Cartografía histórica y reconstrucción paleotopográfica y geoarqueológica de la ciudad romana de caesar augusta (Zaragoza, España)

En este trabajo se ofrece una aproximación a la reconstrucción de la topografía y las características del terreno de Caesar Augusta (Zaragoza). Esta reconstrucción ha sido modelada integrando en un Sistema de Información Geográfico (SIG) el mapa topográfico de Casañal de 1880 –anterior a las principales transformaciones urbanas ocurridas en la ciudad- e información geomorfológica, geoarqueológica y arqueológica. Caesar Augusta fue fundada por los romanos junto al río Ebro en el siglo I aC sobre un asentamiento ibérico previo (Salduie). El área urbana ocupaba una terraza fluvial cuaternaria en la confluencia de los ríos Ebro y Huerva. Esta terraza se eleva unos 10 m sobre esos ríos, con altitudes que varían entre 200-208 m s.n.m. La topografía actual de la ciudad ha variado sustancialmente a lo largo del tiempo, de modo que no es apropiada para reconstruir la morfología original del terreno donde los romanos fundaron Caesar Augusta . Se ha utilizado ArcGIS 10.0 y sus módulos ArcMap y ArcScene para la gestión y análisis de los datos. Los modelos 3D generados muestran muchos elementos topográficos de detalle que en mapas anteriores pasaban desapercibidos. Estos modelos son complementados con datos de la naturaleza geológica del subsuelo provenientes de observaciones realizadas en diversas excavaciones arqueológicas. El modelo digital del terreno derivado del mapa de Casañal y las informaciones complementarias sólo son válidas para reconstrucciones generales. Sin embargo, ha mejorado nuestro conocimiento sobre muchos elementos romanos de Caesar Augusta (topografía del Decumanus y Cardo maximus , cloacas, fosos, muralla, teatro y foro). Y, es más, es ahora posible comprender mejor la geomorfología y el dinamismo fluvial de la ciudad de Zaragoza. In this paper we provide a reconstruction of the topography and characteristics of the terrain of Caesar Augusta (the Roman name of the present-day city of Zaragoza). This reconstruction has been modelled using GIS and integrating the topographic map drawn by Casañal in 1880 –previous to the main urban transforma-tions-with geomorphological, geoarchaeological and archaeological data. Caesar Augusta was founded by Romans near the Ebro River in the 1st century BC in the same place where there was a previous Iberian settlement (Salduie). The urban area occupied a quaternary fluvial terrace in the confluence of the rivers Ebro and Huerva. The terrace stands about 10 m above these rivers, with a varying height between 208-200 masl. The present-day urban topography has suffered many transformations throughout history; therefore, it is impossible to reconstruct the original morphology of the land where the Romans decided to build their town in the past. We have used ArcGIS Desktop 10.0 and its platforms ArcMap and ArcScene for managing and analysing the data. 3D models show many fine topographic features that in were overlooked previous maps. These models are complemented with information about the underground geologic nature, which is known through the observations made in several archaeological excavations. The model derived from Casañal s map and complementary data is only valid for general reconstructions, but it has enhanced our knowledge of many elements of Caesar Augusta (topography of the Decumanus and Cardo maximus, sewage system, moats, wall, theatre, forum), making it possible to better understand the geomorphology and fluvial evolution of the city of Zaragoza

Pyrogenic organic matter from palaeo-fires during the Holocene: A case study in a sequence of buried soils at the Central Ebro Basin (NE Spain)

We studied the fire record and its environmental consequences during the Holocene in the Central Ebro Basin. This region is very sensitive to environmental changes due to its semiarid conditions, lithological features and a continuous human presence during the past 6000 years. The study area is a 6 m buried sequence of polycyclic soils developed approximately 9500 years ago that is exceptionally well preserved and encompasses four sedimentary units. The content and size distribution of macroscopic charcoal fragments were determined throughout the soil sequence and the analysis of the composition of charcoal, litter and sediments via analytical pyrolysis (Py-GC/MS). The high amount of charcoal fragments recovered in most horizons highlights the fire frequencies since the beginning of the Neolithic, most of which were probably of anthropogenic origin. In some soil horizons where charcoal was not found, we detected a distribution pattern of lipid compounds that could be related to biomass burning. On the other hand, the low number of pyrolysates in the charcoal could be attributed to high-intensity fires. No clear pattern was found in the composition of pyrolysates related to the age of sediments or vegetation type. The most ancient soil (Unit 1) was the richest in charcoal content and contains a higher proportion of larger fragments (>4 mm), which is consistent with the burning of a relatively dense vegetation cover. This buried soil has been preserved in situ, probably due to the accumulation of sedimentary materials because of a high-intensity fire. In addition, the pyrogenic C in this soil has some plant markers that could indicate a low degree of transformation. In Units 2–4, both the amount of charcoals and the proportions of macrofragments >4 mm are lower than those in Unit 1, which coincides with a more open forest and the presence of shrubs and herbs. The preservation of this site is key to continuing with studies that contribute to a better assessment of the consequences of future disturbances, such as landscape transformation and climate change

