Central Cuba Research Articles

Structure, tectonics and metamorphic development of the Sancti Spiritus Dome (eastern Escambray massif, Central Cuba)

The Sancti Spiritus Dome of the eastern Escambray (Cuba) represents a metamorphic fold and thrust structure which was part of the Cretaceous subduction-accretion complex of the Greater Antillean Arc. On the basis of structural data and pressure-temperature-time evolution the metamorphic complex can be subdivided into four units interpretable as nappes: a high-grade greenschist-facies unit (Pitajones unit), a high-pressure tectonic melange (Gavilanes unit), high-pressure amphibolites (Yayabo unit) and – tectonically overlying - low-pressure metagabbros of the Greater Antillean Arc (Mabujina unit). The oldest rock fabrics are preserved in eclogite- and blueschist-facies rocks of the Gavilanes unit, indicating arc-parallel extension. Maximum metamorphic conditions are recorded in eclogites (16-20 kbar, 580-630 °C) and garnet-mica schists (16-23 kbar, 530-610 °C) of the Gavilanes unit. Field observations and fabric studies show that greenschist-facies dynamic indicators are dominated by top-to-NE tectonic transport in the lowermost nappes. The greenschist-facies shear zone between the Yayabo unit and the Mabujina unit is viewed as the main detachment zone between the subduction complex and the overlying arc complex. Active subduction ceased at about 70 Ma, followed by rapid uplift, exhumation and thrusting to the north.

Structures and petroleum prospects of the Saramaguacán basin, Cuba, from 3D inversion of gravimetric data

Se presentan nuevas particularidades estructurales de la cuenca Saramaguacán, Cuba, a partir de la inversión 3D de datos gravimétricos, constreñidos por información de pozos y geología de superficie. Esas particularidades muestran una tectónica compleja de procesos de cabalgamiento, revelando el esquema estructural más probable dentro de la cuenca, el cual indica estructuras en formas de rampa y plataforma, así como la ubicación y geometría de la cuenca y varias sub-cuencas. También se conocen las ubicaciones y comportamiento en profundidad de las principales fallas, y se sugieren posibles nuevas fallas. A las diferentes formaciones rocosas se le determinaron las variaciones de su geometría, profundidad y espesor. Esta determinación posee particular importancia para las rocas sedimentarias (rocas colectoras) y las rocas del paleomargen (rocas madres) porque constituye la base para futuras investigaciones orientadas a seleccionar los mejores sitios para ubicar las perforaciones petroleras y calcular el volumen de hidrocarburo que pueden almacenar las rocas colectoras. Ambos grupos de rocas son potenciales para la prospección petrolera. A 4 km de profundidad se localizaron las rocas madres del sistema petrolero cubano, asociadas a las rocas carbonatadas del paleomargen. Las rocas colectoras alcanzan 10 km de profundidad. El modelo 3D obtenido apoya la hipótesis de un emplazamiento tectónico de sur a norte de las ofiolitas y las rocas volcánicas cretácicas, sobre las secuencias terrigenous-carbonatadas del paleomargen de Bahamas. Las particularidades estructurales mostrada por el modelo constituyen indicadores de la tectónica compresiva que originó la cuenca Saramaguacán en el Mesozoico-Terciario. También indican que la cuenca Saramaguacán posee condiciones favorables para la preservación de petróleo.

Timing and Evolution of Cretaceous Island Arc Magmatism in Central Cuba: Implications for the History of Arc Systems in the Northwestern Caribbean

AbstractSHRIMP and conventional zircon dating place temporal constraints on the evolution of the Cretaceous Volcanic Arc system in central Cuba. The arc has a consistent stratigraphy across strike, with the oldest and deepest rocks in the south (in tectonic contact with the ∼5–10-km-wide Mabujina Amphibolite Complex [MAC]) and younger rocks in the north. The MAC is thought to represent the deepest exposed section of the Cretaceous Volcanic Arc and its oceanic basement in Cuba. We undertook a single zircon geochronological study of five gneisses and two amphibolites from the MAC and seven rocks from the Manicaragua Batholith, which intrudes both the MAC and the Cretaceous Volcanic Arc. A SHRIMP zircon age of Ma for a trondhjemitic orthogneiss (MAC) from the Jicaya River dates the oldest phase of granitoid magmatism in this area and the entire Caribbean (Antillean) region. A tonalitic gneiss collected near the previous sample yielded an age of Ma, and a further tonalitic gneiss had an age of Ma, with one in...

