Yes / Objectives: This study presents isotopic information for incremental dentine collagen and bone bulk collagen from individuals from the Canary Islands (Tenerife and Gran Canaria) to explore dietary differences during childhood life. Materials and Methods: Eight individuals have been studied, which comprises 122 δ15N and δ13C incremental dentine measurements and eight bulk bone collagen analyses. A baseline of potentially consumed food sources has been developed for comparative purposes. A FRUITS model of probable contributions of each food source towards the diet of each individual has been developed. All samples but one belongs to the later period of indigenous occupation of the archipelago. Results: The dentine collagen data are presented in correlated δ13C and δ15N plots per individual, showing the isotopic changes throughout time. δ15N values for each individual tend to be variable whereas δ13C data are generally more stable with a range of +9.1 to +14‰ for δ15N and –17.4 to –20.8‰ for δ13C. Conclusion: The isotopic analysis allows for the reconstruction of 8 dietary profiles, which allow us to estimate the different dietary protein sources. The FRUITS model shows different percentages of the primary food sources for each individual. Where both δ13C and δ15N are elevated, this could be indicative of a higher marine contribution to the diet. There appear to be two main dietary profiles identifiable in the dataset and these may be related to changes in status or place of residence. Short-term variations in δ13C and δ15N and opposing co-variance of isotopic values can be indicative of nutritional stress, although metabolic changes during growth are also considered. / PhD grant from Universidad de La Laguna—Fundación La Caixa (“Contratos Predoctorales para la formación de doctores ULL-2015”), MINECO (Ministerio de Economía y Competitividad) project “Guanches y europeos en Las Cañadas del Teide, Ocupación, Producción y Comunicación” (HAR2015-68323-P), “Erasmus+ Scholarship” given by the University of La Laguna, ERC Starting Grant project IsoCAN (grant 851733, European Comission) and the projects RTI2018-101923-J-I00 and RYC2019-028346 (Ministerio de Ciencia e Innovación)

The Isleños of St. Bernard Parish, Louisiana trace their ancestry to eighteenth century settlers from the Canary Islands. Currently, St. Bernard Parish is home to two separate Canarian heritage organizations: Los Isleños Heritage and Cultural Society and the Canary Islands Descendents Association. This thesis examines how the Isleños are currently renegotiating their cultural identity through the use of heritage via the structure of heritage organizations. I argue that under mounting economic, environmental, and political pressure, people of Canarian descent in St. Bernard Parish have begun to adjust Isleño cultural identity in order to make it more widely inclusive. This is a creative means by which the Isleños attempt to maneuver around the increasingly rapid pace of change and deal with threats to the survival of their culture.

The Canary Island pine, Pinus canariensis, is an endemic tree that forms one of the main forest ecosystems within the archipelago, and whose distribution has been reduced in the last five centuries by clear cutting for the extraction of timber and tar. It was in the XXth century that exploitation declined and reforestation programs were brought forward for the restoration of an ecosystem that harbours a number of endangered endemic species of plants and animals. In addition to reforestation efforts, an understanding of population genetic processes is also necessary for the successful conservation management of the Canarian pine forest, particularly in light of gathering evidence for local adaptation.<br /><br />In this thesis historical and contemporary gene flow within P. canariensis was studied with nuclear and chloroplast microsatellite markers. High immigration rates (0.68–0.75) were estimated as expected for an outcrossing windpollinated tree. Nevertheless, significant population differentiation (theta = 0.019, RST = 0.044) was detectable for sites separated by only a few kilometres. Within the context of reforestation programs the high levels of gene flow detected would appear to have a positive effect on reforested stands by facilitating the immigration of local alleles from natural stands into potentially genetically depauperate first generation gene pools of reforested stands.<br /><br />Historical population growth was revealed with chloroplast microsatellites for most populations of P. canariensis. Population expansions for the pine parasite weevil Brachyderes rugatus were also detected, broadly coinciding with the population expansions within the Canary Island pine forests. Given the estimated times of expansion, these population demographic increases would seem likely related to the process of colonisation of newly emerged islands or local patches after volcanic disturbance. Detection and dating of these expansions from chloroplast microsatellites was, to some degree, negatively affected by homoplasy (i.e. parallel and back mutations).<br /><br />Coalescent simulations of the evolution of chloroplast microsatellites were applied to study the effects of homoplasy in the statistical analysis of population structuring. Measures of genetic diversity based on number of haplotypes and genetic distances were differently affected. Genetic distances were underestimated but were proportional to the actual value. These effects help to explain the lower performance of statistical analyses for the detection and dating of population expansions. Further research on the effects of homoplasy in the analysis of population differentiation using chloroplast microsatellites is essential.

