|The Parish of Radley (National Grid Reference SU 525 990) is an area measuring approximately 3km east-to-west by 4.5km north-to-south in the Thames valley just south of Oxford. The topography is fairly uniform with the land sloping from 93m above mean sea level in the northwest (Sugworth) to 52 metres above msl along the River Thames, which marks the eastern and southern boundaries of the parish.
Radley lies on the narrow belt of 140 million year old Kimmeridge Clay, which, in southern England, extends from Aylesbury through Abingdon and Swindon. This belt marks the southern edge of the Upper Jurassic rocks which extend in a broad band across the SE midlands. At Radley, this is overlaid with alluvium with first terrace sand and gravel deposits to the south, which have been extensively worked over many years; and older second terrace deposits to the north. However, in other parts of Oxfordshire, as well as in Wiltshire and Dorset, Upper Jurassic clay beds, in the course of being mined for the production of bricks, have proved to be a rich source of dinosaur remains.
Across the river, to the south of Radley, in the parish of Culham, the underlying rocks are of the more recent Cretaceous period.
Even up to the present day, the geology of southern Radley is being altered by man through the extraction of sand and gravel and the infilling of the pits with pulverised fuel ash (PFA) from Didcot Power Station.