to flanks of Scaut Hill. Thins southwards to Donside (Carn Oighreag).
Parent Unit: Islay Subgroup (DBIS)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  Ladderfoot-Dun Muir. Section up the Ladder Burn. 
Reference Section  Allt an t-Sluichd Mhoir stream section, in its upper part. 
Reference Section  Upper part of Caochan Crom. 
Memoir of the British Geological Survey, Sheet 75, in preparation. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: