Title: Quaternary Geology of South America at multiple scales: a key to understanding hydroclimatic extreme events

Authors: Dr. Daniela M. Kröhling

Affiliations: Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional del Litoral (UNL), Santa Fe, Argentina. Email: dkrohling@santafe-conicet.gov.ar   

Abstract: Unique geological features and the diverse climatic zones of South America highlight its potential for Quaternary palaeoenvironmental reconstructions. From the Andes Cordillera to the Atlantic Coast and throughout tropical to high-latitude areas, some regions are critical for understanding the complex interplay between exogenic and endogenic processes driving landscape evolution. However, some palaeoclimatic inferences on a regional or sub-continental scale based on multi-proxy data were generated without considering the morphotectonic settings. Local factors could produce spatiotemporal inconsistencies between different proxy reconstructions. Particularly, sedimentary basins allow the analysis of the interactions between tectonics, dominant surface processes, and sea/base-level changes across a range of spatial and temporal scales. They have significant implications for both paleoenvironmental reconstructions and future climate change scenarios. Large fluvial basins of South America (i.e. the Amazon and Paraná) developed along the main lowland depositional (intracratonic) basins. Extensive floodplains, wetlands, swamps, lakes, and deltas, represent vulnerable and changing quaternary depositional environments on these basins. Furthermore, Late Quaternary megafans constitute extensive distributive fluvial systems (DFS) of the Central Andean foreland basin, providing high-resolution records with potential as climate proxies of the Chaco aggradational lowlands. Focusing on terrestrial and near-shore marine sedimentary archives in typical sedimentary realms of the continent, the role of geology in reconstructing past hydroclimate variability is discussed. The occurrence of droughts from aeolian domains (represented by loess, sand dunes and salt lakes) and their relationship with large fluvial systems, the development of highly avulsive processes on DFS, the complex dynamics of the Paraná Delta since the Holocene sea-level highstand, among others, will be addressed. As the frequency/severity of hydroclimatic extreme events is increasing, enhancing geomorphic processes and landscape responses such as flash floods, fluvial and coastal floods and droughts, a deeper understanding of the dynamics of geomorphic systems at multiple scales is critical to risk mitigation strategies.  

Biography: Dr. Daniela M. Kröhling is a Senior Researcher at CONICET (National Research Council of Argentina) and a Full Professor of Geomorphology at Facultad de Ingeniería y Ciencias Hídricas (UNL-Universidad Nacional del Litoral), located in Santa Fe, Argentina. Her main research focuses on reconstructing climate and environmental changes based on Quaternary Geology in key regions of South America along different tectonic settings. From 2011 to 2019, she served as the Secretary/Webmaster of the TERPRO Commission of INQUA. Currently, she is part of the coordinator team for the 3rd phase of the PAGES Floods Working Group (2024-2026).