Figure 44. Evolution of Nearshore Basins. The upper panel depicts the seafloor shortly after glaciers have left, and the ocean level is 80 m deeper than today. Glacial-marine mud mantles most of the seafloor. In the middle panel, the seafloor has isostatically rebounded following melting of the ice, and the former seafloor is up to 60 m above the shoreline at that time. Some of the glacial sediment was eroded by streams during emergence, and forest covered much of the area then. In the lower panel, sea level has risen to its present position and drowned the Nearshore Basins. During submergence, erosive processes, such as the bluff erosion occurring along the shoreline today, removed mud from some areas and deposited modern, Holocene mud in deeper places. Natural gas is forming in some thick mud deposits, possibly the site of former lakes, bogs, and coastal wetlands.
Last updated on October 6, 2005