"dig" (Developing International geoarchaeology)

Keywords: carnivore, coprolite, micromorphology, Middle Palaeolithic, stable isotopes analysis.

Acknowledgements: The authors want to thank the following institutions which supported this research: The Graduate School “Human Development in Landscapes” (Kiel University) in the frame of the German Universities Excellence Initiative and the College of Social and Behavioral Sciences of California State University Northridge, USA.

Gea in front of Chronos: Geoarchaeological Research in Roman Contexts of Andalusia, Spain

Mario Gutiérrez-Rodríguez¹ Margarita Orfila Pons¹, Francisco J. Martín Peinado² Oliva Rodríguez Gutiérrez³ Enrique G. Vargas³ Carlos M. Moreno⁴ Elena H. Sánchez López¹ Marcelo C. López⁵ Paul Goldberg⁶

¹Prehistory and Archaeology Department. ²University of Granada; Edaphology and Soil Chemistry Department. University of Granada; ³Prehistory and Archaeology Department. University of Sevilla; ⁴Art History, Archaeology and Music Department. University of Córdoba;⁵Archaeological Research Center of Castulo (Linares, Jaén); ⁶Archaeology Department. Boston University
The Roman urbanization process of Southern Hispania has been historiographically built around cities, villae and the implantation of centuriations and other agrarian systems. In parallel, Earth Sciences application to archaeological analysis has highlighted that there are many processes and activities carried out in the past that, even if they had left their mark on the archaeological record, usually become invisible to traditional analysis methods, and are a key to understand the true dimension of the urbanization process. We are referring to processes in a landscape scale as deforestation, erosion, implementation of agrarian systems, etc. as well as on site behaviours, like craft activities or even daily life actions. The creation of cities and the anthropization of their surroundings for a more effective installation of the city, or the economic resources exploitation, led to such activities. Most of the topographical changes of the Roman cities during Late Antiquity are equally invisible to traditional excavation process. Some examples are the amortization of public architecture and the great domus, where rural and craft activities supersede the traditional Roman urban lifestyle.

In this sense, and as was noted by some researchers, future directions of archaeological soil micromorphology should concentrate on deciphering the full spectrum of formation processes in historical complex urban sites and their territories, expanding case studies both spatially and temporally. In this regard, the Roman archaeological record of southern Iberia, ancient Hispania, is very heterogeneous but never explored on a micromorphological scale.

With this background, a new Project was created: Gea in front of Chronos, geoarchaeological research of Roman contexts of Andalusia. The main objective of this Project is to focus on site formation processes in roman cities, and to understand how the Roman city is progressively transformed, especially in Late Antiquity. Finally, it is an attempt to resolve how contexts in a micromorphological scale are related to daily life activities of a Roman city in southern Hispania.

The study area is the Baetica province and its adjacent territories. This space was the scene of a major urban development, and a senatorial province of the Roman Empire. It has been selected a diverse set of contexts, both urban and rural, which represents a great diversity of land use in a diachronic perspective. Thus, urban contexts, rural and agricultural installations, mining centers, pottery fabrication complexes, and halieutic activities structures are being sampled. At the same time, cities with different juridical status have been investigated, as capitals, coloniae and municipia. The research team is composed both by archaeologist, micromorphologists and soil scientists. Three different universities and a research center are involved. The authors of this poster want to present the Project in a scientific forum as well as emphasise the relevance of Soil Science and archaeological soil micromorphology in classical contexts. An oral presentation proposal titled “Urban Transformation and Site Formation Processes in the Roman cities of Hispania: a micromorphological view” have been sent to the Organizing Comitee in order to present preliminary results of this research in this forum.

The Final (Asturian) Problem: reviewing the formation of the Mesolithic shell middens of northern Spain using micromorphology and other geoarchaeological approaches
Carlos Duarte, Eneko Iriarte & Pablo Arias
Instituto Internacional de Investigaciones Prehistóricas de Cantabria (IIIPC), Edificio Interfacultativo, Universidad de Cantabria, Avda. de los Castros, s/n, 39005 Santander - Cantabria – SPAIN
In the early 20^th century, the Count Vega del Sella defined the Asturian, a Mesolithic culture in the littoral platform of the Cantabrian region (northern Spain), based on the particular shell middens (concheros) found in several caves in the region, and its particular lithic industries as well. Since then it has been a traditional topic of investigation in the region. However, the knowledge about the Asturian shell middens still lacks information about the formation and post-depositional processes. This is due to the scarcity of geoarchaeological approaches carried out in these contexts.

