Multiple source provenance of sediments and submarine fan formation are herein investigated based on Quaternary sandy barriers of the Brazilian Southernmost Coastal Plain. LA-ICP-MS dating on 1625 detrital zircons from marine and aeolian facies sands of four successive lagoon-barrier systems are analyzed. The characterization of Archean to Pleistocene zircons into a younger Andean (22 ± 4 Ma to 1 ± 1 Ma, 48 from 1625), Mesozoic to Paleozoic, and Mesoproterozoic (479 from 1622) populations suggest that the main feeding of sediments to the coastal plain occurred through the La Plata River drainage system. The significant contribution of sediments is transported from the mouth of La Plata River northward by longshore circulation (littoral drift). Minor contributions are also recognized as. a farther source associated with the Patagonia drainage and nearby source related to the Uruguay/Rio Grande do Sul Shield and the Paraná Basin, drained by the Camaquã and Jacuí rivers. The latter one is recognized by the contribution from Neoproterozoic to Early Paleozoic, and some Paleoproterozoic and Archean zircon grains. The definition of the sources of clastic sediments allows inferences about the origination of Rio Grande Fan where both the cold Falkland and the warm Brazil currents played a major role.

本文基于巴西最南端沿海平原的第四纪砂质屏障，研究了沉积物和海底扇形成的多种来源。分析了四个连续的泻湖—屏障系统的海相和风沙相砂中的1625个碎屑锆石的LA-ICP-MS。从太古宙到更新世的锆石到较年轻的安第斯山脉（22±4 Ma至1±1 Ma，1625年为48），中生代至古生代和中元古生代（1622年为479）的特征表明，沉积物主要用于沿海平原通过拉普拉塔河排水系统发生。沉积物的重要贡献是通过长岸环流（沿海漂流）从拉普拉塔河河口向北输送。次要贡献也被确认为。与巴塔哥尼亚排水有关的更远的水源，与乌拉圭/南里奥格兰德州大盾和帕拉那盆地有关的附近水源，由卡马奎河和贾奎河排水。后一种被新元古代到早期古生代以及一些古元古代和太古代锆石的贡献所认识。碎屑沉积物来源的定义可以推断里约格兰德范的起源，在这里，冷的福克兰和温暖的巴西洋流都起着重要作用。