Conegar Road Cutting
Also within
Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| ST439027 | — | Favourable | 0.15 | 2015-03-11 |
Geology & landscape
Rock Type: Limestone
Description
Description The site at Conegar Road Cutting comprises a 175 metre long road section located immediately north of Broadwindsor. The steep east and west facing road sides expose a nationally important sequence through the upper parts of the Bridport Sands and the Lower Inferior Oolite and clearly demonstrate the stratigraphical relationships between these lithologies. The total thickness of the succession is approximately 20 metres. The Upper Bridport Sands comprise a 15 metre thick sequence of fossiliferous yellow sangs and sand burrs which pass up into thinner sandstones and marls the Rusty and Brachiopod Beds. Several species of ammonites Leioceras spp., Pleydellia sp. and Canavarella aff. toma have been recorded from these sediments along with common brachiopods Terebratula whaddonensis, Rhynchonella cynocephala and belemnites indicating an early Aalenian Leioceras opalinum Zone age. Overlying rubbly, calcareous sandstones are assigned to the Scissum Beds and above these are thin limestones termed the Ancolioceras and Murchisonae Beds. These sediments contain a bivalve and ammonite fauna, including Ludwigia spp., which is typical of the basal part of the Ludwigia murchisonae Zone of mid Aalenian age. Above a major discontinuity surface, the top of the succession is marked by a thick limestone which yields perisphinctid ammonites indicating a late Bajocian Parkinsonia bomfordi Subzone age.