| Computer Code: |
RDT |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Asbian Substage (CR)
— Asbian Substage (CR) |
| Lithological Description: |
A banded tuff with lapilli, including vesicles infilled with analcite. |
| Definition of Lower Boundary: |
Not seen, but defined as the transition from tuffs of the Ravensdale Tuff Member to underlying limestones of the Bee Low Limestone Member. |
| Definition of Upper Boundary: |
Not seen, but defined as the transition from tuffs of the Ravensdale Tuff Member to overlying limestones of the Bee Low Limestone Member. |
| Thickness: |
Up to 20 m thick. |
| Geographical Limits: |
Restricted to the lower part of Cressbrook Dale (SK 17 74), in the northern part of the Peak District inlier. |
| Parent Unit: |
Bee Low Limestone Formation (BLL)
|
| Previous Name(s): |
Ravensdale Tuff [Obsolete Name and Code: Use RDT]
(-4858)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Stream section near Ravensdale Cottages shows 2.44 m of banded tuff with lapilli. Aitkenhead et al., 1985. |
| Reference(s): |
| Aitkenhead, N, Chisholm, J I, and Stevenson, I P. 1985. Geology of the country around Buxton, Leek and Bakewell. Memoir of the British Geological Survey, England and Wales Sheet 111. |
| Arnold-Bemrose, H. 1894. On the microscopical structure of the Carboniferous dolerites and tuffs of Derbyshire. Quarterly Journal of the Geological Society of London, Vol. 50, 603-644. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E111
|