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Seamounts play an important role in facilitating the exchange of elements between the oceanic lithosphere and the overlying seawater. This water-rock interaction is caused by circulating seawater and controls the chemical exchange in submarine and sub-seafloor rocks. The exchange mechanism plays a major role in determining the final composition of these submarine rocks. This investigation is designed to evaluate the (i) degree of alteration and element mobility, (ii) to identify relations between alteration types and (iii) to characterise the chemical processes that takes place during seafloor and sub-seafloor alteration in the Central Atlantic region. The investigated submarine rocks are typically altered. They are composed mostly of calcite and clay minerals in addition to original magmatic feldspar, olivine, pyroxene, quartz, biotite, and amphibole.  Elemental analyses show that submarine rocks with high water-rock ratio have experienced near complete loss of Silica and alkali elements to seawater but are enriched in calcium and phosphorous. In addition, there is a strong enrichment of trace elements such as Sr, Ti, Rb and trivalent REEs in altered submarine samples that are likely residual in character. Oxygen and hydrogen isotopic values indicate a low temperature alteration process at less than 50℃.  Nannofossils were present in one sample and investigation suggests that the seamount south of El Hierro evolved from a young Canary activity rather than the early Cretaceous magmatic events as has been argued previously. / Djuphavsberg spelar en viktig roll för att underlätta utbytet av element mellan den oceaniska litosfären och det överliggande havsvattnet. Interaktionen mellan vattnet och bergarterna orsakas av cirkulerande havsvatten och kontrollerar det kemiska utbytet i undervattensbergarterna och som även spelar en viktig roll för att bestämma de slutliga produkterna i dessa bergarter. Undersökningen syftar till att (i) utvärdera graden av kemisk omvandling och rörlighet av elementen, (ii) identifiera samband mellan olika omvandlingstyper och (iii) att karakterisera de kemiska processer som äger rum vid kemisk omvandling av bergarter vid och under havsbottnen i Centralatlanten. De undersökta undervattensbergarterna är generellt kemiskt omvandlade och består av kalcit och lermineral utöver ursprungligt magmatiskt fältspat, olivin, pyroxen, kvarts, biotit och amfibol. Elementanalyser visar att de undervattensbergarter med en hög vatten-berg kvot har förlorat i stort sett all Si och nästan alla alkaliska element till havsvattnet medan en anrikning har skett av kalcium och fosfor. Dessutom har det i de omvandlade undervattensproverna skett en tydlig anrikning av spårämnena Sr, Ti, Rb och av trivalenta sällsynta jordartsmetaller. Syre- och väteisotopvärden indikerar en omvandlingsprocess vid låga temperaturer mindre än 50 °C. I ett prov fanns nannofossiler och en undersökning av dessa tyder på att djuphavsberget söder om El Hierro bildades under en yngre vulkanisk aktivitet än den magmatiska aktivitet som tidigare föreslagits som ägde rum under perioden Krita.

This diploma thesis focuses on the Canary Islands special arrangements in taxation in the context of the international trade since the end of the 18th century, which were related to their unique physiographical and socio-economical conditions. Long- term calling of a local society for a taxation which could lead the islands from a deep economic crises of the first half of the 19th century and spreading the idea of liberalism in international trade, culminated in declaration of Puertos Francos in 1852. Granting of Puertos Francos led to closing of customs houses and abolition of some duties connected with the foreign exchange. Thanks to the new system of taxation, by the turn of the 18th and 19th century, the Canary Islands became an important junction of the international trade and attracted interest of colonial empires, which used the islands as a starting point of the trails to their overseas territories.

No description available.

