Kent coastline of Kent is continuously changing, due to tectonic uplift and coastal erosion. Until about 960, the Isle of Thanet was an island, separated by the Wantsum channel, formed around a deposit of chalk; over time, 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 East Grinstead in Sussex and flows eastwards to Maidstone. Here it turns north and breaks through the North Downs at Rochester, then joins the estuary of the River Thames as its final tributary near Sheerness. The Medway is
Genesee River Genesee River The Genesee River is a tributary of Lake Ontario flowing northward through the Twin Tiers of Pennsylvania and New York in the United States. The river provided the original power for the Rochester area's 19th century mills and still provides hydroelectric power for downtown Rochester. The Genesee is the remaining western branch of a preglacial system, with rock layers tilted an average of 40 feet (12 m) per mile, so the river flows across progressively older bedrock as it flows northward. It begins in exposing the Allegheny Plateau's characteristic conglomerates: sandstones and shales in the of the Mississippian