La flibuste de Saint-Domingue (1684-1727). Analyse d'un phénomène américain

Quelle est la différence entre un flibustier et un pirate ? Ce projet de recherche est basé sur cette question enfantine. En fait, les historiens contemporains, qui ont consacré de nombreuses pages à la « piraterie » et à la « flibuste » de l’âge moderne, n’ont pas réussi à répondre à cette – apparemment – simple question. Les reconstructions et les théories développées, en fait, ont assimilé ces deux phénomènes, en traitant les deux termes comme de simples synonymes. Mais, si cela peut être considéré comme vrai aujourd’hui, il n'était pas au cours des XVIIème et XVIIIème siècles. À l'époque, pirate était équivalent de « hostis humani generis », et comme tel craint et persécuté. Les flibustiers, au contraire, ont été considérés comme l’un des groupes les plus importants dans les premiers établissements des îles de la Mer des Caraïbes. En outre, le terme flibustier, dans la correspondance des gouverneurs français, se réfère à un élément considéré comme essentiel pour la réussite du processus de construction de la colonie, et également cruciale pour la consolidation des établissements américains. C’est donc la relation spéciale entre les flibustiers et le Nouveau Monde est l’objet de cette thèse. En utilisant une approche historico-culturel, on a essayé de contextualiser le phénomène de la flibuste dans le « processus d’américanisation » des premières communautés européennes en Amérique. La relation étroite entre les colons des établissements français de Saint-Domingue (aujourd’hui Haïti) et les nombreux espaces - économique, militaire, diplomatique, social, humain - des Caraïbes a fait des flibustiers un élément fortement « américanisé ». Grâce à la lecture des documents d'archives et les mémoires des années entre 1684 et 1727, on a reconstruit la dynamique de la relation entre ce groupe et le contexte américain, avec une attention particulière à la dynamique culturelle et sociale.

Strontium isotope ratios of pore waters and planktonic foraminifera from DSDP holes

A detailed record of the strontium-87 to strontium-86 ratio in seawater during the last 100 million years was determined by measuring this ratio in 137 well-preserved and well-dated fossil foraminifera samples. Sample preservation was evaluated from scanning electron microscopy studies, measured strontium-calcium ratios, and pore water strontium isotope ratios. The evolution of the strontium isotopic ratio in seawater offers a means to evaluate long-term changes in the global strontium isotope mass balance. Results show that the marine strontium isotope composition can be used for correlating and dating well-preserved authigenic marine sediments throughout much of the Cenozoic to a precision of +/- 1 million years. The strontium-87 to strontium-86 ratio in seawater increased sharply across the Cretaceous/Tertiary boundary, but this feature is not readily explained as strontium input from a bolide impact on land.

(Supplement Table S2) Results of 230Th/U-dating

We compared the suitability of two skeletal materials of the Atlantic brain coral Diploria strigosa for 230Th/U-dating: the commonly used bulk material comprising all skeletal elements and the denser theca wall material. Eight fossil corals of presumably Last Interglacial age from Bonaire, southern Caribbean Sea, were investigated, and several sub-samples were dated from each coral. For four corals, both the ages and the activity ratios of the bulk material and theca wall agree within uncertainty. Three corals show significantly older ages for their bulk material than for their theca wall material as well as substantially elevated 232Th content and (230Th/238U) ratios. The bulk material samples of another coral show younger ages and lower (230Th/238U) ratios than the corresponding theca wall samples. This coral also contains a considerable amount of 232Th. The application of the available open-system models developed to account for post-depositional diagenetic effects in corals shows that none of the models can successfully be applied to the Bonaire corals. The most likely explanation for this observation is that the assumptions of the models are not fulfilled by our data set. Comparison of the theca wall and bulk material data enables us to obtain information about the open-system processes that affected the corals. The corals showing apparently older ages for their bulk material were probably affected by contamination with a secondary (detrital) phase. The most likely source of the detrital material is carbonate sand. The higher (230Th/232Th) ratio of this material implies that detrital contamination would have a much stronger impact on the ages than a contaminant with a bulk Earth (230Th/232Th) ratio and that the threshold for the commonly applied 232Th reliability criterion would be much lower than the generally used value of 1 ng g^-1. The coral showing apparently younger ages for its bulk material was probably influenced by more than one diagenetic process. A potential scenario is a combination of detrital contamination and U addition by secondary pore infillings. Our results show that the dense theca wall material of D. strigosa is generally less affected by post-depositional open-system behaviour and better suited for 230Th/U-dating than the bulk material. This is also obvious from the fact that all ages of theca wall material reflect a Last Interglacial origin (~125 ka), whereas the bulk material samples are either substantially older or younger. However, for some corals, the 230Th/U-ages and activity ratios of the bulk material and the theca wall samples are similar. This shows that strictly reliable 230Th/U-ages can also be obtained from bulk material samples of exceptionally well-preserved corals. However, the bulk material samples more frequently show elevated activity ratios and ages than the corresponding theca wall samples. Our findings should be generally applicable to brain corals (Mussidae) that are found in tropical oceans worldwide and may enable reliable 230Th/U-dating of fossil corals with similar skeletal architecture, even if their bulk skeleton is altered by diagenesis. The 230Th/U-ages we consider reliable (120-130 ka), along with a recently published age of 118 ka, provide the first comprehensive dating of the elevated lower reef terrace at Bonaire (118-130 ka), which is in agreement in timing and duration with other Last Interglacial records.

