Paleoenvironmental analysis of the Suriname River and the coastal area, northeastern South America
The low-lying coastal plain of Suriname, which is important to the country's population and economy, is becoming increasingly vulnerable to sea level rise caused by climate change. Suriname's coastline is naturally protected by a dynamic system of mangrove forests, hydrodynamic processes and sediment deposition. It is strongly influenced by the variation in discharge mud and silt from the Amazon River through the cycle of longshore migrating mud banks.
Earth scientist Kathleen Gersie investigated the role of sediments from the Amazon River, the Suriname River and other small rivers in the geomorphological development of the Suriname coastal plain from the Paleogene to the present. To answer the research questions, she used a combination of palynological and geochemical analyses, light microscopy, satellite imagery, and historical geomorphological and topographic maps.
The Paleocene-Eocene Thermal Maximum, also known as the PETM, was recorded in Paleogene sediments. The same is true of a major shift in the composition of mangrove forests between the Paleogene and Neogene, independent of Amazonian influence. During the Pliocene-Pleistocene, the development of coastal vegetation coincided with a transition in sediment supply from local rivers originating from the Guiana Shield to the supply of material originating from the Andes.
River terraces along the Suriname River reflect different guiding processes: terraces in the upper and middle flowing river section were formed by a combination of tectonic uplift and climate-driven changes in river flow and sediment supply, while terraces along the lower river section were mainly determined by sea level fluctuations. The south-north flowing rivers of Suriname have largely kept pace with coastal progradation, while anthropogenic factors, particularly the Afobaka dam, have significantly altered the hydrodynamics and morphology of the river channel.
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