The importance of water in aeolian systems : an example from the Sherwood Sandstone of the West Midlands

The preserved sedimentary expression within dry-land environments was traditionally thought to be the product of either extensive ephemeral (short-lived) fluvial sedimentation or dominated by windblown migrating duneforms. However, within the last few decades increasing evidence has shown that few dry-land environments remain solely the remit of either aeolian or fluvial process but commonly a mix of both. A number of interactions between these depositional mediums are increasingly being identified within dry-land environments and these have been shown to occur on a variety of scales, as either symbiotic or competitive in nature. Examples of the interactions between fluvial and aeolian facies are observed within the Triassic aged Sherwood Sandstone Group, of western and central parts of England (in and around the Cheshire Basin). On a national scale the Sherwood Sandstone is primarily of fluvial affinity, with its source situated in modern-day north France. The fluvial system of the Sherwood Sandstone Group flowed in a northerly direction across southern and central England from northern France, covering large portions of the Triassic land surface in eastern and western England (the Midlands) and infilling numerous different basins (Fig. 1). Where the fluvial system entered the Cheshire Basin in western England it interacted with a contemporaneous aeolian dune-field, leading to a number of different styles of system interaction.