Geology of Kent to uplift, sedimentation, and marine erosion. The Isle of Thanet was till recently (AD 960) an island, formed around a deposit of chalk. The channels silted up with alluvium. Similarly Romney Marsh and Dungeness have been formed by accumulation of alluvium. Kent's principal river, the River Medway, rises near Edenbridge and flows some 25 miles (40 km) eastwards to a point near Maidstone, when it turns north. Here it breaks through the North Downs at Rochester before joining the River Thames as its final tributary near Sheerness. The river is tidal as far as Allington lock, but in earlier times
Worcester, Nashua and Rochester Railroad years later. The Commonwealth of Massachusetts acquired this portion of the right of way; in 2002 it was officially opened as the Nashua River Rail Trail. The one mile of track between Union Station in Nashua and an industrial park was abandoned finally in 1993. The W&N still survives between Ayer and Worcester, operated by Pan Am Railways whereby it is now designated as that railroad's Worcester Main branch. The line sees daily through-freight usage, permitting interchange at Worcester with CSX and Providence & Worcester Railroad. Worcester, Nashua and Rochester Railroad The Worcester, Nashua and Rochester Railroad was a railroad