Rock Edge and Magdalen Quarries
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These pages do not provide any risk assessments. Be aware of your surroundings at all times in the field and do not undertake excursions unless you are comfortable with the risks associated with going into the field. Be mindful of both your safety and the safety of those around you if you choose to undertake any excursions.
These pages do not provide any risk assessments. Be aware of your surroundings at all times in the field and do not undertake excursions unless you are comfortable with the risks associated with going into the field. Be mindful of both your safety and the safety of those around you if you choose to undertake any excursions.
Overview
Situated within old quarries in Headington, Rock Edge and Magdalen Quarries cut through Upper Jurassic limestones of the Corallian Group [1],[2],[3]. Both sites are located approximately 2.2 miles E of the Department. Rock Edge Quarry was relatively easy to find, however Magdalen Quarry is a bit more hidden. Access around Rock Edge was via paths; there was just one outcrop at Magdalen Quarry.Both of these sites are SSSIs; damaging the bedrock is prohibited.
Outcrops
Outcrops were in the form of quarry faces, which were up to 2-3 m high at Rock Edge and around 4 m high at Magdalen Quarry (when I went, it was not possible to get close to the only face present due to vegetation).
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Geology
Coral Rag (rubbly coral reef material) of the Wheatley Limestone Member is exposed at both sites [1],[4], and may represent detrital/fragmentary deposits that flanked or filled in spaces between coral reefs [5],[4]. This Coral Rag tends to be highly porous (with some secondary porosity developed during meteoric diagenesis/dissolution), and often weathers inwards. At Rock Edge, massive corals representing a patch reef are preserved in situ, with the branching coral fragments believed to have been transported over [2],[5].At both sites (though more obvious at Magdalen Quarry), more resistant/indurated limestones are also present, and may represent "background" deposition under calmer shelfal environments in the Oxford Shallows region [2],[3],[5].
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Of the corals, transported Thecosmilia corals were most commonly observed, with Isastraea also being observed. Bivalves were also common. Crinoids fragments and echinoid spines have also been observed by the author in the past, but appear to be quite rare.
See Also
Rock Edge
- https://www.headington.org.uk/events/outdoors/OGT_RockEdge.pdf
- http://www.headington.org.uk/history/quarries/rock_edge.html
- https://www.oxford.gov.uk/directory_record/905/rock_edge_nature_reserve
Magdalen Quarry
- https://www.headington.org.uk/events/outdoors/OGT_Magdalen Quarry.pdf
- https://www.oxford.gov.uk/directory_record/897/magdalen_quarry
- http://www.headington.org.uk/history/quarries/magdalen_pit.html
References
- British Geological Survey (2023). Geology of Britain Viewer, http://mapapps.bgs.ac.uk/geologyofbritain/home.html
- Oxfordshire Geology Trust. (2017). Rock Edge (Cross Roads) Quarry, Headington. https://www.headington.org.uk/events/outdoors/OGT_RockEdge.pdf
- Oxfordshire Geology Trust. (2017). Magdalen (Workhouse) Quarry, Headington. https://www.headington.org.uk/events/outdoors/OGT_Magdalen Quarry.pdf
- Arkell, W. J. (1935). On the Nature, Origin, and Climatic Significance of the Coral Reefs in the Vicinity of Oxford. Quarterly Journal of the Geological Society, 91(1–4), 77. https://doi.org/10.1144/GSL.JGS.1935.091.01-04.04
- de Wet, C. B. (1987). Deposition and diagenesis in an extensional basin: The Corallian Formation (Jurassic) near Oxford, England. Geological Society Special Publication, 36(36), 339–353. https://doi.org/10.1144/GSL.SP.1987.036.01.24