Atmospheric Deposition of Nitrogen to a Caribbean Coastal Zone (Cayo Coco, Cuba): Temporal Trends and Relative Importance as a Nitrogen Source

Nitrogen (N) deposition to the ocean is thought to be increasing worldwide, but the amount of coastal and open ocean measurements is very limited. In this paper, we assess N deposition in the coastal zone of Cayo Coco, in central Cuba, during a multi-annual period (2005–2007). Wet and dry N depositions were estimated based on the NH 4 + and NO x – concentrations in the rain. Cold fronts and troughs, coming from the west, contributed most to rain (41%) and to N deposition, followed by tropical waves and storms coming from the east, which caused 31% of the rain. Average concentrations of NH 4 + and NO x – in the rain were 8.8 and 8.3 μM. NO x – presented a clearly decreasing trend (0.26 μM per month), decreasing by half during 2005–2007. Total N deposition averaged 3.23 kg N ha−1 year−1, similar to that found in Virgin Islands and Puerto Rico, but lower than previously measured in Cuba and in nearby areas of the USA and than model predictions for the oceanic region around Cuba. These low values and the decreasing trend found are attributed to drastic reduction of fossil fuel and fertilizer use in Cuba since 1990. Because land input has decreased even more drastically, deposition seems to be nowadays the most important N source to the coastal zone of Cayo Coco. The δ15N range of seagrass (Thalassia testudinum) and macroalgae (Penicillus dumetosus) in the area (−1.83‰ to 3.02‰ and +1.02‰ to +4.17‰, respectively) sustain that atmospheric sources (deposition and N2 fixation) comprise 70–90% of the N budget.

Synorogenic basins of central Cuba and collision between the Caribbean and North American plates

The synorogenic basins of central Cuba formed in a collision-related system. A tectono-stratigraphic analysis of these basins allows us to distinguish different structural styles along the Central Cuban Orogenic Belt. We recognize three distinct structural domains: (1) the Escambray Metamorphic Complex, (2) the Axial Zone, and (3) the Northern Deformation Belt. The structural evolution of the Escambray Metamorphic Complex includes a latest Cretaceous compressional phase followed by a Palaeogene extensional phase. Contraction created an antiformal stack in a subduction environment, and extension produced exhumation in an intra-arc setting. The Axial Zone was strongly deformed and shortened from the latest Cretaceous to Eocene. Compression occurred in an initial phase and subsequent transpressive deformation took place in the middle Eocene. The Northern Deformation Belt consists of a thin-skinned thrust fault system formed during the Palaeocene to middle Eocene; folding and faulting occurred in a piggyback sequence with tectonic transport towards the NNE. In the Central Cuban Orogenic Belt, some major SW–NE structures are coeval with the Cuban NW–SE striking folds and thrusts, and form tectonic corridors and/or transfer faults that facilitated strain-partitioning regime attending the collision. The shortening direction rotated clockwise during deformation from SSW–NNE to WSW–ENE. The synchronicity of compression in the north with extension in the south is consistent with the opening of the Yucatan Basin; the evolution from compression–extension to transpression is in keeping with the increase in obliquity in the collision between the Caribbean and North American plates.

Late Albian (Early Cretaceous) ammonites from the Provincial Formation of central Cuba

A late Albian ammonite assemblage from the Provincial Formation of Villa Clara Province, Cuba is described. The Provincial Formation is a lithostratigraphic unit of Albian–Cenomanian age extensively exposed in central Cuba and formed within a part of the Caribbean Tethys that was volcanic during the Cretaceous. The formation is mainly composed of calcareous, terrigenous marine, and volcano-sedimentary deposits characterized by a series of micritic limestones intercalated with marls, sandstones, calcareous conglomerates, ash, and tuffaceous material. A rich assemblage of ammonites recovered from the calcareous biomicrites and marls is of late Albian ( Stoliczkaia dispar Zone, Mortoniceras rostratum Subzone) age. The ammonite fauna shows a strong Tethyan affinity, and only a single hoplitid ammonite species was recorded. Although scarce, the first Cuban report of this and other boreal ammonite species now allows precise correlations to be made between Cuba and Albian sediments elsewhere in the world.

