Argentina’s Diverse Landscapes: Mountains, Plateaus, and Coasts
Young Folded Mountains
The Andes Ranges: High Mountains with Glaciers
The Andes in Argentina are a magnificent mountain range, notable for their immense scale and diverse forms. They are the largest mountain range on the continent.
The Arid Andes feature a vast collection of high peaks, among the largest in the Americas and globally. The longitudinal mountain strands are isolated and partly branched clusters, separated by valleys running in both north-south and east-west directions. Mesozoic sediments were folded by a push from the west.
The Transitional Andes exhibit a noticeable decrease in altitude, featuring plateau-like reliefs dissected by deep gorges and intricate systems of high, steep walls.
The Humid Andes, in contrast to the arid regions, are characterized by an abundance of jagged peaks, ridges, ravines, and slender, steep summits. Due to their lower altitude and the moist, precipitating westerly winds, they support lush and complete vegetation.
The Fuegian Andes range accentuates the characteristics of the Humid Andes and changes its layout to a west-east orientation.
The Misiones Plateau: Dissected Mountains from Block Uplift
The Misiones Plateau, located in the province of Misiones and the northeastern corner of Corrientes (extending to the Aguapey River), is a domed plateau with a double slope that descends sharply towards the Paraná and Uruguay rivers. Its elevations also incline southwest, ranging from 800 to 150 meters above sea level.
The ancient fractured Brazilian massif was covered by Mesozoic sandstones and basalts. These later fossilized and partly metamorphosed the former. The decomposition of these materials under hot and humid weather has resulted in the superficial deposits of bright red lateritic soils that characterize Misiones.
Arid Climate Basins: Heterogeneous Sedimentation
These basins, or ‘pockets,’ have a tectonic origin and their existence has been identified in relation to various geomorphological regions. From the periphery to the center, these basins exhibit three main characteristics:
- Abrupt Faults: These correspond to the rocky walls of the surrounding mountains (e.g., the higher mountains, Pampas, and Precordillera).
- Steep Slopes: These consist of very coarse debris materials deposited at the foot of the abrupt mountain slopes.
- Basin Floor: The finest materials, such as fluvio-eolian sand and silt, accumulate on the basin floor.
Coastal Plains: Beaches, Dunes, and Estuaries
This type of coast extends from the far north, specifically Cape San Antonio, to the mouth of the Río Negro. It is characterized by its monotonous, low-lying nature, semi-lined with mobile or fixed dunes.
The beaches are sandy and, in some areas, gain significant width, extending for several miles beneath a shallow sea.
Patagonian Coastal Cliffs and Estuaries
This type of coast, situated between the Río Negro and Bahía Buen Suceso, is less monotonous. It features large cliffs separated by river valleys, often topped by sparse dunes and vegetation.
The cliffs are staggered, linking the most recently emerged terraces, which are still forming the seabed and contributing to the extended continental shelf.