Sea-Level History and Quaternary Evolution of River Mouth-Associated Beach-Ridge Plains Along the East-Southeast Brazilian Coast: A Summary
Jose M.L. Dominguez, Louis Martin, Abilio C.S.P. Bittencourt, 1987. "Sea-Level History and Quaternary Evolution of River Mouth-Associated Beach-Ridge Plains Along the East-Southeast Brazilian Coast: A Summary", Sea-Level Fluctuation and Coastal Evolution, Dag Nummedal, Orrin H. Pilkey, James D. Howard
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The record of recent sea-level variations for the east-southeast Brazilian coast is characterized by a maximum height of 5 m above present sea level about 5.1 ka. Sea-level fall from that highstand was interrupted by high-frequency sea-level oscillations as large as 2–3 m acting on time scales of no more than 200-300 yrs. This sea-level history had a profound effect on the evolution of sedimentary plains associated with the mouths of the major rivers emptying onto the east-southeast coast of Brazil.
During the 5.1 ka highstand, these plains were drowned and barrier island-lagoonal systems associated with intralagoonal deltas were the dominant environments of deposition. During the subsequent drop in sea level, conditions for the genesis and maintenance of barrier island-lagoonal systems were highly unfavorable. The coastline rapidly prograded, giving origin to regressive sand sheets.
In the Jequitinhonha River beach-ridge plain, the short-term Holocene sea-level rises caused drowning of the river mouth and induced abrupt shifts in the lower river course. In the Doce River beach-ridge plain, these same events resulted in the formation of new barrier island-lagoonal systems as well as reoccupation of old lagoons by the sea. The main sources of sediment for the progradation of the coastline were provided by wave-induced longshore drift of sediments made available through reworking of the inner shelf via falls in sea level.
These data, derived from study of the Brazilian coast, strongly suggest that sea-level history during the Holocene was a dominant factor in controlling styles of sedimentation around the coastlines of the world.
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Sea-Level Fluctuation and Coastal Evolution - This Special Publication is the result of a symposium in honor of W. Armstrong Price held at the first SEPM Midyear Meeting at San Jose, California, on August 12, 1984. The factors controlling relative sea-level change along our shores are varied and, at best, imperfectly understood. Yet, the relative rate of change is what controls shoreline erosion, the arrangement of sedimentary facies of the coastal zone, and the character of deformities within the coastal stratigraphic record. Therefore, these papers address sea-level changes, shoreline responses, and the controls on the three-dimensional geometry of the consequent lithosomes; in short, the architecture of the coastal depositional systems.