Javier Fernández-Lozano

This study explores the information gathered from the landscape transformation that occurred during the intense period of Roman hydraulic gold mining activity in northwest Spain. The Sierra del Teleno and its surroundings are characterised by the presence of Quaternary glacial and periglacial deposits and, locally, Neogene alluvial sediments, which were intensely mined by the Romans. However, the mining debris often obscures natural deposits, making their identification and description a challenging task. The aim of this study is to determine the existence of specific geomorphological features that can improve the identification of anthropic elements related to mining activity. River captures and widened drainage systems are among the most outstanding structures remaining, due to the extent and complexity of the work involved. However, other mining elements, such as anthropic modification of alluvial fans, moraine deposits and rock ridges are also evident in the landscape. In many cases, these remains are linked to the hydrologic infrastructure found in the area, which mainly comprises an extensive system of natural and man-made channels and distribution water-tanks. Difficulties arise in areas where no such structures are found. Thus, the use of geomorphic elements and patterns can help to distinguish natural and anthropic landforms. Using this approach, therefore, we have performed the first systematic and detailed analysis of the morphological imprint of Roman hydraulic gold mining activity on the landscape. These data will help piece together the puzzle of how the landscape was transformed by Roman mining activity, and can contribute to discussions surrounding the new epoch: The Anthropocene.

The study and analysis of the transformation of the territory in antiquity, as a result of livestock activity, is a stimulating challenge to unravel the historical evolution of ancient societies. Within this framework, the typological analysis of sheepfolds for livestock has in recent years significantly received attention in several areas of the Iberian Peninsula. However, the southwest of the León province, which is rich in this type of construction elements, has not yet been studied in detail, so the determination of their origin remains controversial. This work presents a comparative study with other similar elements located in the Pas valley and the Liébana region (Cantabria), analyzing from a geographical, geological and climatic point of view the study of these enclosures, which served to facilitate the regrouping and protection of the livestock. These spaces, located in mountainous areas and protected by voluminous dry-stone walls, may represent the remains of a short-term vertical stockbreeding network for livestock, locally called “corrales”, from ancient times.

This contribution explores the information provided by the landscape transformation occurred during the intense period of Roman gold mining activity in northwest Spain. The Teleno Mountains and its surroundings are char-acterised by the presence of Quaternary glacial deposits and Paleogene-Neogene alluvial sediments intensely exploited by the Romans. However, mining debris often obscures the identification and description of natural deposits , representing its study a challenging task. The aim of this study is to determine the existence of specific geomorphological features that can improve the identification of anthropic elements related to the mining activity. Among the most outstanding remains, fluvial captures and widening drainage systems are the most astonishing structures, due to the extent and complexity of the works. However, other mining elements such as anthropic allu-vial fans and rock ridges stands out in the landscape. In many cases, this mining remains are linked to the hydraulic infrastructure displayed in the area, which mainly comprises an extensive system of canals and water reservoirs. Difficulties arise in those areas where no such structures are found. Thus, the use of geomorphic elements and patterns can help to distinguish among natural or anthropic deposits. The proposed approach represents the first systematic study carried out to provide a detailed analysis of the morphological expression of Roman gold mining activity on the landscape, and it can contribute to assemble the puzzle of Roman occupation in northwest Spain.

This contribution discusses the potential of UAV-assisted (unmanned aerial vehicles) photogrammetry for the study and preservation of mining heritage sites using the example of Roman gold mining infrastructure in northwestern Spain. The study area represents the largest gold area in Roman times and comprises 7 mining elements of interest that characterize the most representative examples of such ancient works. UAV technology provides a non-invasive procedure valuable for the acquisition of digital information in remote, difficult to access areas or under the risk of destruction. The proposed approach is a cost-effective, robust and rapid method for image processing in remote areas were no traditional surveying technologies are available. It is based on a combination of data provided by aerial orthoimage and LiDAR (Light Detection and Ranging) to improve the accuracy of UAV derived data. The results provide high-resolution orthomosaic, DEMs and 3D textured models that aim for the documentation of ancient mining scenarios, providing high-resolution digital information that improves the identification, description and interpretation of mining elements such as the hydraulic infrastructure, the presence of open-cast mines which exemplifies the different exploitation methods, and settlements. However, beyond the scientific and technical information provided by the data, the 3D documentation of ancient mining scenarios is a powerful tool for an effective and wider public diffusion ensuring the visualization, preservation and awareness over the importance and conservation of world mining heritage sites.

