Bugle Quarry SSSI

Bucks County Council administration area: Aylesbury Vale District Council

Grid reference: SP 793 121

Area of site: 0.08 ha (c. 30m x 25 m x 6 m high)

Access, location and parking: Permission is required from the owner. (The quarry is unsafe to use which has upset the owner. In the first instance contact Natural England at the Newbury Office to assess the current ‘state of play’ for visits). Parking is near the entrance to the farm gates or at various locations along the A418.

Site description: Disused pit, originally infilled by the late 1950s and re-opened in 1984. The excavation is surrounded by a strong retaining fence within a horse grazing area.

Geological interpretation: The geological SSSI notification is for Portlandian (Jurassic) stratigraphy and for vertebrate palaeontology (reptilian). The locality contains an important sequence of topmost marine Portland and basal, partly non-marine, Purbeck Beds. It is historically important featuring in the geological literature for over 150 years with accounts on stratigraphy, fossils and palaeoecology. There are important ostracod faunas which typify the Portland-Purbeck junctions and the environmental changes from sea to land. The vertebrates recorded from this site include several sauropod (dinosaur) teeth from the only known remains of Pelorosaurus sp. of Portlandian age in Europe . Teeth from the carnosaur Megalosaurus sp. have also been found at the Bugle Pit again the only known location from the Portlandian in Britain .

In addition, the RIGS interest is large as the boundary between the Portland Creamy Limestones and the Purbeck Limestone Formation is not seen elsewhere in the county at present. The site presents a good educational opportunity to see directly some of the evidence for changes in sea-level and the brackish and freshwater deposits of the Jurassic Purbeck. It is useful therefore for students or people with an interest in palaeoenvironments, sea-level changes, palaeoecology, stratigraphy or local geological history. Although the Creamy Limestones can be seen in the walls of buildings in nearby Hartwell, Stone and Dinton, amongst others, it is educationally desirable to have an in situ section of the same rocks. (This is the only way to study stratigraphy!)

Current and potential educational  use (geology, ecology, archaeology, industrial archaeology): Current use is not made of the site due to the dangerous and inaccessible condition. Potentially it is a very interesting and essential geological site for the reasons outlined above.

Conservation interest: To maintain the integrity and exposure of the Portland and Purbeck limestones within the pit.

Threats to site (present and future): natural processes such as further vegetation growth and rock falls are the major risk as infill is prohibited under the SSSI status.

Constraints (basic risk assessment): Currently unsafe to access due to steps degrading and access blocked by thick vegetation growth and fallen rubble. If steps were re-cut they would require maintenance from time to time.

Reference list/bibliography:

Barker, D. 1966. British Jurassic and Cretaceous Ostracoda. Bull. Brit. Mus. (Nat. Hist.) Geol., 11, 459-488.

Davies, A. M. and Wilson, V. 1949. Field Meeting in the north Chiltern Hills and Aylesbury District. Proceedings of the Geologists’ Association, 60, 219-221.

Hudleston, W. H. 1887. Excursion to Aylesbury. Proceedings of the Geologists’ Association, 10, 166-172.

Lydekker, R. 1893. On two dinosaurian teeth from Aylesbury. Quart. J. Geol. Soc. London., 49, 556-568.

Merrett, A. 1924. Ostracods found in the Purbeck Beds of the Vale of Aylesbury. Geol. Mag., 61, 233-238.

Radley, J. D. 1991. Palaeoecology and deposition of Portlandian (Upper Jurassic) strata at the Bugle Pit, Hartwell, Buckinghamshire. Proceedings of the Geologists’ Association 102(4), 241-249.

Sumbler, M. G. 1990. Geological notes and local details for 1:10000 sheets SP 71 SE (Stone). Brit. Geol. Surv. Techinical Report WA/89/67.

Wimbledon , W. A. 1980. Portlandian correlation chart. In: Cope, C. J. W. (ed.) A correlation of Jurassic rocks in the British Isles . Part 2: Middle and Upper Jurassic. Spec. Rep. Geol. Soc. Lond., 15, 85-93.

Woodward, A. S. 1895. Note on megalosaurian teeth discovered by Mr J. Alstone in the Portlandian of Aylesbury. Proceedings of the Geologists’ Association, 14, 31-32.

Woodward, H. B. 1895 The Jurassic rocks of Great Britain , 5. The Middle and Upper Oolitic rocks of England ( Yorkshire excepted) Mem. Geol. Survey of GB.