Isotope ratios and trace element concentrations of basalts from DSDP Leg 15 sites (Appendix 1)

Formation of the Cretaceous Caribbean plateau, including the komatiites of Gorgona, has been linked to the currently active Galápagos hotspot. We use Hf-Nd isotopes and trace element data to characterise both the Caribbean plateau and the Galápagos hotspot, and to investigate the relationship between them. Four geochemical components are identified in the Galápagos mantle plume: two 'enriched' components with epsilon-Hf and epsilon-Nd similar to enriched components observed in other mantle plumes, one moderately enriched component with high Nb/Y, and a fourth component which most likely represents depleted MORB source mantle. The Caribbean plateau basalt data form a linear array in Hf-Nd isotope space, consistent with mixing between two mantle components. Combined Hf-Nd-Pb-Sr-He isotope and trace element data from this study and the literature suggest that the more enriched Caribbean end member corresponds to one or both of the enriched components identified on Galápagos. Likewise, the depleted end member of the array is geochemically indistinguishable from MORB and corresponds to the depleted component of the Galápagos system. Enriched basalts from Gorgona partially overlap with the Caribbean plateau array in epsilon-Hf vs. epsilon-Nd, whereas depleted basalts, picrites and komatiites from Gorgona have a high epsilon-Hf for a given epsilon-Nd, defining a high-epsilon-Hf depleted end member that is not observed elsewhere within the Caribbean plateau sequences. This component is similar, however, in terms of Hf-Nd-Pb-He isotopes and trace elements to the depleted plume component recognised in basalts from Iceland and along the Reykjanes Ridge. We suggest that the Caribbean plateau represents the initial outpourings of the ancestral Galápagos plume. Absence of a moderately enriched, high Nb/Y component in the older Caribbean plateau (but found today on the island of Floreana) is either due to changing source compositions of the plume over its 90 Ma history, or is an artifact of limited sampling. The high-epsilon-Hf depleted component sampled by the Gorgona komatiites and depleted basalts is unique to Gorgona and is not found in the Caribbean plateau. This may be an indication of the scale of heterogeneity of the Caribbean plateau system; alternatively Gorgona may represent a separate oceanic plateau derived from a completely different Pacific plume, such as the Sala y Gomez.

(Table 1) Magnetozone boundaries at DSDP Site 68-502

Obtaining long, continuous, and undisturbed sections of unconsolidated Neogene deep sea sedimentary sections has been limited by (1) practical length of piston cores to about 30 meters and (2) disturbance of sediment by rotary drilling with Glomar Challenger. The relatively high deposition rates of late Neogene sediments in the North Atlantic and in the Caribbean in particular has limited penetration, with conventional piston coring, to sediments not much older than late Pliocene in the Atlantic and not even through the late Pleistocene in the Caribbean. Rotary drilling has penetrated much older sediments in both areas, but the cores suffered extensive drilling disturbance that seriously degrades the Paleomagnetism of the material. Utilization of the hydraulic piston corer on the Challenger combines the advantage of a generally undisturbed recovery and great penetration to produce long, relatively undisturbed sections of late Neogene and Quaternary sediments suitable for paleomagnetic studies. In this chapter we present paleomagnetic data from Site 502. We tried to determine relative azimuthal orientation of successive cores (see Introduction for details). Because the low latitude of the site meant a small (inclination of about 22°) vertical component of magnetization, reversals of magnetization could easily be detected only in changes in the horizontal component, as 180° shifts in the declination direction of magnetization. Based on information from the core orienting device, a fiducial line was drawn the length of each core prior to cutting it into the standard 1.5 meter sections.