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

Abstract

From the geomorphological cartography, the geometric and spatial distribution of the quaternary forms and deposits are analyzed, with special relevance to the fluvial terraces that allow obtaining the chronology of the successive landscape changes of the course of the Tagus River attributed to the activity of the Fault of Alentejo-Plasencia (APF). The “Appalachian” relief of Monfragüe National Park, constituting a series of quartzitic combs with direction NW, between which they find slopes, hills and valleys following the same direction, for the dismantlement of the Cenozoic cover that was covering the substratum (still present in the central sector) and encasement of the Rivers Tagus and Tiétar. The remains of fluvial terraces inside and outside the Park stand out at different heights and so they originate from different times and show different landscapes along the routes of the Tagus river and its movement over time. In the north end (basin of the Campo Arañuelo), there are remains of ten fluvial terraces of relative importance attributed to the River Tagus (with heights relative to the thalweg between 120 and 20 m). In the south edge, there are eight levels attributed to a former fluvial drainage network, which assimilates to the River Tagus, with the more recent level reaching over 280 m on the current river. Neotectonics readjustments that rejuvenated the relief produced the elevation of the socle and cover, at the time of diversions in the path of the fluvial network, up to the structure and encasement (for supertax and/or antecedence). During the Quaternary, the activity of the Alentejo-Plasencia Fault (APF) has given rise to palaeogeographic changes in the fluvial valley of the Tagus River. During the ancient Lower Pleistocene, its course passed south of the current one (Talaván-Torrejón el Rubio basin); at the end of the Lower Pleistocene, it came out crossing the syncline through the Boquerón porthole, and the meander that bordered the town of Almaraz was abandoned; at the beginning of the Middle Pleistocene, it changes its direction, from NE–SW to SE–NW, leaving the porthole and joining the Tiétar river within the Park; later it moves somewhat to the south. These changes in the route and the anomalous fitting of the course of the Tagus River into the Paleozoic substrate, have been attributed to the APF, which, through impulses, has had a great activity from the Lower Pleistocene to the Middle Pleistocene.

Quaternary geomorphological and climatic changes associated with the diversification of Iberian freshwater fishes: The case of the genus Cobitis (Cypriniformes, Cobitidae)

“…The divergence of the two other lineages comprising the western and the eastern Alagón sub‐basin populations (V1 and V2) also occurred during the Pleistocene (Chibanian period, ~80,000 Mya). The complex geology of the Alagón sub‐basin is evident by the anomalous current trajectory of some of its rivers (Carrasco & Pedraza, 1991 ; Díez Herrero, 2003 ; Goy et al, 2020 ; Jiménez, 1994 ; Schnabel & Gutiérrez, 2014 ). For instance, the two banks of the Alagón sub‐basin, represented by the two mitochondrial lineages, are currently joined by the mouth of the Árrago River in the Alagón River, that is, the main river of the western and the eastern Alagón sub‐basin, respectively.…”

“…Several studies have reported on the genetic structure of freshwater fauna associated with connections between the Tagus Basin and adjacent basins (e.g., Alagón, Alberche and Lozoya rivers; Carmona et al, 2000 ; Casas‐Sainz & De Vicente, 2009 ; Doadrio, 1988 ; Pérez‐González, 1980 ; Sousa‐Santos et al, 2007 ). Although recent connections may be explained as a consequence of the tectonic activity in the region (Goy et al, 2020 ), there are no geological studies that support a recent connection between the western Alagón sub‐basin (Tagus Basin) and the Águeda sub‐basin (Duero Basin), despite the close proximity of some of their river headwaters (in some cases, as little as 150 m of linear distance). A connection, however, has been hypothesized to explain the co‐occurrence of individuals with the mitochondrial genome of Squalius carolitertii (distributed in the Duero Basin) and those of S .…”

“…According to our divergence time estimations, the timing of these divergences agrees with a common period of population differentiation for many Iberian freshwater fish species, which in turn coincides with the culmination of the formation of the Iberian drainage network and the Pleistocene glacial cycles (Casal‐López et al, 2017; Corral‐Lou et al, 2019, 2021; Pais et al, 2012; Perea et al, 2016). Although geological information for the study area is scarce, several tectonic and climatic events are known to have occurred during the Quaternary near the study area, which influenced the hydrogeomorphology of the aquatic network such as the fluvial capture phenomena, the presence of paleoglaciers during the last glacial cycle, and changes in the trajectory of some rivers (Benito et al, 2003; Carrasco et al, 2013, 2015; Goy et al, 2020). Therefore, we propose several hypotheses based on the biogeography of the species, which may reveal the hydrogeomorphological evolution of the study area within the Iberian Peninsula.…”

“…Although geological information for the study area is scarce, several tectonic and climatic events are known to have occurred during the Quaternary near the study area, which influenced the hydrogeomorphology of the aquatic network such as the fluvial capture phenomena, the presence of paleoglaciers during the last glacial cycle, and changes in the trajectory of some rivers (Benito et al, 2003;Carrasco et al, 2013Carrasco et al, , 2015Goy et al, 2020). Therefore, we propose several hypotheses based on the biogeography of the species, which may reveal the hydrogeomorphological evolution of the study area within the Iberian Peninsula.…”

Formas del terreno a escala detallada en planicies aluviales y lomeríos de llanura costera tropical utilizando el enfoque geopedológico (Huimanguillo, Tabasco)

“…El pie de loma, situado en la base de las lomas, es similar a geoformas receptoras de flujos de agua y materiales clasificadas como terraza inferior, lomerío bajo plano a ligeramente convexo y pie de colina (Solís-Castillo et al, 2014;Brindis-Santos et al, 2020;Goy et al, 2020) Schoeneberger et al, 2017;Vanacker et al, 2019;Goy et al, 2020). La cumbre sobresale en el lomerío por su posición topográfica elevada y extensión (18.5 %), concuerda con geoformas indicadoras de erosión e intemperización como terrazas cumbrales y cumbres (Solís-Castillo et al, 2014;Frugoni et al, 2016) Cabe hacer notar que las formas de pie de loma, hombro y pozo petrolero han sido omitidas en la cartografía geomorfológica de lomeríos, posiblemente por su escasa superficie, y generalmente se incluyen en las laderas.…”