(Tab. XIII.1) TOC content, carbonate content, carbonate mineralogy, percentage of total carbonate, aragonite, low magnesium calcium, and high magnesium calcium, and grain-size contents from samples from the Golfe d'Arguin and from the Western Sahara

Modern carbonate sedimentation takes place on the northern Mauritanian shelf (20°N), where typical tropical components (e.g. hermatypic reefs, calcareous green algae) are absent. Such deposits are reminiscent of extratropical sediment in the geological record. The tropical open shelf of Mauritania is influenced by large siliciclastic dust input and upwelling, highly fertilizing the ocean, as well as strongly limiting the light penetration. In this context, temperature does not appear to be the steering factor of carbonate production. This thesis describes the depositional system of the Golfe d'Arguin off Mauritania and focuses on environmental conditions that control the depositional pattern, in particular carbonate production. The description of this modern analogue provides a tool for paleoenvironmental interpretation of ancient counterparts. The Golfe d'Arguin is a broad shallow shelf comprising extensive shoals (<10 m water depth; i.e. the Banc d'Arguin) on the inner shelf where waters warm up. The sediments collected in water depths between 4 and 600 m are characterized by mixed carbonate and siliciclastic (dust) deposits. They vary from clean coarse-grained, almost pure carbonate loose sediments to siliciclastic-dominated fine-grained sediments. The carbonate content and sediment grain size show a north-south decreasing pattern through the Golfe d'Arguin and are controlled by the hydraulic regime influenced by wind-driven surface currents, swell, and tidal currents. The carbonate grain association is heterozoan. Components include abundant molluscs, foraminifers, and worm tubes, as well as barnacles and echinoderms, elements that are also abundant in extratropical sediments. The spatial distribution of the sedimentary facies of the Golfe d'Arguin does not display a depth zonation but rather a mosaic (i.e. patchy distribution). The depth and climatic signatures of the different sedimentary facies are determined by taxonomic and ecological investigations of the carbonate-secreting biota (molluscs and foraminifers). While certain planktonic foraminifers and molluscs represent upwelling elements, other components (e.g. mollusc and benthic foraminifer taxa) demonstrate the tropical origin of the sediment. The nutrient-rich (and thus also low light-penetration) conditions are reflected in the fact that symbiotic and photosynthetic carbonate-producing organisms (e.g. hermatypic corals) are absent. The Mauritanian deposits represent an environment that is rare in the modern world but might have been more common in the geological past when global temperatures were higher. Taxonomic and ecological studies allow for distinguishing carbonate sediments formed under either tropical high-nutrient or extratropical conditions, thus improving paleoclimate reconstruction.

Distribution of molluscs on the Atlantic continental shelf off Southern Spanish Sahara, West Africa

Two hundred and seventy five mollusc species from the continental shelf off Southern Spanish Sahara (depth: 32-60 m) were identified. Their distribution pattern is strongly influenced by the nature of the bottom (firm substrate, shelter, stability of sediment) rather than other factors at that depth interval. This faunal assemblage shows great affinity to the Mediterranean and Lusitanian faunas, and comprises only few (22 %) exclusively Senegalese and species living south of Senegal.

Ante la opinión nacional y extranjera. Como y quienes adminstran justicia en Bolivia. Defender el derecho es establecer la justicia. Otro caso más de injusticias, Cochabamba, 1919.

Mode of access: Internet.

Historia de la influencia extranjera en el desenvolvimiento educacional y científico de Costa Rica.

Mode of access: Internet.

Catálogo de las obras de medicina, cirugía, anatomía, fisiología y farmacia que se hallan de venta en la Librería Extranjera y Nacional de Cárlos Bailly-Bailliere.

Mode of access: Internet.

Revista de sanidad militar española y extranjera.

Mode of access: Internet.

Du Spitznberg au Sahara : étapes d'un naturaliste : au Spitzberg, en Laponie en Écosse, en Suisse, en France, en Italie en Orient, en Égypte et en Algérie /

Mode of access: Internet.

Un été dans le Sahara,

Mode of access: Internet.

Notes on Northern Africa, the Sahara and Soudan, in relation to the ethnography, languages, history, political and social condition, of the nations of those countries.

Photocopy.

U.S. policy and the conflict in the western Sahara : hearings before the Subcommittees on Africa and on International Organizations of the Committee on Foreign Affairs, House of Representatives, Ninety-sixth Congress, first session, July 23, and 24, 1979.

Includes bibliographical references.

Nouveau voyage dans l'intérieur de l'Afrique, fait en 1810, 1811, 1812, 1813 et 1814; ou Relation de Robert Adams, Américain des États-Unis, contenant les détails de son naufrage sur la côte occidentale de l'Afrique; de sa capitivité pendant trois années, chez les Arabes du Sahara ou Grand Désert; et de son séjour dans la ville de Tombuctoo.

Translation of The narrative of Robert Adams, a sailor, who was wrecked in the year 1810 on the Western Coast of Africa, Great Desert, and resided several months of that period in the City of Tombuctoo.

Observaciones sobre la intervencion que ha tenido el ex-presidente de Centro-América, general Francisco Morazán, en los negocios políticos de Guatemala, durante las convulsiones que ha sufrido este Estado, de mediados de 837 á principios de 839.

Signed on p. 17: Alejandro Marure.

A woman in the Sahara,

Mode of access: Internet.

Sahara algerien et tunisien. Journal de route de Henri Duveyrier.

Includes bibliographical references and index.