Mercia Mudstone as a Triassic aeolian desert sediment

It has been suggested that at least parts of the Mercia Mudstone in the English Midlands are closely related to loess, or loess-like sediments. It seems likely that the Mercia Mudstone is an ancient form of parna, the aeolian desert sediment formed in the Australian Quaternary. This is essentially a form of loess having silt-sized particles and an open depositional packing. Loess-like systems tend to collapse when loaded and wetted, and this appears to have occurred in the mudstone. The collapse behaviour of the Mercia Mudstone is probably the strongest indication of a loessic origin. Study of the Mercia may throw some light on the nature of parna - the most characteristic of the Australian loesses.