The Sierra del Teleno is a NW-SE trending mountain system located in the
southern sector of the Galaico-Leoneses Mountains. It is characterized by the
presence of remnants of glacial landforms, active during most of the Upper
Pleistocene, and represented by several cirques and related deposits. Along the
northern slope the glacial features are well developed, showing multiple cirques
and moraine arcs. However, geomorphological remains are not well preserved in
the southern flank where a few evidences of glacial and fluvioglacial activity,
represented by remains of moraine deposits and terraces, are partially transformed.
Moraines have been intensively affected by goldmining works carried out during
the Roman times, comprising the presence of a complex hydraulic system with
canals and water reservoirs used for the transport and storage of water needed
for the roman works. Thus, hiding the effect of natural processes on the landscape
and the identification and preservation of glacial landforms. We present the
preliminary results of the mapping of glacial remains based on the integration of
natural and human-induced transformations occurred in historical period.

La técnica LiDAR basada en el escaneado de la superficie terrestre permite la obtención de modelos digitales del terreno de alta resolución. Esta tecnología ha sido ampliamente utilizada en los últimos años en trabajos de arqueología para la caracterización de elementos del patrimonio como estructuras y edificios antiguos, siendo especialmente eficaz en zonas con intensa vegetación o de difícil acceso, donde las labores de prospección se complican. Entre sus principales ventajas en comparación con otros métodos tradicionales de exploración arqueológica, destaca la posibilidad de controlar parámetros como la altura y el ángulo de incidencia de la luz para mejorar la visualización de los datos, facilitando la interpretación de la información obtenida. En este trabajo presentamos una cartografía que integra LiDAR y fotografía aérea para la identificación del entramado minero romano en el noroeste peninsular. La presencia de importantes yacimientos de oro propició una intensiva labor extractiva durante el primer siglo b.C. A pesar de que gran parte de las labores se concentraron en la zona leonesa de las Médulas y las Omañas, cabe destacar la presencia de importantes yacimientos a lo largo de los valles del río Duerna y Eria. En este estudio presentamos los resultados obtenidos que completan los trabajos realizados previamente a lo largo del río Eria (Valdería), aportando nueva información sobre la distribución de obras hidráulicas y la geometría de las principales explotaciones antiguas romanas. PALABRAS CLAVE: LiDAR, minería de oro, sistema hidráulico, España, Imperio Romano. ABSTRACT: Based on the scanning of the Earth's surface, LiDAR technology allows the compilation of high resolution digital terrain models. This technique has been widely used in recent years in archeological works to characterize heritage features and ancient human-made structures and buildings. It is particularly effective in areas with dense vegetation or difficult to access, where traditional surveying is intricated. Unlike other traditional methods in archeology, LiDAR enables to control parameters such as height and angle of light incidence, enhancing data visualization and aiming for the interpretation of obtained information. In this work we presented a detailed mapping that integrates LiDAR and aerial photography for the identification of Roman mining works in northwest Spain. The presence of significant gold deposits led to an intensive extractive labor during the first century bC. Although much of the present-day work was focused on the León area of Omañas and Las Médulas, it is important to remark the presence also of large deposits along the nearby valleys of the Duerna and Eria rivers. In this study we present the results of a detailed digital mapping that completes the previous work along the Eria (Valdería) river, providing new insights into the distribution of a complex hydraulic system and the geometry of the main ancient Roman gold mines.

The Eria Gold Mining District represents one of the most extensive Roman mining remains in the northwest
of Spain. Gold mineralization in this area is associated with quartz veins and dykes in Paleozoic rocks (primary) and Miocene and Quaternary sediments (secondary). Hitherto, ancient prospection works in Miocene materials were focused on the location of alluvial fan deposits according to the Roman literary descriptions. However, the finding of mining areas and remains of hydraulic structures located in reddish-orange hillside deposits suggests that there may have had other prospective indicators. We present a mineralogical study of optical microscopy and X-Ray diffraction for the provenance analysis of iron oxides studied in pebbles (within these sediments) and ironstone deposits located next to the main mining areas. The formation of secondary goethite, probably related to the recent chemical weathering of chlorites (formed during Variscan metamorphism), could be the responsible for the intense reddish coating. This could have served to Roman miners as gold signs, beyond other indications such as texture and roundness of rockpebbles in sediments.

