Disused quarry, exposure site, Local Nature Reserve.
Kirtlington Quarry SSSI, Oxfordshire exposes limestones, marls and clays which were deposited during the Middle Jurassic, about 172 million years ago. The fossils in these rocks indicate that they were deposited in a warm shallow sea, possibly in lagoons behind a series of islands. Evidence for the presence of nearby land is provided by the presence of fossil wood, freshwater algae and crustaceans, disarticulated dinosaur skeletons and very rare mammal fossils. At certain levels in the quarry, there are indications that the sea floor had occasionally emerged to become land.
The quarry is especially important because it has yielded a diverse fauna of Mesozoic mammals from one particular bed. These fossils are extremely rare and are important for understanding the origins and early evolution of mammals. The beds which yielded the mammals have also produced a variety of other vertebrates, including fishes and crocodiles, but more importantly, early frogs, salamanders and lizards.
Over a long period, many of the exposures in the quarry had become overgrown, while others had suffered a talus build-up as a result of fossil collecting. In addition, the site was being used for motor-cycle scrambling and other activities, which were detrimental to the interest. The owners of Kirtlington Quarry, Blue Circle Cement, leased it to Cherwell District Council, who, with a range of partners, designed and developed on-site interpretation, improved access by introducing steps and observation platforms and restricted vehicular access. Kirtlington Quarry was declared a Local Nature Reserve.