Winchester-East Meon Anticline

The Winchester-East Meon Anticline is one of a series of parallel east-west trending folds in the Cretaceous chalk of Hampshire. It lies at the western end of the South Downs, immediately to the north of the Hampshire Basin and south-east of Salisbury Plain.

The fold is around 35 kilometres (22 mi) long, running from north of Michelmersh near the River Test to East Meon in the valley of the River Meon. In the Winchester area the core of the anticline has been eroded to expose the older Cenomanian Zig Zag Chalk formation in Chilcomb and Bar End (the 'Lower chalk'). This is surrounded by progressively younger rings of the Turonian Holywell Nodular Chalk and New Pit Chalk Formation (the 'Middle chalk') and the Coniacian Lewes Nodular Chalk and Santonian Seaford Chalk Formation ('Upper chalk'). This results in a near-complete ring of inward-facing chalk scarp slopes including Magdalen (Morn) Hill to the north, Chilcomb Down, Cheesefoot Head and Telegraph Hill to the east, Deacon Hill, Twyford Down and St. Catherine's Hill to the south. To the west, cut off by the valley of the Itchen are Compton Down and Oliver's Battery.

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