Sarsens and puddingstones have long been recognised as varieties of silcrete and were, until recently, considered to have formed under hot sub-tropical or tropical climates in tectonically stable, low relief landscapes during the early Palaeogene. This paper provides a summary of the major advances in silcrete research since the most recent review of sarsen development and focuses upon models of silcrete genesis derived from studies in France, Australia and the Kalahari region of southern Africa. These models include silcretes which formed within soil profiles by pedogenic processes (pedogenic silcretes), those which formed in zones of groundwater outflow or water table fluctuation in association with drainage-lines or in lacustrine settings (groundwater or drainage-line silcretes), and more complex cases where silcretes developed through the interaction of more than one set of processes through time (multiphase and intergrade silcretes). Each of these models is subsequently placed within a landscape context through consideration of a series of case studies. The implications of this recent research for the interpretation of UK sarsens and puddingstones are discussed. The importance of identifying the mode or modes of origin of any silicified remnant materials before drawing any conclusions concerning their age, extent and possible palaeoenvironmental significance is stressed.
|Number of pages||16|
|Journal||Proceedings of the Geologists' Association|
|Publication status||Published - 1 Jan 1998|