The BGS Lexicon of Named Rock Units — Result Details

Hopton Agglomerate

Computer Code: HOAG Preferred Map Code: notEntered
Status Code: Index Level
Age range: Asbian Substage (CR) — Brigantian Substage (CX)
Lithological Description: Volcanic breccia composed of small lapilli and subangular blocks of dolerite and basalt to 0.6m across.
Definition of Lower Boundary: Intrusive igneous body with transgressive contacts with limestones of the Bee Low Limestone Formation to the north and east.
Definition of Upper Boundary: Overlain unconformably by mudstones of the Millstone Grit Group, whoch crop out to the south and west of the volcanic neck.
Thickness: Not known.
Geographical Limits: Volcanic neck, at Hopton, near Wirksworth, Derbyshire.
Parent Unit: Peak Limestone Group (PKLM)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  Hopton. 
Frost, D V and Smart, J G O, 1979. Geology of the country around Derby. Memoir of the Geological Survey of Great Britain, Sheet 125 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used: