Geomorphological Analysis Applied to the Evolution of the Quaternary Landscape of the Tormes River (Salamanca, Spain)

Abstract

This paper presents a geomorphological analysis of the Tormes River during the Quaternary. The Tormes River formed in the center-west of the Iberian Peninsula in the province of Salamanca. It runs along a Cenozoic basin with basement materials and through Varisco, and consists of mainly granitic and metamorphic materials, leaving a wide stream of river terraces, both erosional and depositional, that confirm its evolution throughout the Quaternary. Geomorphological analyses using Geographic Information Systems tools, Digital terrain model high resolution (MDT05, LIDAR), Orthophotos (scale 1:5000), and geological maps (1:50,000 Series Magna) have allowed different morphologies and depositional terraces to be distinguished, namely, 19 levels of erosional terraces and 3 levels of erosion surfaces. Based on these correlations, the levels of terraces in the Tormes River between T1 (+140 m) and T7 (+75–80 m) are located in the Pleistocene, those between T8 (+58–64 m) and T14 (+18–23 m) in the Middle Pleistocene, those between T15 (+12–13 m) and T17 (+6–7 m) in the Upper Pleistocene, and those between T18 (+3 m) and T19 (+1.5 m) in the Holocene. The erosion surfaces are divided into six levels: S6 (+145 m), S5 (+150 m), S4 (+160 m), S3 (+170 m), S2 (+180 m) and S1 (+190 m) located in the Lower Pleistocene, This work performs a geomorphological mapping procedure applied to the evolutionary analysis of the landscape, so that it determines different geomorphological units allowing the relief and morphology of the terrain in past times, establishing a dynamic analysis of the landscapes.

Geomorphological Map and Quaternary Landscape Evolution of the Monfragüe Park (Cáceres, Spain)

“…Another aspect to consider is the analysis of the Quaternary deposits from the point of view of their age (chronology) based on the sequences of the fluvial terraces of the two rivers that cross the area (Tagus and Tiétar), obtaining a relative chronology comparable to those deduced in other areas of the Tagus and Duero Basins, where paleomagnetic, radiogenic (ESR, TL, OSL), isotopic (cosmogenic nuclides), paleontological dates, etc. [12,[17][18][19][20]35], geomorphology (heights of the terraces, soils, cementations, etc.) and correlations based on the heights of significant scarps [36] data are available.…”

“…and correlations (paleontological with macro-microfauna and pollen, archaeological, paleomagnetic, and stable isotopes to correlate paleoenvironments). The most relevant articles, among others, that have been taken into account refer to sequences for the Iberian Peninsula [11], Tagus basin sequences [12][13][14] and Duero basin sequences [15][16][17][18] and sequences for Tagus-Duero basins [19,20] The objective of this work is to carry out a detailed geomorphological cartography, which allows the interpretation of the different landscapes of the Quaternary and to determine its palaeogeographic evolution. Based on the spatial position of the quaternary fluvial deposits (terraces) and their correlation with sequences from the same Tagus Basin or with basins whose behavior is similar (Duero Basin), create a relative chronology that helps us to determine the ages of the paleogeographic changes of the river course of the Tagus river and as a consequence of the moments of activity of the Alentejo-Plasencia Fault.…”

Hydrogeomorphology as a Tool in the Evolutionary Analysis of the Dynamic Landscape—Application to Larrodrigo, Salamanca, Spain

“…Spatio-temporal analysis of the landscape makes it possible to understand some of the physical phenomena that interact with and modify the surface of a given region. These analyses provide information for the formulation of evaluation and management plans for landscapes subject to degradation or anthropic intervention, including, for example, abandoned mines [1], fluvial spaces [2], contaminated sites, or landscapes modified by soil and vegetation involvement [3].…”

“…Geomorphic landscape studies have employed geographic information systems (GIS), which have been developed extensively in recent decades. The tools for measuring the topography of riverbeds and hillslopes have advanced exponentially, going from topographic maps, with high fieldwork requirements and low precision, to terrain models and digital maps, which cover large portions of the territory with high resolution [3,4,[10][11][12].…”

Análisis geoambiental aplicado a la evaluación estratégica de la ciudad de Salamanca y alrededores. Cartografías temáticas mediante SIG

“…Por último, con cotas relativas menores a 8 metros, y desarrolladas durante el Holoceno, aparecen sistemas de terrazas con escalones muy tendidos, pertenecientes a lo que sería la llanura de inundación, y que en algunos puntos abarcan importantes extensiones, como en Valverdón, Florida de Liébana, Villamayor, Salamanca y Pelabravo. La prolongación de los sistemas de terrazas hacia los cursos secundarios es poco frecuente (Goy et al, 2019).…”