干旱区生态环境知识资源中心

A multidisciplinary colligation including new data and analysis of the evidence for the climates of southern Britain during c. 140 Ma. to c. 120 Ma BP (Berriasian-Barremian - ? earliest Aptian). The climate was at first hot, semi-arid and ’Mediterranean’ (rather than ’monsoonal’) in type, probably with seasonally opposed winds (E/W). An irregular long-term trend of increasing rainfall in the moister seasons is evident. This was probably associated with establishment of predominant westerlies during the Jurassic-Cretaceous transition and slightly lower average annual temperatures thereafter until Barremian times. Causes proposed are frequent changes in the regional climatic system due to tectonically induced adjustments of relief under the special conditions of the semienclosed Purbeck-Wealden archipelago and increasing proximity of the widening Protoatlantic sea.