Submerged forest


A submerged forest is the in situ remains of trees that lie submerged beneath a bay, sea, ocean, lake, or other body of water. These remains have usually been buried in mud, peat or sand for several thousand years before being uncovered by sea level change and erosion and have been preserved in the compacted sediment by the exclusion of oxygen. A forest can become submerged as the result of a lake or sea level rise that results in a lacustrine or marine transgression and in-place drowning of the forest. A submerged forest that lies beneath a lake can also be formed by the blockage of a river valley by either a landslide or manmade dam.

Examples

Marine submerged forests may be regularly exposed at low tide; examples of these can be found at low tide on the fringes of the submerged landmass known as Doggerland, around the coast of England and the coasts of Wales, the Channel Islands, north-west France and Denmark. In some places, such as Blackpool Sands, Dartmouth, the remains are normally covered by sand and only rarely exposed. During the storms of 1974 and the Winter storms of 2013–14 in the United Kingdom extensive remains of submerged forests were revealed in a number places around the coast of Britain.
As the North American Laurentide Ice Sheet began receding for the last time some 10,000 years ago, water levels in the future Great Lakes were sometimes much lower than at present. Forests once covered the southern end of what is now Lake Huron but as the glaciers melted and waters rose these forests were inundated and drowned. Today their remnants, well preserved logs and stumps, have been discovered in waters over 200 feet deep.
Another submerged forest has been found in Nantucket Sound, off the coast of Massachusetts. and in 2012 a submerged bald cypress forest, which has been dated at around 50,000 years old, was discovered in the Gulf of Mexico off the coast of Alabama.