| Computer Code: |
DHBT |
Preferred Map Code: |
DHBT |
| Status Code: |
Full |
| Age range: |
Rawtheyan Stage (OW)
— Rawtheyan Stage (OW) |
| Lithological Description: |
Siltstone and mudstone with interbedded units of lithic crystal tuff, probably of silicic composition |
| Definition of Lower Boundary: |
Taken at the base of the lowest bed of volcaniclastic rock overlying calcareous siltstone and argillaceous limestones of the Norber Formation |
| Definition of Upper Boundary: |
Taken at the top of the last bed of tuff where it is overlain by siltstone and mudstone within the main part of the Sowerthwaite Formation |
| Thickness: |
Up to 40m |
| Geographical Limits: |
Restricted to the Austwick area of N Yorkshire |
| Parent Unit: |
Sowerthwaite Formation (SOW)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Austwick Beck at Dam House Bridge, North Yorkshire. Arthurton et al., 1988. |
| Reference(s): |
| Arthurton, R S, Johnson, E W, and Mundy, D J C. 1988. Geology of the country around Settle. Memoir of the British Geological Survey, Sheet 60 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E060
|