Zircon ages, Sr-Nd-Hf isotopic compositions, and geochemistry of granitoids associated with the northern ophiolite melange of Central Cuba: Tectonic implication for Late Cretaceous magmatism in the Northwestern Caribbean

<h3>Abstract</h3> Tuberculosis remains one of the leading causes of death from a single infectious agent, surpassing both AIDS and malaria. In recent years, two bicyclic nitroimidazole drugs, delamanid and pretomanid have been approved to treat this airborne infection. This has spurred a renewed interest in developing new and improved nitroimidazole analogs. We have previously identified a new bicyclic heteroaromatic subclass, the nitroimidazopyrazinones, with substituted analogs showing promising activity against <i>Mycobacterium tuberculosis</i> under both aerobic and hypoxic environments. A second generation of nitroimidazopyrazinones with extended biaryl side chain also possessed good antiparasitic activity against <i>Trypanosoma brucei brucei</i> and <i>Trypanosoma cruzi</i>, suggesting the utility of this new scaffold for development into potential candidates against both tuberculosis and the kinetoplastid parasites which cause neglected tropical diseases. In this study, we further evaluated the properties of nitroimidazopyrazinone derivatives by assessing their selectivity against different mycobacterial species, measuring their reduction potential, and determining the kinetic parameters as substrates of the deazaflavin-dependent nitroreductase (Ddn), which is the activating enzyme of delamanid and pretomanid in <i>M. tuberculosis</i>. We also conducted an <i>in vivo</i> evaluation of a lead compound, MCC8967 that demonstrated a favorable pharmacokinetic profile, with good oral bioavailability and efficacy in an acute <i>M. tuberculosis</i> infection model. Two other promising compounds MCC9481 and MCC9482, with good <i>in vitro</i> activity (IC₅₀ = 0.016 and 0.10 µM, respectively) against <i>T. cruzi</i>, the causative agent for Chagas diseases, were similarly tested for <i>in vivo</i> activity. These compounds also exhibited good oral bioavailability, and transiently reduced the acute-stage parasite burden by &gt;98‒99% at doses of 50 mg/kg once or twice daily, similar to benznidazole at 100 mg/kg once daily. Overall, we have demonstrated that active nitroimidazopyrazinones have potential to be developed as clinical candidates against both tuberculosis and Chagas disease. <h3>Author Summary</h3> Tuberculosis and parasitic infections continue to impose a significant threat to public health and economic growth worldwide. Most of the efforts to control these diseases still rely on drug treatments with limited effectiveness and significant side effects. There is now an urgent need to develop new treatments to combat these infections. Here, we report the <i>in vitro</i> and <i>in vivo</i> profile of a new bicyclic nitroimidazole subclass, namely nitroimidazopyrazinones, against mycobacteria and <i>Trypanosoma cruzi</i>. We found that derivatives with monocyclic side chains are selective against <i>Mycobacterium tuberculosis</i>, the causative agent of tuberculosis, but not active against other nontuberculosis mycobacteria. In an acute mouse model, they were able to reduce the bacterial load in lungs via oral administration. From a biochemistry perspective, we demonstrated that deazaflavin-dependent nitroreductase (Ddn) could act effectively on nitroimidazopyrazinones, indicating the potential of Ddn as an activating enzyme for these new compounds in <i>M. tuberculosis</i>. We also showed that derivatives with extended biaryl side chain were effective in suppressing infection in an acute <i>T. cruzi</i> infected murine model, with satisfactory oral bioavailability. These findings improve the understanding of the biological profile of nitroimidazopyrazinones for further development as potential antitubercular and antiparasitic agents.

Synthesis and Characterization of Organophilic Clay from Cuban Chiqui Gomez Bentonite

Smectites are clay mineral with a layered structure and nanometric thickness, high specific area and a huge variety of uses. Consisting on stacked layers of about 1nm thickness, including two silica tetrahedral and one octahedral sheet. Properties of natural Smectites can be enhanced by organic modification, due to the substitution of the exchangeable cations in the interlayer area. In fact, the properties of the modified smectite (organophilic clay) are related to its modified chemical composition and structural parameters. The interaction of smectite clays with surfactants has an important interest in the fields of drilling fluids, paints, cosmetic, ceramic industries and others. Recent applications are: remediation of contaminated areas and polymer/clay nanocomposites. The aim of this paper is to obtain organophilic clays using a bentonite from the Chiqui Gómez deposit in Central Cuba. The raw and organophilic clays were analyzed by DRX, SEM, swelling capacity in organic solvents and others.