La tecnología LiDAR permite la obtención de Modelos Digitales del Terreno de alta resolución. Su aplicación durante la última década en trabajos de arqueología para la caracterización de ele-mentos del patrimonio como estructuras y edificios antiguos ha demostrado ser de gran eficacia en zonas con intensa vegetación o de difícil acceso, donde las labores de prospección se complican. Entre sus principales ventajas, en comparación con otros métodos tradicionales de exploración arqueológica basados en técnicas fotogramétricas, destaca la rápida obtención de datos en forma de nube de puntos y el fácil manejo de los mismos para su posterior tratamiento y transformación en un modelo digital mediante Sistemas de Información Geográfica; el uso de SIG permite con-trolar los parámetros de visualización para mejorar el análisis de los mismos, facilitando la caracterización e interpretación de la información obtenida. En este trabajo presentamos una carto-grafía basada en la aplicación de LiDAR aerotransportado para la identificación del entramado minero romano en una parte del noroeste Peninsular. Los resultados obtenidos aportan nuevos datos sobre la distribución de obras hidráulicas y yacimientos desconocidos y/o escasamente descritos hasta el momento, arrojando luz sobre la capacidad del LiDAR para la identificación de antiguas labores mineras del oro, especialmente en zonas densamente cubiertas de vegetación. Abstract LiDAR technology allows the production of high resolution Digital Terrain Models. During the last decade, the application for identification of heritage elements and other ancient remains in archaeology has extensively contributed to study areas difficult to access or covered by a dense vegetation, where archeological surveys become complicated. Besides that, the main advantages over other traditional methodologies used in archaeological exploration such as photo-grammetry, highlights the rapid collection of data as a point cloud, simplifying the processing and conversion into a digital model by Geographic Information Systems software platforms; the control of displaying parameters is facilitated and data analysis is improved, simplifying the characterization and interpretation of the obtained information. In this work we present a mapping based on the application of airborne LiDAR to identify the Roman mining works carried out in northwest Spain. So far, our results shed light into the distribution and complexity of the mining hydraulic system and location of unknown gold deposits, highlighting the potential of LiDAR for the identification of ancient mining heritage in highly vegetated areas.

LiDAR technology, based on Earth's surface scanning, allows the compilation of high resolution digital terrain models. Recently used in archaeological works for the discovery and description of heritage features such as ancient human-made structures and building ruins, it is particularly effective in areas with dense vegetation or difficult access, where surveying becomes complicated. Among its main advantages over other traditional methods of archaeological research, it highlights the possibility of controlling display parameters, which in turn facilitates data analysis and interpretation. In this study we present an integrated LiDAR and aerial photography data analysis in order to obtain a detailed map of ancient mining works within a small sector of the Roman mining district in northwestern Spain. The presence of gold deposits led to intensive extractive work during the first century b.p.t. Although many of the mining activities were focused on the northwestern area of Las M edulas and Oma~ nas, large deposits were also found along the Duerna and Eria river valleys. Our results complement previous work carried out in the Eria area (Valdería), providing new insights into the hydraulic engineering techniques and the geometry of the main Roman exploitations. This work highlights the scope of the ancient mining works and their impact on the landscape, which are much greater and more important than previously thought.

