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The BGS Lexicon of Named Rock Units — Result Details

Caldecote Volcanic Formation

Computer Code: CAV Preferred Map Code: CaV
Status Code: Full
Age range: Ediacaran Period (AD) — Ediacaran Period (AD)
Lithological Description: Grey, massive, feldspar and quartz crystal-lapilli tuff with subordinate angular to subrounded lithic blocks. Intercalations of grey to green, fine, well-laminated to massive tuffaceous mudstone, siltstone and sandstone.
Definition of Lower Boundary: Not seen.
Definition of Upper Boundary: Unconformity surface. Overlain by Lower Cambrian beds of the Hartshill Sandstone Formation or by Triassic sandstone and breccia.
Thickness: 130m minimum thickness in general area. 20m minimum in type section.
Geographical Limits: Extends from Nuneaton north-westwards to just south of Atherton Road (SP 3510 9266-3282 9509).
Parent Unit: Charnian Supergroup (CHA)
Previous Name(s): Caldecote Volcanic Series (-751)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  The upper northern level of Boons Quarry, 50m south of Grange Farm. 
Reference(s):
Lapworth, C, Watts, W W and Harrison, W J, 1898. Sketch of the geology of the Birmingham district. Proceedings of the Geologists' Association of London, Vol.15, p.313-389. 
Brasier, M D, Hewitt, R A and Brasier, C J, 1978. On the late Precambrian - Early Cambrian Hartshill Formation of Warwickshire. Geological Magazine, Vol.115/1, p.21-36. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E169