Definitive identification of orange rust of sugarcane caused by Puccinia kuehnii in Cuba

In November 2008, leaf lesions, pale yellow to yellow-orange, sometimes coalescing in large necrotic areas, were observed on hybrid sugarcane clones (Saccharum spp.) CSG 86-504, CSG 24-92, CSG 204-92 and CC 87-409 at the Sugarcane Research Institute (INICA) Station in Villa Clara province, in central Cuba. Specimens were submitted to the Central Plant Quarantine Laboratory for identification. The observed morphological features were consistent with those described for Puccinia kuehnii (Virtudazo et al., 2001; Comstock et al., 2008). Uredinial lesions, variable in size (3–4 mm in length), were generally light brown in colour, but occasionally yellow-orange to cinnamon brown. Hypophyllous uredinia were ellipsoidal to fusiform in shape, distinctly lighter and less uniformly distributed than for P. melanocephala. Urediniospores were mostly obovoid to pyriform, almost ellipsoidal in shape, variable in size, 27·5–55·0 (41·9) × 17·5–37·5 (26·0) μm, echinulate with evenly distributed spines. Walls (orange to light cinnamon brown in colour) were 1–2·5 μm thick, often with a pronounced apical thickening, 3–7 μm (mode 5 μm). Four to five equatorial pores were present. In contrast to P. melanocephala, paraphyses were not visible in stereoscopic views of the uredinia and were absent in most specimens. Telia and teliospores were not observed. Total DNA isolation from symptom-bearing leaves with uredinia was performed according to Lin et al. (2001). A real time PCR was conducted using the SYBR green technique with primers synthesized from exact sequences of ITS1, 5·8S, and ITS2 of the large subunit rDNA region reported in GenBank Accessions EU164549 and EU176009 (Comstock et al., 2008). Results confirmed the identification as P. kuehnii. Previous reports of P. kuehnii in Cuba (Commonwealth Mycological Institute, 1969) were based on misidentifications of P. melanocephala. To the authors’ knowledge, P. kuehnii has not been reported by any diagnostic laboratory in Cuba in the last 30 years. In addition, Cuba was not included in the latest P. kuehnii distribution map (CAB International, 2007). Therefore, this is the first confirmed report of the presence of P. kuehnii in Cuba. The disease has since been found in different localities in the central and eastern regions of Cuba, without any reported economic losses to date.

Environmental and vegetational changes recorded in sedimentary leaf wax n-alkanes across the Cretaceous–Paleogene boundary at Loma Capiro, Central Cuba

The stable carbon isotopic compositions ( δ 13C) and chain-length distribution [ACL and n-C 31/( n-C 29 + n-C 31)] of sedimentary leaf wax n-alkanes were investigated across the Cretaceous–Paleogene (K–Pg) boundary at Loma Capiro, Central Cuba, to reconstruct paleoenvironmental changes that are recorded in terrestrial higher plants. The stratigraphic profiles of the n-alkane δ 13C values show a negative excursion in the lowermost Paleocene, although its magnitude is much smaller (∼ 0.3‰) than the global signals (1.5 to 2.0‰) in the surface ocean-atmospheric carbon reservoir. Relations between the n-alkane δ 13C values and the C 31/(C 29 + C 31) ratios exhibit two different trends, suggesting that our δ 13C records are likely affected by two types of paleoenvironmental factors in addition to the δ 13C variations in the exogenous carbon reservoir. Rare occurrence of terrigenous organic matter that is usually transported by rivers suggests that the n-alkanes at Loma Capiro are likely to have been transported by trade winds, which recorded paleoenvironmental conditions of the northwestern part of the African continent. The n-alkane δ 13C values show a parallel decrease with the ACL and C 31/(C 29 + C 31) values in the first 37,000 yr following the K–Pg boundary. Such decreases are consistent with plant physiological responses to reduced net evaporation, suggesting a possible influence of the impact-induced warm-humid condition in the early Paleocene. In contrast, the n-alkane δ 13C values are negatively correlated with the C 31/(C 29 + C 31) ratios from 40,000 to 67,000 yr after the K–Pg boundary. This time period matches well with that required for the recovery of terrestrial floras from the K–Pg mass extinction to those with diversity equivalent to the late Cretaceous, suggesting that the n-alkane signals are also likely affected by the plant diversification process after the mass extinction.

