Re-assessment of the archaeological potential of continental shelves

The Re-assessment of the archaeological potential of continental shelves project is funded through the Aggregates Levy Sustainability Fund as disbursed by English Heritage. The project assessed the current state of our knowledge and the archaeological potential of marine landscapes for both pre-historic and historic periods on a global basis. The specific geographical areas of interest to this study are the continental shelves which can be defined as the submerged parts of the continental margin, which slope very gently seawards, from the coastal zone (> 0 m depth) to the shelf break (c. 100 - 250 m water depth). Wide (10's - 100's km's) continental shelves are typically associated with passive margins (tectonically benign) which are relatively shallow (e.g. the east coast of North America). Narrow (km's) shelves usually denote active tectonism (e.g. the west coast of South America). In general these latter shelves are also deeper and steeper. On a global average, the shelf is c. 78 km wide, with an average depth of the shelf break being c.135 m. These large scale features aside, the morphology and sedimentology of individual continental shelves is dictated by the complex interplay of both modern and geo-historical factors, including: global and regional fluctuations in sea-level; variability in sediment input rates and sources; and finally modes and rates of sediment transport. Inevitably, these processes not only affect the geological variability of shelves but also play a major role in determining their archaeological potential.