Chemical composition of basalts and minerals from basalts of the Bouvet triple junction

This study focuses on mafic volcanic rocks from the Bouvet triple junction, which fall into six geochemically distinct groups: (1) N-MORB, the most widespread type, encountered throughout the study area. (2) Subalkaline volcanics, hawaiites and mugearites strongly enriched in lithophile elements and radiogenic isotopes and composing the Bouvet volcanic rise, and compositionally similar basalts and basaltic andesites from the Spiess Ridge, generated in a deeper, fertile mantle region. (3) Relatively weakly enriched basalts, T-MORB derived by the mixing of Type 1 and 2 melts and exposed near the axes of the Mid-Atlantic, Southwest Indian, and America-Antarctic Ridges. (4) Basalts with a degree of trace lithophile element enrichment similar to the Spiess Ridge and Bouvet Island rocks, but higher in K, P, Ti, and Cr. These occur within extensional structures: the rift valley of the Southwest Indian Ridge, grabens of the East Dislocation Zone, and the linear rise between the Spiess Ridge and Bouvet volcano. Their parental melts presumably separated from plume material that spread from the main channels and underwent fluid-involving differentiation in the mantle. (5) A volcanic suite ranging from basalt to rhyolite, characterized by low concentrations of lithophile elements, particularly TiO2, and occurring on the Shona Seamount and other compressional features within the Antarctic and South American plates near the Bouvet triple junction. Unlike Types 1 to 4, which display tholeiitic differentiation trends, this suite is calc-alkaline. Its parental melts were presumably related to the plume material as well but, subsequently, they underwent a profound differentiation involving fluids and assimilated surrounding rocks in closed magma chambers in the upper mantle. Alternatively, the Shona Seamount might be a fragment of an ancient oceanic island arc. (6) Enriched basalts, distinguished from the other enriched rock types in very high P and radiogenic isotope abundances and composing a tectonic uplift near the junction of the three rifts. It thus follows that the main factors responsible for the compositional diversity of volcanic rocks in this region include (i) mantle source heterogeneity, (ii) plume activity, (iii) an intricate geodynamic setup at the triple junction giving rise to stresses in adjacent plate areas, and (iv) the geological prehistory. The slow spreading rate and ensuing inefficient mixing of the heterogeneous mantle material result in strong spatial variations in basaltic compositions.

Simulated transition to agropastoralism in the Indus valley 7500-3000 BC

The Indus Valley Civilization (IVC) was one of the first great civilizations in prehistory. This bronze age civilization flourished from the end of the fourth millennium BC. It disintegrated during the second millennium BC; despite much research effort, this decline is not well understood. Less research has been devoted to the emergence of the IVC, which shows continuous cultural precursors since at least the seventh millennium BC. To understand the decline, we believe it is necessary to investigate the rise of the IVC, i.e., the establishment of agriculture and livestock, dense populations and technological developments 7000-3000 BC. Although much archaeologically typed information is available, our capability to investigate the system is hindered by poorly resolved chronology, and by a lack of field work in the intermediate areas between the Indus valley and Mesopotamia. We thus employ a complementary numerical simulation to develop a consistent picture of technology, agropastoralism and population developments in the IVC domain. Results from this Global Land Use and technological Evolution Simulator show that there is (1) fair agreement between the simulated timing of the agricultural transition and radiocarbon dates from early agricultural sites, but the transition is simulated first in India then Pakistan; (2) an independent agropas- toralism developing on the Indian subcontinent; and (3) a positive relationship between archeological artifact richness and simulated population density which remains to be quantified.

Mobilities, Entanglements, Transformations. Outline of a Research Project on Pottery Practices in Neolithic Wetland Sites of the Swiss Plateau