La pequeña minería del oro en Cuba: historia, metalogenia y perspectiva

The history of gold mining in Cuba has been described in numerous published works; however, it has not been systematized in accordance with the socio-economic developments of the island. Several classifications and conceptual models have been presented on the gold metallogeny in Cuba, but they are not clear and do not plainly reflect the essential attributes that characterize gold mineralization on the island. The aforementioned circumstances justified a historical-descriptive research project based on an exhaustive literature review, and the analysis and interpretation of the available information. Gold mining on the island extends over three historical stages: colonial, neocolonial and revolutionary. Four main metallogenetic episodes for gold formation can be distinguished on the island of Cuba: (i) an Aptian-Campanian stage of mineralization with low- and high-sulfidation Au-Cu porphyries, Au skarns and Au-Ag epithermal deposits; (ii) a late Campanianearly Danian episode that hosts orogenic-type gold mineralization and listvenites; (iii) very prolific Danian-middle Eocene gold mineralization in listvenites in Central Cuba and in Palaeogene volcanic island arc rocks in the southern part of eastern Cuba; and lastly, (iv) an Oligocene-Recent mineralization stage in which surface gossans are produced by the oxidation of sulfide ores and placers. The future of gold mining in Cuba is very attractive, but at a small to medium scale.

A Hidden Window into Cuban History: The Carl Withers Manuscript Collection at New York University

This research note describes the Carl Withers Manuscript Collection (CWMC) held at the University Archives of New York University. A unique and rarely used collection, it includes the ethnographic materials and professional correspondence of U.S. anthropologist Carl Withers and his Cuban collaborator Juan Manuel Picabea. Withers did fieldwork in the rural town of Mayajigua, in central Cuba during the late 1940s and early 1950s, with the assistance of Picabea. The authors of the research note focus on three important components of the CWMC that are particularly relevant to Cuba, the Caribbean, and the intellectual history of anthropology in the region: 1) Withers' fieldnotes; 2) black and white photographs taken by Withers; and 3) the manuscript materials by Picabea. The authors provide some insights into each of these components with examples highlighting the potential of the collection for Cuban and Caribbean Studies.

Degrees of Freedom. Louisiana and Cuba After Emancipation (review)

Reviewed by: Degrees of Freedom. Louisiana and Cuba After Emancipation Richard Blackett Rebecca J. Scott. 2008. Degrees of Freedom. Louisiana and Cuba After Emancipation. Cambridge: Harvard University Press. 365 pp. (Paperback). ISBN 0-674-02759-0. The best thing one can say about Louisiana politics during Reconstruction is that it is Byzantine. Years ago, while I was trying to piece together the activities of a couple of African Americans who had gone to Louisiana in the early years of Reconstruction, I was forced on a number of occasions to thrown up my hands in despair of ever understanding the twist and turns of state politics with its competing governors, unpredictable relations between sympathetic whites and freedmen and, for that matter, the ways gradations of color informed relations among African Americans. After all, I am from the Caribbean and know a thing or two about the effects of color on political and social relations. But even that did not prepare me for Louisiana. Rebecca Scott has come to the rescue; or at least I think I now know more about the strange ways of Louisiana politics at the end of the 19th century. Part of the reason for this new appreciation lies in her commanding comparative analysis of developments of Louisiana and Cuba, two major former sugar-producing slave economies, in the years after the American Civil War and the Cuban Ten Years’ War and the shorter War of Independence. This is comparative history at its best, but one that in the end shows how the struggles in both locations became intertwined at the end of the 19th and the beginning of the 20th centuries with the intervention of the United States in Cuba. In order to make the study [End Page 207] more manageable Scott opts for an extensive examination of a sugar-producing center in each location—the Lafourche basin in Louisiana east and southeast of New Orleans and Central Cuba in the jurisdiction of Cienfuegos—economies based on the brutal coercion of labor. The approach allows her to examine the economic, social and political structures of each location in great detail. But it also provides her an opportunity to ask large questions of small places. Scott’s command of structures is complemented effectively by an appreciation for the stories of the people who lived and struggled to make a better world of freedom for themselves. Scott’s analysis of economic, political, and social developments—the structures—never fails to pay close attention to the stories of the men and women who struggled to make a better world for themselves and those who opposed these efforts at every step of the way. As others such as Eric Foner have shown, African Americans and their Republican allies in Louisiana saw the need for a declaration of rights that far exceeded anything guaranteed by the 14th or 15th Amendments. The 1868 Constitution, for instance, declared that all citizens were entitled to the same “civil, political and public rights.” The attainment and protection of these rights depended on a number of factors: the willingness of the national and state Republican Party to defend them by force if necessary against any attempts by the opposition to reverse these gains; accessibility to land for the freedmen; and the willingness of former slaveholders to accede to the demands for such a revolutionary redistribution of land. In less than 30 years after the adoption of the 1868 Constitution all of these gains had been reversed in the face of violence, murder, and mayhem. This “white supremacist project,” Scott argues, aimed to subordinate black labor, force segregation in public places and to suppress the black vote. Yet in spite of this sustained and overwhelming opposition she points to the many examples of racial cooperation, of efforts of black self determination, of cross-class alliances between the descendants of slaves in the country and artisans and professionals in the city. While the search for freedom in Cuba faced less formidable obstacles in the immediate post emancipation period, by the end of the first decade of the 20th century American intervention both encouraged and facilitated the articulation and adoption of policies that, in many ways, mirrored those of Louisiana...

