Geoarchaeological survey and palaeoenvironmental analyses were conducted in the floodplain of the river Ure to the north of the Roman town of Isurium Brigantum (Aldborough, North Yorkshire) as part of a complementary campaign of geophysical survey and excavations (2018–2024). This involved an intensive coring survey to understand the development of the valley and the environmental context of the settlement. A large palaeochannel was discovered south of the present day canalised river which was sampled for palynological, physical and geochemical analyses, with portable OSL determinations, and radiocarbon and OSL dating. The sedimentological analysis revealed riverine activity from the Late Mesolithic period (ca. 4600–4300 BC) through Roman and Medieval times. A 6 metre deep, multi-process fluvial system was present with evidence of active and low/slow flow phases in earlier prehistoric times, followed by prolonged periods of overbank alluviation from the Iron Age onwards, and particularly coincident with the Roman occupation of Isurium. By the Roman period, there was a shallow channel in a wide floodplain, slowly filling with alluvium, necessitating the construction of a lengthy road-bridge structure, before shifting northwards. This was set against progressive woodland diminution and extensive human impact during the late prehistoric, Roman and early historic periods.
French et al. (Tue,) studied this question.