A large number of later Neolithic sites (3900–3500BC) in Switzerland, Southern Germany and Eastern France offer outstandingly well preserved archaeological materials from cultural layers. Due to the wide use of dendrochronology, settlement remains and artefact assemblages can now be placed into a precise and fixed chronological framework, thus presenting a unique case within prehistoric archaeology. In earlier research, chronological and regional units were constructed on the basis of pottery. These spacial and temporal units of typical pottery sets were understood as Neolithic cultures, as culturally more or less homogenous entities connected with (ethnic) identities. Today, with a larger data corpus of excavated settlements at hand, we can begin to understand that this period of the past was in fact characterised by a multitude of cultural entanglements and transformations. This is indicated by the occurrence of local and non-local pottery styles in one and the same settlement: for example typically local Cortaillod pottery is found together with NMB-styled pottery in settlements at Lake Neuchâtel or Michelsberg pottery is regularly occurring in settlements at Lake Constance where Pfyn pottery style is the typical local one. These and many more examples show that there must have been complex entanglements of social ties expanding between Eastern France, Southern Germany and the Swiss Plateau. Given these circumstances the former notions of Neolithic culture should be critically revised. Therefore, in late 2014, the Prehistoric Archaeology Department at the Archaeological Institute of University of Berne started a four-year research project funded by Swiss National Science Foundation in late 2014: ‘Mobilities, Entanglements and Transformations in Neolithic Societies of the Swiss Plateau (3900-3500 BC)’. It’s objective is to address the topic sketched above by adopting a mixed methods research (MMR)-design combining qualitative and quantitative approaches from archaeology and archaeometry. The approach is theoretically based on Pierre Bourdieu’s reflexive sociology and his concept of habitus but includes further concepts of practice theories. By shifting the focus to the movement of people, ideas and things – to pottery production practices in contexts of mobility – a deeper understanding of the transformative capacities of encounters can be achieved. This opens the path for new insights of Neolithic societies including social, cultural and economic dynamics that were underestimated in former research.

Modelización del registro y proceso de datos espectrales, referidos a superficies líticas, en un ámbito arqueológico.

La determinación del origen de un material utilizado por el hombre en la prehistoria es de suma importancia en el ámbito de la arqueología. En los últimos años, los estudios de procedencia han utilizado técnicas que suelen ser muy precisas pero con el inconveniente de ser metodologías de carácter destructivo. El fenómeno de la minería a gran escala es una de las características que acompaña al Neolítico, de ahí que la revolución correspondiente a este periodo sea una de las etapas más importantes para la humanidad. El yacimiento arqueológico de Casa Montero es una mina de sílex neolítica ubicada en la Península Ibérica, de gran importancia por su antigüedad y su escala productiva. Este sitio arqueológico corresponde a una cantera de explotación de rocas silícicas desarrollada en el periodo neolítico en la que solamente se han encontrado los desechos de la extracción minera, lo cual incrementa la variabilidad de las muestras analizadas, de las que se desconoce su contexto económico, social y cultural. Es de gran interés arqueológico saber por qué esos grupos neolíticos explotaban de forma tan intensiva determinados tipos de material y cuál era el destino de la cadena productiva del sílex. Además, por ser una excavación de rescate, que ha tenido que procesar varias toneladas de material, en un tiempo relativamente corto, requiere de métodos expeditivos de clasificación y manejo de dicho material. Sin embargo,la implementación de cualquier método de clasificación debe evitar la alteración o modificación de la muestra,ya que,estudios previos sobre caracterización de rocas silícicas tienen el inconveniente de alterar parcialmente el objeto de estudio. Por lo que el objetivo de esta investigación fue la modelización del registro y procesamiento de datos espectrales adquiridos de rocas silícicas del yacimiento arqueológico de Casa Montero. Se implementó la metodología para el registro y procesamiento de datos espectrales de materiales líticos dentro del contexto arqueológico. Lo anterior se ha conseguido con la aplicación de modelos de análisis espectral, algoritmos de suavizado de firmas espectrales, reducción de la dimensionalidad de las características y la aplicación de métodos de clasificación, tanto de carácter vectorial como raster. Para la mayoría de los procedimientos se ha desarrollado una aplicación informática validada tanto por los propios resultados obtenidos como comparativamente con otras aplicaciones. Los ensayos de evaluación de la metodología propuesta han permitido comprobar la eficacia de los métodos. Por lo que se concluye que la metodología propuesta no solo es útil para materiales silícicos, sino que se puede generalizar en aquellos procesos donde la caracterización espectral puede ser relevante para la clasificación de materiales que no deban ser alterados, además, permite aplicarla a gran escala, dado que los costes de ejecución son mínimos si se comparan con los de métodos convencionales. Así mismo, es de destacar que los métodos propuestos, representan la variabilidad del material y permiten relacionarla con el estado del yacimiento, según su contenido respecto de las tipologías de la cadena operativa. ABSTRACT: The determination of the origin of a material used by man in prehistory is very important in the field of archaeology. In recent years the provenance studies have used techniques that tend to be very precise but with the drawback of being destructive methodologies. The phenomenon of mining on a large scale is a feature that accompanies the Neolithic period; the Neolithic revolution is one of the most important periods of humanity. The archaeological site of Casa Montero is a Neolithic flint mine located in the Iberian Peninsula of great importance for its antiquity and its scale. This archaeological site corresponds to a quarry exploitation of silicic rocks developed in the Neolithic period, in which only found debris from mining, which increases the variability of the samples analyzed, including their economic, social and cultural context is unknown. It is of great archaeological interest to know why these Neolithic groups exploited as intensive certain types of material and what the final destination of flint was in the productive chain. In addition, being an excavation of rescue that had to process several tons of material in a relatively short time requires expeditious methods of classification and handling of the material. However, the implementation of any method of classification should avoid the alteration or modification of the sample, since previous studies on characterization of silicic rocks have the disadvantage of destroying or partially modify the object of study. So the objective of this research wasthe modeling of the registration and processing of acquired spectral data of silicic rocks of the archaeological site of Casa Montero. The methodology implemented for modeling the registration and processing of existing spectral data of lithic materials within the archaeological context, was presented as an alternative to the conventional classification methods (methods destructive and expensive) or subjective methods that depend on the experience of the expert. The above has been achieved with the implementation of spectral analysis models, smoothing of spectral signatures and the dimensionality reduction algorithms. Trials of validation of the proposed methodology allowed testing the effectiveness of the methods in what refers to the spectral characterization of siliceous materials of Casa Montero. Is remarkable the algorithmic contribution of the signal filtering, improve of quality and reduction of the dimensionality, as well the proposal of using raster structures for efficient storage and analysis of spectral information. For which it is concluded that the proposed methodology is not only useful for siliceous materials, but it can be generalized in those processes where spectral characterization may be relevant to the classification of materials that must not be altered, also allows to apply it on a large scale, given that the implementation costs are minimal when compared with conventional methods.

