Chenier
Encyclopedia
Chenier or Chénier is a sandy or shelly beach ridge
that is part of a strand plain
, called a “chenier plain,” consisting of cheniers separated by intervening mud-flat deposits with marsh and swamp vegetation. Cheniers are typically 1 to 6 m high, tens of km long, hundreds of metres wide, and often wooded. Chenier plains can be tens of km wide. Cheniers and associated chenier plains are associated with shorelines characterized by generally low wave energy, low gradient, muddy shorelines, and abundant sediment supply. The name is derived from the French word for wood, “chêne,” meaning oak, which grows on chenier ridges within southwest Louisiana.
Cheniers made primarily of shells of the Colorado Delta clam are found in the tidal flats of the Colorado River Delta
in northeastern Baja California
, Mexico
, as well as in Essex, England. In Essex, Ground-truthing data demonstrate that the radar profiles accurately delineate the subsurface stratigraphy and sedimentary structure of the cheniers. Interpretation of the radar stratigraphy taken from the radar reflection profiles allows various deposits to be identified. These have resulted from overwashing, overtopping, sedimentation across the whole of a seaward dipping beachface or berm ridge welding onto the upper beachface. Each chenier is characterised by a different spatial arrangement of these four basic depositional units.
The Louisiana Chenier Plain, extending roughly from Sabine Lake
to Vermilion Bay
along the Gulf Coast, serves critical ecosystem functions, particularly as a wildlife habitat and stopover for migrating birds. As the region was settled, the cheniers were developed preferentially, owing to protection from flooding afforded by the higher elevation. Examples of communities situated on such ridges in the Chenier Plain include Grand Chenier in Cameron Parish and the former settlement of Cheniere Caminada adjacent to Grand Isle
, south of New Orleans. The ridges, however, offer insufficient protection from storm surges, thus Cheniere Caminada was completely destroyed by a hurricane in 1893, and Grand Chenier has been devastated by several powerful storms, including Hurricane Audrey
, Hurricane Rita
, and Hurricane Ike
.
Beach ridge
A beach ridge is a wave-swept or wave-deposited ridge running parallel to a shoreline. It is commonly composed of sand as well as sediment worked from underlying beach material. The movement of sediment by wave action is called littoral transport. Movement of material parallel to the shoreline is...
that is part of a strand plain
Strand plain
A strand plain or strandplain is a broad belt of sand along a shoreline with a surface exhibiting well-defined parallel or semi-parallel sand ridges separated by shallow swales. A strandplain differs from a barrier island in that it lacks either the lagoons or tidales marsh that separate a...
, called a “chenier plain,” consisting of cheniers separated by intervening mud-flat deposits with marsh and swamp vegetation. Cheniers are typically 1 to 6 m high, tens of km long, hundreds of metres wide, and often wooded. Chenier plains can be tens of km wide. Cheniers and associated chenier plains are associated with shorelines characterized by generally low wave energy, low gradient, muddy shorelines, and abundant sediment supply. The name is derived from the French word for wood, “chêne,” meaning oak, which grows on chenier ridges within southwest Louisiana.
Cheniers made primarily of shells of the Colorado Delta clam are found in the tidal flats of the Colorado River Delta
Colorado River Delta
The Colorado River Delta is the region where the Colorado River flows into the Gulf of California . The delta is part of a larger geologic region called the Salton Trough. Historically, the interaction of the river’s flow and the ocean’s tide created a dynamic environment, supporting freshwater,...
in northeastern Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, as well as in Essex, England. In Essex, Ground-truthing data demonstrate that the radar profiles accurately delineate the subsurface stratigraphy and sedimentary structure of the cheniers. Interpretation of the radar stratigraphy taken from the radar reflection profiles allows various deposits to be identified. These have resulted from overwashing, overtopping, sedimentation across the whole of a seaward dipping beachface or berm ridge welding onto the upper beachface. Each chenier is characterised by a different spatial arrangement of these four basic depositional units.
The Louisiana Chenier Plain, extending roughly from Sabine Lake
Sabine Lake
200px | thumb | Sabine lake as seen from outer space.Sabine Lake is a salt water estuary on the Texas-Louisiana border. The lake, some long and wide, is formed by the confluence of the Neches River and Sabine River. Through its tidal outlet long, Sabine Pass, Sabine Lake drains some of Texas...
to Vermilion Bay
Vermilion Bay
Vermilion Bay is a bay in southern Louisiana in the United States.Vermilion Bay is located in southwestern Iberia Parish and southeastern Vermilion Parish...
along the Gulf Coast, serves critical ecosystem functions, particularly as a wildlife habitat and stopover for migrating birds. As the region was settled, the cheniers were developed preferentially, owing to protection from flooding afforded by the higher elevation. Examples of communities situated on such ridges in the Chenier Plain include Grand Chenier in Cameron Parish and the former settlement of Cheniere Caminada adjacent to Grand Isle
Grand Isle, Louisiana
Grand Isle is a town in Jefferson Parish, Louisiana, located on a barrier island of the same name in the Gulf of Mexico. The island is at the mouth of Barataria Bay where it meets the gulf. As of the 2000 census, the town population was 1,541; during summers, the population sometimes increases to...
, south of New Orleans. The ridges, however, offer insufficient protection from storm surges, thus Cheniere Caminada was completely destroyed by a hurricane in 1893, and Grand Chenier has been devastated by several powerful storms, including Hurricane Audrey
Hurricane Audrey
Hurricane Audrey was the first major hurricane of the 1957 Atlantic hurricane season. Audrey was the only storm to reach Category 4 status in June. A powerful hurricane, Audrey caused catastrophic damage across eastern Texas and western Louisiana. It then affected the South Central United States as...
, Hurricane Rita
Hurricane Rita
Hurricane Rita was the fourth-most intense Atlantic hurricane ever recorded and the most intense tropical cyclone ever observed in the Gulf of Mexico. Rita caused $11.3 billion in damage on the U.S. Gulf Coast in September 2005...
, and Hurricane Ike
Hurricane Ike
Hurricane Ike was the second-costliest hurricane ever to make landfall in the United States, the costliest hurricane ever to impact Cuba and the second most active hurricane to reach the Canadian mainland in the Great Lakes Region after Hurricane Hazel in 1954...
.