The Quaternary rivers of the Jurassic Coast region: From the Neogene to the Anthropocene

Abstract

The Jurassic Coast World Heritage Sites (JCWHS) is not only a 95 km long coastline and remarkable Mesozoic geological section, but also a slice through a Quaternary landscape. For the majority of the last two million years this landscape lay in the periglacial zone, just south of a waxing and waning ice margin and just north of an Atlantic inlet which eventually became the English Channel. This paper reviews how the previous landscape inherited from the Cenozoic, was modified through uplift, climatically driven fluvial activity and periglaciation. Much evidence of this Quaternary history can be been today in sections along the JCWHS coast which is cuts through a number of headwater valleys the largest of which are the Exe and Axe. Recent studies, largely funded from the Aggregate Levy Tax, have produced the first independent chronologies for the Exe and Axe valleys and a model of how periglaciation interacted with the layer-cake stratigraphy of the Mesozoic bedrocks of the JCWHS. The Quaternary history of the JCWHS is also preserved in raised beaches on the Isle of Portland, coastal landforms, and in Holocene alluvial sediments associated with human activity and which may constitute part of the putative Anthropocene. An appreciation of the Quaternary history of the JCWHS is also important in understanding modern geological hazards from landslides to flooding.

Geological Heritage of the Anthropocene Epoch—A Conceptual Viewpoint

“…The publications that directly link geoheritage to the Anthropocene remain very few [42][43][44][45][46][47]. Some articles focus on specific issues and others relate two ideas in an occasional manner.…”

“…Pica et al [43] stressed a still limited interest of Anthropocene researchers in urban geomorphological heritage, although the latter provides excellent evidence of characteristic features such as specific deposits of the newlyproposed epoch. Brown et al [44] reviewed the alluvial record of the Jurassic Coast World Heritage Sites and concluded that some landforms and sediments reflect human activity in the Anthropocene and, thus, this globally-ranked geoheritage site can contribute to the knowledge of this interval of the geological time.…”