Holocene alluvial sequence in the val de zaragoza (Los Monegros) in the palaeoenvironmental context of the ebro basin (Ne Spain)

Flat-bottomed valleys formed by Holocene fills are the most characteristic landforms in the center of the Ebro basin. This paper analyzes, within a regional framework, a small fluvial basin located in the north of the Alcubierre Range. Three Holocene morphosedimentary units (H1-H3) and a sub-functional level (H4) are identified. These units are representative of the regional geomorphological evolutionary process in the Ebro basin. New chronological insights on climate and landscape management are provided by a study of the Bastarás weir, a construction made for water flow management during the Little Ice Age (LIA). The integration of Val de Zaragoza radiocarbon datings into the regional framework enables the authors to identify the main formation stages, as well as the influence of climatic and human factors on its evolution. The intensification of human pressure in the territory is reflected in a progressive increase in sediment accumulation rates in the valleys, peaking during Roman times and the Little Ice Age. Los valles de fondo plano formados por rellenos holocenos constituyen los paisajes más característicos del sector central de la cuenca del Ebro. En este trabajo se analiza una pequeña cuenca fluvial localizada en el norte de la Sierra de Alcubierre, en la que se han identificado tres unidades morfosedimentarias holocenas (H1-H3) y un nivel subfuncional (H4), que son representativos de la evolución geomorfológica regional de la Cuenca del Ebro. Uno de los aspectos más relevantes del valle lo constituye el azud de Bastarás, construcción realizada durante la Pequeña Edad del Hielo para el aprovechamiento del agua, que aporta nuevos datos cronológicos sobre dicha época y acerca de la gestión del territorio. La integración de las dataciones radiocarbónicas obtenidas en la Val de Zaragoza en un marco regional ha permitido precisar las principales etapas de formación de los valles de fondo plano, así como la importancia de los factores climáticos y humanos en su evolución. La intensificación de la presión humana sobre el territorio queda reflejada en un progresivo aumento en las tasas de acumulación de sedimentos en los valles, alcanzando sus picos máximos en Época Romana y en la Pequeña Edad del Hielo

Diverse strategies for copper production in Chalcolithic Iberia

Our understanding of early copper metallurgy in the Iberian Peninsula is mostly based on analysis from well-studied regions in the Southeast and Southwest. This paper focuses on two recently recovered Chalcolithic metallurgical assemblages outside these traditional research foci: two slagged crucibles from Lugar Viejo III (Zaragoza) and two large slag cakes from Cueva del Cañaveralejo (Córdoba). Analysis of the compositions and microstructures of the artifacts using optical microscopy and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) suggests they are related to primary copper production, namely smelting in crucible-furnaces under relatively oxidizing conditions, as is standard for this period. The slag layers on crucibles from Lugar Viejo indicate the production of copper with minor amounts of arsenic, also typical for this period. Of special note is the use of organic temper in the crucibles from Lugar Viejo, a practice found at the nearby site of Moncín but rare at other sites in Iberia. However, the slags from Cueva del Cañaveralejo are atypical in their large size (approx. 125 g each), fayalitic composition, unusual efficiency as demonstrated by a low copper content, and lack of arsenic; furthermore, the high sulfur content raises the possibility of the use of sulfidic ores. Results from both sites are compared against published data from well-known sites such as Los Millares, Las Pilas, Almizaraque, and Bauma del Serrat del Pont. The new data from Lugar Viejo and Cueva del Cañaveralejo reinforce the interpretation of metallurgy in the Iberian Peninsula as a low-skilled, conservative technology but also indicate the need for more research into regional variations. (See Supplementary Data 1 for a summary in Spanish)

Caracterización geofísica de técnicas de explotación de nódulos de sílex en el yacimiento de la Leandra (La Muela, Zaragoza).

