The Interplay between Tectonic Activity, Climate and Sea-Level Change in the Suriname River Valley, Tropical South America

Abstract

Suriname is part of the Guiana Shield, a cratonic area in northern South America. It is drained by several major rivers that are characterized by river terraces. The formation of terraces along the Suriname river is closely related to climatic changes during the Quaternary, due to the effects of climate on vegetation and precipitation changes. The terraces along the Suriname River valley show levels of 5, 15, and 20 m above the current mean water level. The reason behind the scarce terrace differentiation is the limited amount of long-term vertical incision. Therefore, each level along the Suriname River valley encompasses multiple climate cycles, which cannot be separated on morphological grounds. The limited incision reflects tectonic stability, which is typical for cratonic areas. Fieldwork along the river combined with topographic maps were used to determine and correlate the various terrace levels. While in the upper part of the river, climatically induced changes in vegetation cover and sediment delivery is dominant. In the lowermost reach, sea level change is especially important.