The BGS Lexicon of Named Rock Units — Result Details

Boon's Member

Computer Code: BOO Preferred Map Code: Boo
Status Code: Full
Age range: Comley Series (EC) — Comley Series (EC)
Lithological Description: Red massive granulestone and boulder-breccia beds at base, passing up to red lithic sandstone with thin breccia layers and capped by grey massive sandstone with minor siltstone. Sandstone and granulestone are massive, with sporadic parallel stratification and normal or inverse grading. Boulder breccias contain large (to 2m) rounded clasts detached from underlying weathered Precambrian rocks.
Definition of Lower Boundary: Sharp unconformable contact of granulestone on spheroidally-weathered Precambrian tuffs of the Caldecote Volcanic Formation.
Definition of Upper Boundary: Conformable contact with Park Hill Member. The top is taken at the surface of the bed immediately beneath the first sandstone to show significant current bedding.
Thickness: Possibly between 20 and 40m in general range. In partial type sections: a)3.0mb) 7.2m minimum c) 6.7m.
Geographical Limits: North and south-east sectors of Boons Quarry south of Grange Farm.
Parent Unit: Hartshill Sandstone Formation (CQ)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Partial Type Section  a) Upper level of Boons Quarry, 50 metres south-south-west of Grange Farm. (Lower beds) 
Partial Type Section  c) Lower level at south corner of Boons Quarry, 300 metres south-south-east of Grange Farm. (Upper beds) 
Partial Type Section  b) Lower level of Boons Quarry, 320 metres south-south-east of Grange Farm. (Middle beds) 
Carney, J N. 1992. Geology and structure of the Lower Cambrian Hartshill Sandstone Formation: information from quarries north-west of Nuneaton. British Geological Survey Technical Report WA/92/08. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: