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Outline

Chapter 2 Time and Place : chronology and landscape by

2012

Abstract

From the north the High Speed 1 (HS1) route extends from the Ebbsfleet Valley at Springhead south-eastwards across the dip slope of the North Downs (see Fig. 2.1 below). The first 15km of the route south-east of Fawkham Junction to the River Medway is, apart from Scalers Hill, predominantly through Upper Chalk overlain in the deeper cuts by Thanet Beds and/or Head. East of Scalers Hill there are extensive solution features in the top of the chalk. Scalers Hill is an outcrop of the Lower London Tertiaries consisting of Harwich Formation/Blackheath Beds sands and gravels over Woolwich and Reading Beds clay (BGS 2010). After crossing the River Medway on a 1.3km bridge and viaduct the HS1 runs up the Nashenden Valley mainly through Upper Chalk and then into the 3.2km North Downs Tunnel under Blue Bell Hill. The crest of the North Downs escarpment, overlooking the Weald, reaches a height of c 200m OD and is frequently capped by surface deposits of Clay-with-Flints or Tertiary deposits. E...