| 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
|
| Stratotypes: |
| Type Area |
Hopton. |
| Reference(s): |
| 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: |
|
E125
|
