Floodplain construction in an anastomosed river

摘要

Fluvial environments and sedimentary facies involved in the floodplain (C2a type) construction of an anastomosed river system (Upper Parana River, Brazil) were studied. Sediment volume of floodplain deposits and sedimentation rate of each environment were obtained: channel (51.56%; 8.5mm/yr), splay (33.85%; 1.27 mm/yr), pond (8.60%; 1.0 mm/yr), abandonment (3.64%; 3.87mm/yr) and natural levee (3.41%; 2.34 mm/yr), reaching a total sedimentation rate average of 5.07 mm/yr. The causes of abandonment are also discussed.