L’étude des basaltes des îles océaniques (OIB) révèle la complexité du manteau terrestre, dont la composition chimique est hautement variable. Décrypter l’implication des lithologies des roches sources et des processus à l’origine des OIB est complexe car les magmas sont transformés lors de leur ascension jusqu’à la surface. Ceci est particulièrement critique dans le cas des îles Canaries, où la lithosphère est considérée comme particulièrement épaisse (>110 km Fullea et al., 2015). Afin de mieux contraindre la composition chimique des magmas primitifs et les lithologies mantelliques plausiblement impliquées, deux éruptions historiques de l’île de Lanzarote, les éruptions de Timanfaya (1730-1736) et celles de 1824, ont été étudiées. En effet, ces deux éruptions offrent une opportunité unique d’étudier les mécanismes de génération des magmas et leurs compositions dans un contexte où le manteau est hétérogène. L’éruption de historique de Timanfaya (1730-1736) a émis des magmas qui ont évolué de basanites à basaltes alcalins, pour atteindre des compositions tholeitiques à la fin de l’éruption. La dernière éruption de l’île, en 1824, a produit des basanites extrêmement riches en volatils. L’hétérogénéité du manteau est démontrée à l’extrême à Lanzarote où une seule éruption présente une variation de compositions chimiques équivalente à la diversité de celles des OIB dans le monde. L’extrême hétérogénéité est systématique pour les compositions des roches totales et des téphras à l’échelle d’une éruption, mais est encore amplifiée à l’échelle du minéral et des inclusions magmatiques contenus dans un même échantillon de téphra.Les concentrations des éléments traces et leurs rapports dans l’olivine (e.g. Ni, Mn et Ca) sont de précieux marqueurs des lithologies mantelliques à l’origine des magmas. En effet, les rapports Ni x (FeO/MgO), corrigé du fractionnement, et Fe/Mn sont des indicateurs de lithologies avec ou sans olivines. Il est considéré qu’ils peuvent montrer, dans la plupart des cas, l’ajout d’un liquide magmatique dérivé d’une pyroxénite dans les magmas primaires. La mesure des compositions des éléments traces des olivines des éruptions de 1730-1736 et de 1824 montrent les implications variables de plusieurs lithologies mantelliques au cours du temps. Lors de la fusion d’une lithologie ne contenant pas d’olivines, comme la pyroxénite, de hautes teneurs en Ni et de faibles teneurs en Mn et Ca sont attendues. Les basanites de Lanzarote présentent les plus grandes variations géochimiques, couvrant le champ compositionnel des olivines des MORB et des OIB du monde entier, tandis que les produits plus tardifs, c’est-à-dire les basaltes alcalins et les tholéites, ont des teneurs typiques de liquides magmatiques dérivés de pyroxénites. Les teneurs en forstérite (Fo) des olivines diminuent systématiquement avec le temps durant l’éruption de 1730-1736 et la proportion de liquide primaire saturé en silice augmente dans les mélanges de magmas primitifs avec le temps. A la fin de l’éruption, les magmas tholéitiques cristallisent des olivines dont la teneur en Fo est faible, alors que les concentrations en Mn et Ca augmentent simultanément avec le rapport Ca/Al pour des rapports Fe/Mn et Ni x (FeO/MgO) relativement constants. Ces observations sont expliquées par une augmentation de la fusion par décompression à température légèrement plus faible. D’autre part, les basanites de l’éruption de 1824 possèdent les olivines ayant les teneurs en Fo les plus élevées, et des teneurs en éléments traces dépassant la variabilité des basanites de l’éruption de Timanfaya. Le fait que les basanites de Lanzarote contiennent des olivines dont les compositions en éléments traces recouvrant le champ des MORB et des liquides pyroxènitiques est expliqué par la fusion d’une source contenant des lithologies hétérogènes, induite par un flux de CO2, générant ainsi des magmas aux compositions diverses. (...) / The study of oceanic island basalts (OIB) reveals the complexity of the mantle, which composition is highly variable. Deciphering the source lithologies and processes involved in the OIB formation is challenging since the magmas are transformed on their way to the surface. This is especially critical at Canary Islands where the lithosphere is thought to be remarkably thick (>110 km Fullea et al., 2015). In order to better constrain the composition of primitive magmas and the plausible mantle lithologies involved, two historical eruptions recorded at Lanzarote island, Timanfaya 1730-1736 and 1824 eruptions have been investigated. Indeed, these two eruptions offer a unique opportunity to investigate the mechanisms of magma generation and composition in the context of mantle heterogeneity. The Timanfaya, 1730-1736 historical eruption emitted magmas that evolved from basanites through alkali basalts, finally reaching tholeiitic compositions at the end of the eruption. In 1824 the last eruption on the island produced extremely volatile-rich basanite. The heterogeneity of the mantle is demonstrated to the extreme in Lanzarote where a single eruption exhibits compositional variations similar to the span of the OIB worldwide. The extreme heterogeneity is systematic from whole rock lava and tephra at eruption scale but amplified at mineral and melt inclusion scale within a single tephra sample of the eruption.The use of trace element concentrations and ratios of olivine (e.g. Ni, Mn, and Ca) are valuable indicators of the mantle source lithology, namely, the fractionation-corrected Ni x (FeO/MgO) and Fe/Mn as probes of olivine absent or present lithologies, often taken as pyroxenite-derived component in mixtures of primary melts. The measured trace element concentrations in olivine from the 1730-1736 and 1824 eruptions reveal variable mantle lithologies involved in the magma generation with time. Higher Ni and lower Mn and Ca contents are expected when melting Ol-free source, such as pyroxenite lithologies. The basanites exhibit the largest variation covering the range of olivine in MORB and OIB worldwide whereas later produced alkali-basalts and tholeites have values typically expected from pyroxenite derived melts. The Fo content decreases systematically with time during the 1730-36 eruption and the proportion of silica-saturated primary melt increased in the parental magma mixture with time. At the end of the eruption, tholeiite magmas crystallized olivine with lower Fo content, whereas those concentrations of Mn and Ca increased together with Ca/Al at relatively uniform Ni x (FeO/MgO) and Fe/Mn, all of which is readily explained by increased decompression melting at slightly lower temperature. The basanite from the eruption that took place in 1824 has olivine with the highest Fo content and trace element variability expanding the range of the Timanfaya basanite. The fact that Lanzarote basanites contain olivine with trace element systematic spanning that of MORB and pyroxenite melt is explained by CO2-flux melting of a lithologically heterogeneous source, generating the diverse compositions. In addition, early reactive porous flow through the depleted oceanic lithosphere and equilibration with harzburgite restite caused Ni depletion of the earliest percolating pyroxenite melt from which olivine crystallized and probably leaving dunite channels. After the channel formation mantle nodules could be brought to the surface. The fact that olivine compositions and basanite magma were reproduced approximately a century later may reflect episodic carbonatic fluxing in the slowly uprising Canarian mantle plume. (...)

