| Computer Code: |
NWS |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Emsian Age (DE)
— Emsian Age (DE) |
| Lithological Description: |
The formation consists of red-purple extraformational conglomerates (40.7%) with a wide range of exotic pebbles, red-purple very fine- to very coarse grained sandstones (35.1%), and sandy, coarse-grained siltstones (24.1%), principally arranged in 1 to 10m-thick, fining-upward units, with a few coarsening upward sequences up to 7m thick. |
| Definition of Lower Boundary: |
The lower boundary is a gradational boundary with the underlying Lawrenny Cliff Formation and placed where red-purple beds succeed the green beds of the underlying Lawrenny Cliff Formation. The actual junction is nowhere exposed. |
| Definition of Upper Boundary: |
The boundary is not seen, the Formation being unconformably overlain by strata of the Avon Group (formerlt "Lower Limestone Shales") of Early Carboniferous age. This junction is seen on the shore on the east side of the Carew River [SN 03852 04105] southsoutheast of New Shipping Point. It is a scour surface with up to 2cm relief cut in medium- to coarse grained purple sandstone overlain by a bed of quartz grit up to 4cm thick with shell fragments. |
| Thickness: |
320 to 400+m |
| Geographical Limits: |
The Formation occupies a small area around New Shipping [SN 035 043] in the upper reaches of the Carew River east of Milford Haven, Pembrokeshire. It is present in a small outcrop east of Ford Point [SN 0346 0404]. On the west side of the River Carew, it crops out west of Ford Pill from near Paskeston [SN 028 035] north to Hakin Point [SN 033 043]. It is also present in a small area in the northeast of the Lawrenny peninsula 500m south of Lawrenny [SN 019 066]; in a faulted block on the western shore of Cosheston Pill [SM 982 040] near Waterloo; and in a partially faulted block on the northern shore of Cosheston Pill [SM 996 035] 500m southwest of Cosheston. |
| Parent Unit: |
Cosheston Subgroup (COB)
|
| Previous Name(s): |
Cosheston Subgroup
(COB)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Type section at New Shipping. It exposes about 80% of the formation, in discontinuous low cliffs and rock platforms on the northern shore of the Carew River between New Shipping Point and 200m southsouthwest of New Shipping Farm . The section is mostly a dip or oblique-dip section, the beds dipping 15-55 degrees south or southeast and cut by two faults of unknown sense and throw. Thomas et al, 2006, Figure 19A for a representative 32m portion of the section. |
| Reference(s): |
| Thomas, R G, Williams, B P J, Morrissey, L B, Barclay, W J and Allen, K C. 2005. Enigma variations: the stratigraphy, provenance, palaeoseismicity and depositional history of the Lower Old Red Sandstone Cosheston Group, south Pembrokshire, Wales. Geological Journal, Vol.41, 481-536. |
| Cantrill, T C, Dixon, E E L, Thomas, H H, Jones, O T. 1916. The geology of the South Wales Coalfield, Part XII: the country around Milford. Memoir of the Geological Survey, England and Wales. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
