Micro- and Nanotexture and Genesis of Ball Clays in the Lower Cretaceous (SE Iberian Range, NE Spain)

Ball clay deposits in the SE of the Iberian Range (NE Iberian Peninsula) consist of Albian clays and siltstones with greyish and blackish colors, interbedded with subbituminous coals. The ball clays are nowadays mined for the manufacture of white color ceramics. The mineralogy of these deposits consists mainly of kaolinite, illitic phases, and quartz. The euhedral to sub-euhedral morphology of the kaolinites suggests their in-situ origin. The anhedral morphology of the illites and the presence of frayed illites suggest a detrital origin. At the micro-scale, authigenic kaolinite booklets are observed filling pores and forming mica/kaolinite intergrowths, in which the kaolinite grows between the cleavage sheets of pre-existing detrital mica. At nanometer scale, illite/smectite (IS) phases are detected forming interlayers with mica and kaolinite, and evidence of the replacement of mica by kaolinite is observed. The matrix consists of defective illite and kaolinite, and random mixed layers of kaolinite-I/S (Kln-IS), illite-I/S (Ilt-IS), and I/S-smectite (IS-S). The textures of illite and the presence of different types of mixed layers suggest that the expandable phases and kaolinite are products of mica alteration. The effectivity of the alteration was probably a consequence of the low pH that occurred in the environment due to the presence of abundant organic- and acidic- rich fluids.

A spatial connectivity approach to landscapes of conflict: Julius Caesar and the assault to Puig Ciutat (NE Iberian Peninsula)

Landscape plays a vital role in the development of military campaigns through the definition of geostrategic landmarks that structure the control of the territory, the imposition of constraints to the movement of armies, and the identification of positions that facilitate defensive tactics against aggressors. These factors are linked to the study of past spatial mobility which is typically performed using Least-Cost Path analysis (LCP). LCP identifies the optimal route that connects any two given points based on minimizing the accumulated cost based on a friction surface map, thus allowing archaeologists to identify the most efficient pathways across a territory. The main challenge of LCP analysis for archaeological regions is that optimal pathways are not well suited to define general mobility patterns within highly uncertain scenarios. Connectivity modelling based on Circuit Theory (CT) is an alternative approach to the study of mobility. CT does not generate a single path like LCP does; it captures the connectivity of an entire region identifying not only optimal paths, but also bottlenecks, dead-ends and any other spatial feature that may impact movement.We present here a framework to study landscapes of conflict using connectivity modelling; the framework combines CT, visibility analysis and statistical hypothesis testing to understand the reasons behind the assault and destruction of Puig Ciutat (NE Iberian Peninsula) during Julius Caesar's civil war. Results suggest that the site exerted decisive control over a highly connected area linking two possible logistical bases (Emporion and Massalia) to the armies fighting at Ilerda (49 BC).

Synoptic patterns favouring lightning-ignited wildfires in Catalonia

<p>Wildfires cause substantial losses to socio-economic and natural assets, especially in Mediterranean-climate regions. Despite human activity is the main cause of wildfires in Mediterranean European countries, lightning-ignited wildfires should be also considered a major disruptive agent as they can trigger large fires. Besides, recent studies on the potential climate change effects on wildfires pointed out that lightning-ignited wildfires may gain relevance in Mediterranean areas in the years to come.</p><p>In this regard, the present study analyses the meteorological conditions favouring lightning-ignited wildfires in Catalonia (NE Iberian Peninsula). Gaining insight into circulation types favouring thunderstorms that ignite wildfires can be useful in the forest protection tactical decision-making process, i.e. locating ignitions and potential holdover fires, preparing for days with multiple ignitions or routing detection flight paths.</p><p>It is worth noticing that one of the reasons why lightning-caused wildfires are difficult to manage is that they can survive for several days before flaring up. That is, even if forest fuels remain damp after the thunderstorm’ rainfall, lightning ignitions may survive smouldering underneath, emerging days later as surface vegetation becomes dry enough to support sustained combustion.</p><p>For this reason, on a first step, a reliable lightning-wildfire association is needed to properly identify the date and time of the firestarter for each wildfire. Afterwards, the circulation types on the days of ignition are analysed.</p><p>The study relies on a dataset of more than 750 lightning-ignited wildfires, gathered by the Forest Protection Agency of the autonomous government of Catalonia between 2005 and 2018. Lightning data comes from the Lightning Location System operated by the Meteorological Service of Catalonia.</p>

CULTURAL DEVELOPMENT OF THE PALLARS REGION (NE IBERIAN PENINSULA) FROM THE BRONZE AGE TO THE PRESENT

This manuscript is an abridged translation of the Catalan book entitled: "Història del Pallars. Dels origens als nostres dies", edited by C. Marugan and V. Rapalino, published by Pagès Editors (Lleida) in 2005. The manuscript contains the archaeological and historical information needed for paleoecological research in the Pyrenean Pallars region, especially for the interpretation of vegetation and landscape dynamics inferred from high-resolution palynological analyses of the annually-laminated sediments of Lake Montcortès, which contain the longest, continuous and absolutely varve-dated sequence of the Mediterranean region encompassing the last 3000 years (Late Bronze Age to present).