An Asturian shell midden is a deposit cemented by calcium carbonate precipitation in the walls and ceilings of karstic cavities, with large amounts of marine shells and other archaeological materials, dated mainly to the Mesolithic. There are more than one hundred sites identified, but only a few preserve shell middens in stratigraphy. Vega del Sella interpreted these “speleothemic shell middens” as originally anthropogenic accumulations that filled the caves completely during the Mesolithic and got eroded afterwards, remaining only the parts cemented by calcium carbonate.

This interpretation implied that the same process of complete fill of caves with mollusc shells matrix anthropogenic sediment followed by massive erosion of such big deposits in all these caves took place in all the sites along the Cantabrian region. We consider that this bears problems that compromise the interpretation of its archaeological record: 1) At the present, no archaeological context provides evidence of a direct stratigraphic correlation between preserved Mesolithic shell-rich layers and the cemented ones; 2) what erosional event in the middle-late Holocene could have been responsible for emptying all the caves known in the region, leaving only the cemented parts? Ultimately, we consider that it can not be assumed that the cemented shell middens correspond to the original anthropogenic accumulation in its primary position.

However, this hypothesis can be tested using geoarchaeological techniques. In the present contribution we present the geoarchaeological approach applied in some of these contexts in Cantabrian region. Micromorphology, in particular, is considered to have great potential to answer these open questions. The thin sections from oriented block samples obtained both in cemented shell middens and anthopogenic features (e.g. combustion features) with shell matrix in stratigraphy, allowed the contextual preservation of the arrangement of the components and the post-depositional processes. The microstructure provides insights on the processes of accumulations of the anthropogenic components, preserving the chronological and spatial relationships between the various processes. Apart from the formation processes, this approach also generates useful palaeoenvironmental data concerning the speleotheme precipitation, since the morphology of these structures respond to very particular environmental conditions, that can be used in the cultural integration of the Mesolithic societies in the region.

Cova Colomera (Southeastern Pre-Pyrenees) during the late Early Neolithic: pastoral practices and bat and bird occupation
M. Mercè Bergadà¹, Tània Polonio² and F.Xavier Oms¹

1. SERP. Department of Prehistory, Ancient History and Archaeology, University of Barcelona, (Catalonia, Spain).

2. Catalan Institute of Classical Archaeology (Tarragona, Catalonia, Spain)
The Cova Colomera (Sant Esteve de la Sarga, Lleida) is located in the Pre-Pyrenees on the cliff of Montrebei in the Montsec, 670 m above sea level and 150 m above the Noguera Ribagorzana river.

The genesis of the cavity is linked to the vertical plane of a NE - SW trending fracture line in Maastrichtian limestone. It is a gallery structure 180 m long and about 10-12 m high; at the entrance of the cave dimensions range from 70 m high to 30 m wide (Oms et al., 2013).

The area under study is located in the first big chamber of the cavity, called CE, with an area of 13 m², grid squares X-32 and W-31 of those profiles were studied. These levels correspond to late cardial Early Neolithic and have radiocarbon dates between 6170 ± 30 BP and 6020 ± 50 BP (Oms et al., 2013).

Our study method was based mainly on a stratigraphic and sedimentary description of the site and an analysis of the micromorphology of the layers that were identified. We also used scanning electron microscopy (ESEM-EDX) in back-scattered electron (BSE) mode and microprobe analyses on thin sections.

The three types of facies were documented in the profiles:

- Runoff detrital facies. Consists of silty sands with limestone gravels and burnt ovicaprid excrements, silica phytoliths and plant residues. This facies is found in both profiles.

- Layer-cake facies. Developed in the upper part by an accumulation of ash composed mostly of calcite pseudomorphs of plant origin, rhombic and cubic calcite pseudomorphs and mineralized ovicaprid excrements; below that, partially charred plant residues and charcoals. This facies is located mainly in the X-32 sector.

- Biogenic facies mainly associated with bat and bird guano. It is distinguished by faecal remains, chitin fragments, gypsum nodules, yellow crytocrystalline apatite nodules and an organophosphatic crust. It is localized primarily in the area W-31 and the upper X-32.

From the results obtained through the micromorphological analysis we conclude that during the late Early Neolithic period between 6170 ± 30 and 6150 ± 40 BP there was ovicaprid pastoral activity in the area X-32, which is manifested mainly in combustion episodes. This finishes with a guano accumulation that is documented intensively in sector W-31. Later, between 6020 ± 40 and 6150 ± 50 BP, in the latter sector there is a runoff episode that is followed by guano accumulation, culminating sedimentation in this area of the cave.
Oms, F.X., López-garcía, J.M., Mangado, X., Martín, P., Mendiela, S., Morales, J.I., Pedro, M.Rodríguez, A., Rodríguez-Cintas, A., Yubero, M. 2013. Hàbitat en cova i espai pels ramats CA 6200-6000 BP: la cova Colomera (Prepirineu de Lleida) durant el Neolític antic. Saguntum, 45:25-38.