During 2020 and 2021, a migration crisis has been developing on the Canary Islands in Spain. Large numbers of African migrants have made the dangerous journey from West Africa to the Canary Islands, risking their lives on the Atlantic Sea. Humanitarian aid organizations, like the Spanish Red Cross, are working intensively to handle the humanitarian needs of the migrants on land and on sea. The purpose of this thesis is to analyze why the migration crisis on the Canary Islands occurs. The migrants originate from different African countries with different reasons why they choose to migrate. In some countries, there are ongoing wars and conflicts, like in Mali. In other countries, people migrate because of poverty, climate change and displacement to seek a better life. This thesis will answer why Senegalese people choose to migrate on this dangerous route on the Atlantic Sea. The study is based on interviews with three Senegalese migrants and two representatives of humanitarian aid organizations. The analysis has been made from different migration theories. It shows that an important reason why the Senegalese migrants choose to migrate is that it is no longer possible to make a living by fishing and provide for their families. This works as an important push factor to migrate. Another push factor is the lack of trust in the Senegalese government. An important pull factor are the success stories from migrants who have made the journey through the Canary Islands. According to the aspiration and capabilities theory, the aspirations to migrate increase when a country goes from being very poor to richer. This is because the knowledge about the surrounding world and the opportunities increase. The study shows that migrants are well aware of the risks when crossing the Atlantic Sea, but they choose the route because there are almost no legal ways for them to migrate.

Since the onset of the global financial crisis, urban dwellers face an increasing number of obstacles in establishing themselves on the housing market. Against this backdrop, this paper addresses the variegated dynamics of real estate dispossession in the tourist conurbation Los Cristianos/Las Américas on an intra-urban scale. First, I will present the spatio-temporal patterns of dispossession for the period 2001–2015 using the ATLANTE database (CGPJ). Specifically, I analyze mortgage foreclosures and tenant evictions, both for residential and commercial spaces. Second, I delve deeper into local experiences of dispossession of the resident population and their housing and income conditions by means of questionnaires that I conducted in 2018. The data shows that mortgage foreclosures and dispossessions of residential spaces predominate the initial years after the crisis, albeit with varied spatial incidence. However, the increase in tenant evictions from 2014 onwards points to a reconfiguration of displacement dynamics. Indeed, as stated by the interviewees, staggeringly high rent burdens have become the main driver for displacement from both living and working spaces in recent years. Given the ongoing global pandemic, further and more nuanced research is necessary to grasp how these prevailing housing insecurities are shaped during and beyond the coronavirus crisis.