La forma del agua. Temas e invariantes en el jardín y el paisaje. Análisis de casos (Holanda-España, 1548-1648)

El espacio geográfico, entendido como territorio que da soporte a la vida y a la civilización, ha estado siempre fuertemente supeditado a la presencia de agua. Desde la Prehistoria el hombre otorgó al agua, junto a otros elementos que aseguraban o protegían su vida, un valor superior, por encima de lo humano. Paralelamente y de manera natural, el jardín, en sus inicios en estrecha relación con la agricultura y con el paisaje, fue el ámbito idóneo para la creación de nuevas formas acuáticas artificiales. Este proceso dio lugar a un extenso repertorio de formas compositivas que parece que tuvo en el Renacimiento un punto de inflexión, en el que se observa como la mayoría de recursos y configuraciones básicas del agua estaban ya plenamente establecidas. Esta evolución y sus resultados ha sido el objeto de la primera parte de la tesis: su objetivo ha sido analizar cómo el agua configura, cualifica o puede llegar a construir el jardín y el territorio en el que se inserta, así como establecer las posibles relaciones entre estos dos ámbitos de estudio. Aunque la historia es su fundamento, el planteamiento aquí ha sido más bien conceptual; estudiando los componentes acuáticos desde un punto de vista fundamentalmente compositivo. Esta indagación previa ha sido indispensable para llegar a entender en profundidad los modos en los que el agua se muestra en el jardín y en el paisaje renacentista y manierista, momentos en que se insertan los dos casos de estudio que constituyen la segunda parte de la tesis. Sin caer en un determinismo geográfico extremo, puede admitirse que el jardín, como manifestación cultural intrínsecamente ligada al entorno, depende fuertemente del territorio en el que se asienta; hecho particularmente evidente en aquellas regiones en las que su especial geografía ha sido un claro factor condicionante de su historia. Por ello, Holanda y España han sido las dos localizaciones elegidas para profundizar en este estudio; no tanto por su estrecha relación política y cultural, sino por su profundo y sugerente contraste de medio físico y climático. La Península Ibérica, geográficamente el término del mundo conocido en Occidente hasta el final de la Edad Media, y por esta circunstancia convertida en destino, en territorio de permanencia y fusión, estará además supeditada en la mayoría de su territorio a la falta de agua, siendo a la vez heredera directa del universo y la tradición del jardín meridional originario de Oriente. En el extremo opuesto, Holanda, espacio de transición entre el mar y la tierra firme “real”, es un territorio permeado de humedad y surcado con generosidad por grandes ríos. El país, con una relación ambivalente con el agua, unas veces como amenaza y otras como fuente de nuevas oportunidades, será por el contrario especialmente favorable para el desarrollo de un modelo de jardín septentrional. Un jardín del norte, que no obstante, no surgirá de despejar los bosques, como en el arquetipo nórdico, sino que crecerá sobre planicies antes saturadas de agua o directamente anegadas. El marco temporal de los dos casos concretos ha considerado como fecha inicial 1548, momento en el que Felipe II, aún príncipe, realizó su primer viaje a los Países Bajos, y entró en contacto con el modelo holandés. La extensa producción posterior de jardines de Felipe II, siempre con el agua como protagonista, tuvo como destacado referente la adaptación al suelo y la geografía hispánicos de dicho modelo. Como fecha final se fija 1648, justo un siglo después, fecha coincidente con la firma de la Paz de Westfalia, tratado que supone la total reorganización política del territorio europeo y la pérdida de la hegemonía española en Europa. En Holanda sólo dos años después nacerá Guillermo III de Orange, estatúder de las Provincias Unidas, también futuro rey de Inglaterra, Escocia e Irlanda. Para entonces en Holanda ya se había asistido al desarrollo de un arte propio de jardín, íntimamente ligado al agua, sorprendentemente no demasiado bien conocido y que será uno de los temas de esta investigación. Finalmente, se propone una lectura conjunta de toda esta serie de intervenciones que