| Computer Code: |
SCLA |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Arundian Substage (CJ)
— Arundian Substage (CJ) |
| Lithological Description: |
A typically fine grained, chocolate-brown, massive and highly amygdaloidal olivine basalt, with imperfect pillow structures and red oolitic limestone fragments in all stages of alteration and assimilation, which in places appear to occupy spaces between pillows. In the centre of the member, cindery lava is mixed with broken limestone fragments. Calcite veins are common throughout. |
| Definition of Lower Boundary: |
The base is irregular and channelled up to 1.2 m into the underlying limestone of the High Tor Limestone Formation. |
| Definition of Upper Boundary: |
A sharp boundary forms the upper boundary between basalt and overlying reddish-fawn, dolomitised limestone of the High Tor Limestone Formation, containing tuffaceous debris in the bottom 1.5m, decreasing upwards from the base. |
| Thickness: |
15 m thick. |
| Geographical Limits: |
Spring Cove, north Somerset. |
| Parent Unit: |
High Tor Limestone Formation (HTL)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Section in a coastal cliff at Spring Cove, north Somerset, where the entire thickness can be seen, as composed from several loggers' notes. Whittaker and Green, 1983. |
| Reference(s): |
| Whittaker A and Green G W. 1983. Geology of the country around Weston-super-Mare. Memoir of the Geological Survey, England and Wales, Sheet 279 with parts of sheets 263 and 295. |
| Boulton W. 1904. On the igneous rocks at Spring Cove, near Weston-Super-Mare. Quarterly Journal of the Geological Society of London, 60, 158-169. |
| Reynolds S. 1917. Further work on the igneous rocks associated with the Carboniferous Limestone of the Bristol District. Quarterly Journal of the Geological Society of London, 72, 23-42. |
| Speedyman D L. 1977. Volcanic rocks of the Bristol Region. In: Geological Excursions in the Bristol district (Editor: Savage R J G.), pp. 47-54, University of Bristol. |
| Waters, C N. 2003. Carboniferous and Permian igneous rocks of central England and the Welsh Borderland. In: Carboniferous and Permian Igneous Rocks of Great Britain North of the Variscan Front. (editors Stephenson D, Loughlin S C, Millward D, Waters C N, and Williamson I T.), pp. 279-316, Geological Conservation Review Series, No. 27 (JNCC). |
| Jeffreys, D H, 1979. Sedimentology of the Dinantian Volcaniclastic carbonate rocks of Middle Hope and Spring Cove, Weston-Super-Mare, University of Reading, Unpublished M.Sc Thesis. |
| Strahan A, and Cantrill T. 1912. The Geology of the South Wales Coalfield, Part III. The country around Cardiff. Memoir of the Geological Survey of Great Britain. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E279
|