En el yacimiento de La Leandra (La Muela, Zaragoza) afloran unidades miocenas lacustres que incluyen habituales niveles de especial concentración de nódulos de sílex. Éstos han sido explotados durante varios periodos y, dadas las características climáticas y demográficas, conservan en ocasiones la topografía original desde su explotación. Con el objetivo de evaluar desde el punto de vista geofísico la estructura de una zona explotada del yacimiento, se realizó prospección geofísica por magnetometría, medidas de susceptibilidad magnética de los materiales y prospección geofísica por georradar que fueron integrados en la información obtenida de un vuelo de dron en la zona. La integración de datos obtenida permite identificar una dinámica de explotación a través de pozos verticales, continuidad lateral de las zonas de explotación generando explanadas horizontales cuando existían niveles de interés, o el abandono y posterior relleno de los huecos de explotación generados en el avance de la explotación. El caso analizado permite inferir a partir de los cambios geométricos y estructurales la progresión de las explotaciones de época previsiblemente neolítica y la identificación de una rutina de explotación a modo de minería de transferencia. In La Leandra archaeological site (La Muela, Zaragoza) Miocene lacustrine deposits outcrop and usually present levels with high concentration of silex nodules. These nodules have been exploited during several periods, and due to the weather and demographic characteristics, original topographical features related to their exploitation usually persists. With the aim of evaluating the site exploitation from a geophysical point of view magnetometry, magnetic susceptibility survey and ground penetrating radar were integrated with the obtained information from a drone flight. This analysis permits to identify an exploitation progression from vertical pits, lateral continuity of the excavation when profitable levels were found through horizontal platforms and the later filling of the excavated pits during the excavation progression. The studied case permits to infer from geometrical and structural changes the mining progression from an expected Neolithic quarry and the identification of an exploitation routine through transfer mining

Nanoparticle formation and emission during laser ablation of ceramic tiles

Pulsed laser ablation (PLA) is a widely used technology, for surface structuring and tile decoration in the ceramic industry. During PLA, nanoparticles (NP 10 nm) were formed and released during ablation of the porcelain tiles. Different release mechanisms were identified: during ablation with the near-IR laser particles were emitted through melting and nucleation, while emissions from the mid-IR laser were attributed to melting and mechanical shockwaves. Particle number and mass emissions were dependent on the tile surface characteristics (e.g., porosity, crystallinity) and chemical properties. This work is potentially relevant from the point of view of exposure mitigation strategies in industrial facilities where PLA is carried out

Diverse strategies for copper production in Chalcolithic Iberia

Our understanding of early copper metallurgy in the Iberian Peninsula is mostly based on analysis from well-studied regions in the Southeast and Southwest. This paper focuses on two recently recovered Chalcolithic metallurgical assemblages outside these traditional research foci: two slagged crucibles from Lugar Viejo III (Zaragoza) and two large slag cakes from Cueva del Cañaveralejo (Córdoba). Analysis of the compositions and microstructures of the artifacts using optical microscopy and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) suggests they are related to primary copper production, namely smelting in crucible-furnaces under relatively oxidizing conditions, as is standard for this period. The slag layers on crucibles from Lugar Viejo indicate the production of copper with minor amounts of arsenic, also typical for this period. Of special note is the use of organic temper in the crucibles from Lugar Viejo, a practice found at the nearby site of Moncín but rare at other sites in Iberia. However, the slags from Cueva del Cañaveralejo are atypical in their large size (approx. 125 g each), fayalitic composition, unusual efficiency as demonstrated by a low copper content, and lack of arsenic; furthermore, the high sulfur content raises the possibility of the use of sulfidic ores. Results from both sites are compared against published data from well-known sites such as Los Millares, Las Pilas, Almizaraque, and Bauma del Serrat del Pont. The new data from Lugar Viejo and Cueva del Cañaveralejo reinforce the interpretation of metallurgy in the Iberian Peninsula as a low-skilled, conservative technology but also indicate the need for more research into regional variations. (See Supplementary Information 1 for a summary in Spanish)