Geoarchaeology of the Bibocas quartzite rockshelter: the Late Pleistocene/Holocene scenario of Central Brazil
Daniel Vieira Sousa ¹; Carlos Ernesto Schaefer¹, João Carlos Ker¹, Maria Jacqueline Rodet²,

André Prous², Wenceslau Geraldes Teixeira³, Renê Chagas Silva⁴.

¹ Soil Department of University Federal of Viçosa. Viçosa, Minas Gerais, Brazil; ² Natural History Museum of University Federal of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; ³ EMBRAPA Soil, Rio de Janeiro, Rio de Janeiro, Brazil; ⁴ Physics Department of University Federal of Viçosa. Viçosa, Minas Gerais, Brazil

Archaeological sites developed in quartzite rock shelters, despite hindering the preservation of organic remains, have the potential to be the most ancient sites preserved, due to the low dissolution of the siliceous-rich rock and greater preservation of the shelter. The site Bibocas, located in a quartzite landscape at the western edge of the Espinhaço Range dates back to 10,470 +/- 80 years BP and extends until historical times (Rodet 2010), representing one of the oldest sites in Brazil. The anthropogenic contribution to soil formation and chemical and physical processes in rock shelters can be adequately studied by geoarchaeological methods. With this purpose, soil samples were collected from the wall of the stratigraphic section at all layers, for textural and chemical analysis: Mehlich-1 extractable P; exchangeable K⁺ Na and Ca²⁺ (EMBRAPA 2012); Total Organic Carbon (Yeomans & Bremmer 1998) and Magnetic Susceptibility by a KT-10R Plus S/C device (Terraplus-Canada). Micromorphological analyzes were carried out in undisturbed samples collected from the following layers: II (610 +/- 30); III (1.170 +/- 30); Mid IV; Lower IV; Mid V (8.580 +/- 30); V lower (9560 +/- 30), Top VI (10,470 +/- 70 years AP) and Mid VI, all according to recommendations of Bullock et al. (1985), with further suggestions of Macphail and Goldberg (2010).

The first humans to occupy the shelter came during the Pleistocene/Holocene transition. At the oldest layer, burning practices are indicated by high magnetic susceptibility, P, Ca and K amounts. The fine-fraction increase at the top VI layer section in relation to the Mid VI layer, with the greatest presence of rounded, well-selected quartz grains, suggest the income of allochtonous colluvial materials inside the shelter. The microstructure is pelicular grain and the distribution is Monic-chitonic in all stratigraphic layers. The predominant soil features are nodules, coatings (hypocoating, quasicoating) and loose, continuous or discontinuous, infillings, along pores and voids. Between 9,560 (bottom V layers) and 8580 years BP (mid V layer) the increase of lithic fragments, magnetic susceptibility, combined with increased Ca and K amounts, point to increasing shelter use and occupation. In the coarse fraction, we detected rounded rock fragments and quartz grains with widespread coating, charcoal and minute bone fragments, microflakes, nodules and concretions, associated with allochtonous materials, like metapellitic and feldspatic rocks, absent from the cave. The microstructure is also a pelicular grain with variations to bridge grain structure.

At the lower, middle, upper IV layers (8560 yars to 1170 years BP), the site was used for chipping, burning and painting activity. The fires became frequent, with increasing use for food preparation in the upper and middle IV layers, consistent with increasing amounts of Ca and P. The coarse fraction is composed of rock fragments, anahedral quartz grains, charcoal fragments of various sizes, phytoliths and typical, nucleic pseudomorphs nodules. The microstructure is pelicular grain to "bridged grain structure" with some occasional zones with granular microaggregates,

Between 1,170 and 610 years BP fire was extremely common so to originate extensive lens of soil materials containing the highest levels of OC, P and Ca. Most coarse material is rounded quartz with coatings, with common infillings, and similar pelicular grain structure.

The amounts of OC, P, magnetic susceptibility, Ca²⁺ and K⁺ were proxies of human occupation associated with fires. The Bibocas shelter site is basically an accumulation of allochtonous sediments mixed with local quartzite debris, with subsequent subtle action of pedogenic processes, forming secondary pelicular grain structure" and "Bridged grain structure". Abundant nodules of pedogenic origin, such as Feldspar degraded lithorelics and concretions, are associated with oxidation/reduction cycles, and ferruginization by burning. Geoarchaeological tools are promising for helping interpreting the anthropic evidence..