This paper reports the use of integrated geomatic applications based on LiDAR data and UAV assisted photogram-metry for the identification, description and interpretation of ancient Roman gold mining sites in Northwest Spain. The study compares Digital Elevation Models (DEMs) with different acquisition methods, resolution and accuracy for analysis of archaeological remains. DEMs have been analysed using different visualization tools, such as principal component analysis, local relief factor, multiple hillshading, sky-view-factor and openness in order to improve visualization of the models, aiming at the identification of archaeological features. Our study suggests that principal component analysis, openness and multiple hillshading were the most effective tools for identification of archaeological remains. The results indicate that 5 m LiDAR provides insufficient resolution to perform detailed analysis and accurate description of the hydraulic systems, but the use of visualization tools improved the localization and description of remains. The 1 m resolution LiDAR data highly improve the resolution and capabilities for recognition and interpretation of canals, water reservoirs and mining zones. In addition , the use of UAV technology for smaller detailed surveys has shown a powerful capacity to reduce costs and time-consuming processing calculations, gaining in data resolution. The implementation of .LAZ files allows classification and analysis of point clouds yielding similar results to LiDAR technology in vegetated areas. However, unlike airborne lasers, its application is mainly restricted to small survey areas. Our study has focused on two areas characterized by a diversity of roman gold mining elements preserved in the landscape, such as hydraulic systems (canals and water reservoirs, drained canals and other anthropic elements) and mining areas along the Eria River Valley Gold District. The work has been implemented with the creation of 3D virtual reconstructions of the selected features, which can help to visualize different elements of the archaeological record to the general public, providing a useful tool for preservation and display of cultural heritage.

RESUMEN La minería aurífera romana en el noroeste peninsular se concentra en cuatro gran-des distritos mineros: Las Médulas, Omañas, Duerna y Eria. La cuenca del Eria representa una de las mayores explotaciones auríferas —en extensión— de todo el Imperio Romano, sin embargo, es una de las que menos atención ha recibido hasta la fecha. Los trabajos arqueológicos realizados en la zona se basaban en el uso de fotografía aérea y en la prospección de campo para la elaboración de car-tografías de los sistemas hidráulicos y el análisis de los principales yacimientos. La incorporación de nuevas tecnologías, como el LiDAR aerotransportado y los vehículos aéreos no tripulados (drones o VANT), permite el estudio detallado y la adquisición de datos de elementos del paisaje arqueominero en zonas de difícil Arqueología en el valle del Duero: Del Paleolítico a la Edad Media. 5 ISBN: 978-84-946124-0-4, pp: 520-536

El uso de fotogrametría para la reconstrucción 3D, de forma rápida y efi caz, de elementos del patrimonio cultural se ha convertido en una herramienta de uso cotidiano en el mundo de la arqueología. La mejora en las técnicas de adquisición de datos y el uso de herramientas informáticas de última generación para el procesado de los mismos, permite la obtención de imágenes 3D de alta resolución. En este trabajo presentamos la documentación de dos zonas de interés arqueológico y arquitectónico muy dispares, mediante el uso de tecnología VANT, para la obtención de información tridimensional de la necrópolis neolítica de La Cabaña y el castillo de Úrbel, ambos situados en la provincia de Burgos y enmarcados dentro del Proyecto Geoparque de las Loras. En este trabajo analizamos los benefi cios y difi cultades que presenta el estudio de elementos del patrimonio, caracterizados por diferentes grados de conservación, geometría y dimensiones. La obtención rápida y precisa de modelos 3D mediante fotogrametría con drones de bajo coste facilita, además, la difusión al público general y promueve la
protección del patrimonio, constituyendo una herramienta efi caz para la toma de datos con interés arqueológico.

Northwest Spain possesses the largest Roman gold mining complex in Europe. The extent and scale of the mining works as well as the astonishing hydraulic infrastructure developed to supply water to the mining sectors caused a strong impact on the landscape. Within this scenario, the Teleno Mountains represents a natural laboratory to figure out the impact of the Roman mining anthropic activity both underground and superficial. However, the dense vegetation cover and the impact of more recent human activity in the area hinders most of the mining remains. To explore, re-evaluate and describe in detail the Roman elements, a detailed geomorphological survey is required. The location of geomorphic features on the landscape is particularly helpful in areas where neither archaeological, epigraphic nor literary sources are available. Thus, the use of geomatic methods such as airborne Light Detection and Ranging (LiDAR) and UAV-assisted photogrammetry provide high-resolution digital elevation models used for the identification, description and preservation of mining heritage remains. The image enhancement treatment of derived products is a rapid and cost-effective method for accurate mapping of the infrastructure remains with different degrees of preservation. The evaluation of the results suggests that large-scale and profound changes took place in the landscape, were linked to Roman mining, and provides a broad overview of the important human environmental impact in the light of the possible New Epoch, the Anthropocene.