tienen como argumento el agua, en la que se integra la información procedente de distintos campos de estudio, cada una con su metodología particular. El resultado es una tesis en la que el jardín y el territorio son tratados desde un nuevo y enriquecedor punto de vista. ABSTRACT Geographical space, understood as the territory that provides support to human life and civilization, has always been strongly subjected to the presence of water. From Prehistory man gave to water, along with other elements that ensured or protected life, a higher value than the merely human. At the same time and in a natural way, the garden, in its beginnings with a close relationship with agriculture and landscape, soon developed as the appropriate ground for the creation of new artificial aquatic forms, in a process that seems to have a turning point in the Renaissance, when most of the basic waterworks and resources were already fully established. This development and its outcomes are the subjects of the first part of the thesis: its scope has been to analyse how water configures, qualifies and might even help to construct the garden or landscape attached to it; and to establish the possible links between these two fields of study. Although history based, the point of view here is mainly conceptual, studying the water components understood as composite elements. This exploratory research has been essential to deeply understand the water patterns shown in the Renaissance and Mannerist garden and landscape, periods in which the two case studies are inserted. Without falling in extreme determinism, it can be accepted however, that garden, as a cultural expression linked to environment, is strongly dependant on territorial setting; something particularly evident in those areas where specific geography has been a clear history conditioning factor. This is the reason that leads to choose the Netherlands and Spain to deepen this study, no so much for their interesting cultural and politics relations as for the suggestive and profound contrast of their physical environment and climate. The Iberian Peninsula, geographically the limit of the known world in Occident until the end of the Medium Age, and by this circumstance understood as endpoint, more a destination than a crossroad, a territory of permanence and fusion, but also subjected to water shortage; is thus associated with the universe and tradition of the meridional garden imported from Orient. In the opposite, the Netherlands, a transitional space between the sea and the “real” firm land, is a territory permeated by water and crossed by big rivers. Always with an ambivalent relationship with water, sometimes seen as a threat and sometimes as a source of new opportunities, it was in the other hand the adequate land for the development of a special model of Northern garden. A garden that will not arise, however, from the clearing of woods as in the Nordic archetype, but that will grow on plains originally saturated of water or directly waterlogged. The timeframe of the two cases has 1548 as the initial year, moment in which Philip II, yet prince, made his first trip to the Low Lands and imbibed the Dutch garden model. The later and bountiful garden works of the king, always with the water as the main focus, adapted the imported model to the Spanish ground and geography. The final date is fixed in 1648, just a century after, in coincidence with the Westfalia Peace; a treaty that implied the total political reorganization of the European territory and the end of the Spanish hegemony in the continent. In Holland, only two years later, William III of Orange, Stadtholder of the United Provinces and also future king of England, Scotland and Ireland, was born. But by then the Netherlands had developed an own garden art, closely linked to water. This type garden, surprisingly not very well known, and its relationship with water, will be other of the addressing questions of this work. Finally, the investigation merges the different interventions that have water as an argument, integrating all the fields considered with their particular methodological approaches. The final result is a thesis in which garden and territory are treated from a new and enriching perspective.

