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
Indian River (Manistique River tributary) Indian River (Manistique River tributary) Indian River is a tributary of the Manistique River on the Upper Peninsula of Michigan in the United States. It rises out of Hovey Lake at on Hiawatha National Forest land in Alger County and flows south and east through a lake district and on through Schoolcraft County. The river flows into the 8,659 acre (35 km²) Indian Lake at and flows out at . It then flows east and south about 2.5 miles where it merges with the Manistique River, which then flows through Manistique and into Lake Michigan at . Major tributaries include