• Energy Research

This work performs a geomorphological mapping procedure applied to the evolutionary analysis of the landscape, such that it groups different geomorphological units photointerpreted in large geomorphological domains. This allows greater utility and ease of identification and application in the different multidisciplinary studies of environmental geology and the evolution of the landscape. Geomorphological analysis allows the investigation of the reconstruction of the relief from the processes that have shaped the landscape over time. This work is a tool for the analysis of palaeolandscapes and palaeoreliefs applied to correct environmental and sustainable planning of the territory. The process starts from a morphostructural zoning in which they are grouped according to their erosive and depositional forms and the morphogenetic system to which they belong: structural, fluvial, gravitational, and polygenic. The procedure is applied to two natural parks: Batuecas and Quilamas, differentiating 18 geomorphological domains. The 2D and 3D cartographies have been implemented in virtual 3D balloons allowing a greater ease of landscape analysis in the spatial distribution of the different units over orthophotographs. The morphological and chronological evolution of the evolution of the landscape is established from the relative age of the lithological units and the geomorphological domains, as well as by their geospatial position. Georeferenced digital mapping complies with the Inspire directive for these natural spaces.

This paper aims to study the Quaternary geomorphological evolution of the Yeltes river-valley (Duero Basin, Central Spain) primarily based on the study of the Late Neogene piedmont dissected by the river and its Quaternary terrace sequence, since fluvial terraces are excellent archives to study the landscape and climate evolution during this period. Detailed geomorphological mapping implemented in GIS-based digital elevation models was used to the further applications of existing fluvial chronofunctions (relative terrace height-age transfer functions) to establish a numerical geochronology to the sequence of fluvial terraces in the zone. The obtained theoretical ages points to an onset of fluvial incision in the zone after 2.0–2.5 Myr ago, with the dissection of the “Raña surface” (a Gelasian alluvial piedmont widely developed in Central Spain). The obtained terrace ages coincide, in most cases, with warm isotopic stages (MIS) or mainly with the transit of cold to warm MIS. Additionally, this study suggests that the full connectivity of the Yeltes drainage (Ciudad Rodrigo Basin) with the Atlantic drainage was not completely effective until MIS 9 (c. 0.29 Myr). The new reported data allows for the exploration of the timing and processes involved in the capture of inland sedimentary basins (Ciudad Rodrigo, Duero basins) by the Atlantic drainage during the early Quaternary.

The “Caliphal City of Medina Azahara” was built in 936–937 CE or 940–941 CE (depending on the source) by the first Caliph of al-Andalus Abd al-Rahman III, being recently inscribed (2018) on the UNESCO World Heritage List. The abandonment and destruction of the city have been traditionally related to the civil war (“fitna”) that started between 1009 and 1010 CE. However, we cannot rule out other causes for the rapid depopulation and plundering of the city just a few decades after its foundation. The archaeoseismological study provides the first clues on the possible role played by an earthquake in the sudden abandonment and ruin of the city. Eleven different types of Earthquake Archaeological Effects (EAEs) have been identified, such as dropped key stones in arches, tilted walls, conjugated fractures in brick-made walls, conjugated fractures and folds in regular pavements and dipping broken corners in columns, among others. Besides that, 163 structural measures on EAEs were surveyed resulting in a mean ground movement direction of N140°–160° E. This geological structural analysis clearly indicates a building-oriented damage, which can be reasonably attributed to an earthquake that devastated Medina Azahara during the 11st or 12th centuries CE. If this were the case, two strong earthquakes (≥VIII MSK/EMS) occurred in 1024–1025 CE and 1169–1170 CE could be the suspected causative events of the damage and destruction of the city.