Patterns of prehistoric human mobility in Polynesia indicated by mtDNA from the Pacific rat

Human settlement of Polynesia was a major event in world prehistory. Despite the vastness of the distances covered, research suggests that prehistoric Polynesian populations maintained spheres of continuing interaction for at least some period of time in some regions. A low level of genetic variation in ancestral Polynesian populations, genetic admixture (both prehistoric and post-European contact), and severe population crashes resulting from introduction of European diseases make it difficult to trace prehistoric human mobility in the region by using only human genetic and morphological markers. We focus instead on an animal that accompanied the ancestral Polynesians on their voyages. DNA phylogenies derived from mitochondrial control-region sequences of Pacific rats (Rattus exulans) from east Polynesia are presented. A range of specific hypotheses regarding the degree of interaction within Polynesia are tested. These include the issues of multiple contacts between central east Polynesia and the geographically distinct archipelagos of New Zealand and Hawaii. Results are inconsistent with models of Pacific settlement involving substantial isolation after colonization and confirm the value of genetic studies on commensal species for elucidating the history of human settlement.

Interisland and interarchipelago transfer of stone tools in prehistoric Polynesia.

Tracing interisland and interarchipelago movements of people and artifacts in prehistoric Polynesia has posed a challenge to archaeologists due to the lack of pottery and obsidian, two materials most readily used in studies of prehistoric trade or exchange. Here we report the application of nondestructive energy-dispersive x-ray fluorescence (EDXRF) analysis to the sourcing of Polynesian artifacts made from basalt, one of the most ubiquitous materials in Polynesian archaeological sites. We have compared excavated and surface-collected basalt adzes and adze flakes from two sites in Samoa (site AS-13-1) and the Cook Islands (site MAN-44), with source basalts from known prehistoric quarries in these archipelagoes. In both cases, we are able to demonstrate the importing of basalt adzes from Tutuila Island, a distance of 100 km to Ofu Island, and of 1600 km to Mangaia Island. These findings are of considerable significance for Polynesian prehistory, as they demonstrate the movement of objects not only between islands in the same group (where communities were culturally and linguistically related) but also between distant island groups. Further applications of EDXRF analysis should greatly aid archaeologists in their efforts to reconstruct ancient trade and exchange networks, not only in Polynesia but also in other regions where basalt was a major material for artifact production.

Nueva aplicación potencial de dos técnicas instrumentales para la caracterización de materiales de construcción prehistóricos

En este trabajo se ponen de manifiesto las ventajas de la utilización de la Termogravimetría acoplada a Espectrometría de masas (TG-EM) y de la Espectrometría Infrarroja mediante Reflectancia Total atenuada (ATR-FTIR) frente a las técnicas usadas tradicionalmente de Termogravimetría (TG) y de Espectroscopia Infrarroja por Transformada de Fourier en modo transmisión (FTIR) en el estudio de materiales de construcción prehistóricos de diversos yacimientos de la Provincia de Alicante (España).

The decomposition of starch grains in soils: implications for archaeological residue analyses

Recent research involving starch grains recovered from archaeological contexts has highlighted the need for a review of the mechanisms and consequences of starch degradation specifically relevant to archaeology. This paper presents a review of the plant physiological and soil biochemical literature pertinent to the archaeological investigation of starch grains found as residues on artefacts and in archaeological sediments. Preservative and destructive factors affecting starch survival, including enzymes, clays, metals and soil properties, as well as differential degradation of starches of varying sizes and amylose content, were considered. The synthesis and character of chloroplast-formed 'transitory' starch grains, and the differentiation of these from 'storage' starches formed in tubers and seeds were also addressed. Findings of the review include the higher susceptibility of small starch grains to biotic degradation, and that protective mechanisms are provided to starch by both soil aggregates and artefact surfaces. These findings suggest that current reasoning which equates higher numbers of starch grains on an artefact than in associated sediments with the use of the artefact for processing starchy plants needs to be reconsidered. It is argued that an increased understanding of starch decomposition processes is necessary to accurately reconstruct both archaeological activities involving starchy plants and environmental change investigated through starch analysis. (C) 2004 Elsevier Ltd. All rights reserved.