Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

436 1 2 T H I N T E R N AT I O N A L I N Q U A M E E T I N G O N PA L E O S E I S M O L O G Y , A C T I V E T E C T O N I C S A N D A R C H A E O S E I S M O L O G Y ( PATA ) , O C T O B E R 6 T H - 1 1 T H , 2 0 2 4 , L O S A N D E S , C H I L E PATA Days 2024 K E Y W O R D S DEM Analysis, La Rinconada fault, Eastern Precordillera, Neotectonics, Quaternary deformation (1) Departamento de Geología, Facultad de Ciencias Físico Matemáticas y Naturales, Universidad Nacional de San Luis. San Luis, Argentina (2) CCT-CONICET, San Luis, Argentina (3) Instituto de Estudios Andinos “Don Pablo Groeber” (IDEAN), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina (4) Instituto Argentino de Nivología Glaciología y Ciencias Ambientales, Centro Científico Tecnológico, Mendoza, Argentina *Email: andresdrichard@gmail.com Andrés Richard (1,2) Lucía Jagoe (3) Rodrigo Quiroga (4) Victoria Alvarellos (3) ASSESSMENT OF NEOTECTONIC DEFORMATION THROUGH MORPHOMETRIC ANALYSIS : A CASE STUDY IN LA RINCONADA, ARGENTINA A B S T R A C T In the Eastern Precordillera of San Juan, Argentina, Quaternary alluvial terraces in the La Rinconada area exhibit faulting and folding due to active tectonics. This study analyzes high-resolution DEMs to calculate morphometric indices, create normalized topographic profiles, and generate Relative Elevation Models (REMs) to identify and quantify this deformation. Our findings show a concentration of knickpoints in the hanging wall of the La Rinconada fault, suggesting drainage disequilibrium and elevated erosion rates. Detailed mapping reveals that older terraces (Q4- Q7) are more deformed compared to the younger terraces (Q1- Q3), indicating ongoing tectonic activity. These results provide critical insights in neotectonics and active fault systems. I N T R O D U C T I O N The Eastern Precordillera in San Juan Province, located in central-western Argentina (31º-32º S), is an area with significant tectonic activity, evidenced by active contractional structures, high concentration of instrumental seismicity, and destructive historical earthquakes. In the La Rinconada area, Quaternary alluvial terraces are affected by faulting and folding, providing an ideal setting to study the interaction between active tectonics and climatic changes in shaping the landscape. Neotectonic structures in the region usually exhibit thrusts propagating from pre- Quaternary basement into Quaternary alluvial sediments, giving rise to fold-limb scarps in the piedmont area (Costa et al. 2000; 2014). These deformed alluvial surfaces overlying thrusts