Palaeomagnetism of the central Cuban Cretaceous Arc sequences and geodynamic implications

A detailed palaeomagnetic study of Cretaceous age volcanic and sedimentary arc rocks from central Cuba has been carried out. Samples from 32 sites (12 localities) were subjected to detailed demagnetisation experiments. Nineteen sites from the Los Paso, Mataguá, Provincial and Cabaiguán Formations yielded high unblocking temperature, dual polarity directions of magnetisation which pass the fold tests with confidence levels of 95% or more and are considered to be primary in origin. The palaeomagnetic inclinations are equivalent to palaeolatitudes of 9°N for the Aptian, 18°N for the Albian. A synfolding remanence identified in 5 sites from the younger Hilario Formation indicates a late Cretaceous remagnetisation at a palaeolatitude of 16°N. Our results are in good agreement with previous palaeogeographic models and provide the first high quality palaeomagnetic data demonstrating the gradual northward movement of the Cretaceous Volcanic Arc throughout the Cretaceous. The declination values obtained all indicate significant and similar amounts of anticlockwise rotation from the oldest sequences studied through to the late Cretaceous remagnetisation. This rotation is most likely related to collision of the arc with the North American plate and transpressional strike slip movement along the northern margin of the Caribbean plate as it progressed eastwards into the large Proto-Caribbean basin.

The geotectonic story of the northwestern branch of the Caribbean Arc: implications from structural and geochronological data of Cuba

Abstract Within the last decade, modern petrological and geochronological methods in combination with detailed studies of the field geology have allowed the reconstruction of tectonic processes in the northwestern part of the Caribbean Plate. The development of an oceanic Proto-Yucatán Basin can be traced from the Late Jurassic to the Mid-Cretaceous. From the Mid-Cretaceous onward, an interaction of this basin with the Caribbean Arc can be observed. Geochronological data prove continuous magmatic activity and generation of HP mineral suites in the Caribbean Arc from the Aptian to the Campanian/Maastrichtian. Magmatism ceased at least in onshore central Cuba at about 75 Ma, probably as the southern edge of the continental Yucatán Block began to interact with the advancing arc system. Similarly, the youngest recorded ages for peak metamorphism of high-pressure metamorphic rocks in Cuba cluster at 70 Ma; rapid uplift/exhumation of these rocks occurred thereafter. After this latest Cretaceous interaction with the southern Yucatán Block, the northern Caribbean Arc was dismembered as it entered the Proto-Yucatán Basin region. Because of the continued NE-directed movement, Proto-Yucatán Basin sediments were accreted to the arc and now form the North Cuban fold and thrust belt. Parts of the island arc have been thrust onto the southern Bahamas Platform along the Eocene suture zone in Cuba. Between the arc's interaction with Yucatán and the Bahamas ( c . 70 to c . 40 Ma), the Yucatán intra-arc basin opened by extreme extension and local seafloor accretion between the Cayman Ridge (still part of Caribbean Plate) and the Cuban frontal arc terranes, the latter of which were kinematically independent of the Caribbean. Although magmatism ceased in central Cuba by 75 Ma, traces of continuing Early Palaeogene arc magmatism have been identified in the Cayman Ridge, suggesting that magmatism may not have ceased in the arc as a whole, but merely shifted south relative to Cuba. If so, a shallowing of the subduction angle during the opening of the Yucatán Basin would be implied. Further, this short-lived (?) Cayman Ridge arc is on tectonic strike with the Palaeogene arc in the Sierra Maestra of Eastern Cuba, suggesting south-dipping subduction zone continuity between the two during the final stages of Cuba–Bahamas closure. After the Middle Eocene, the east–west opening of the Cayman Trough left the present Yucatán Basin and Cuba as part of the North American Plate. The subduction geometry, P–T–t paths of HP rocks in Cuban mélanges, the time of magmatic activity and preliminary palaeomagnetic data support the conclusion that the Great Antillean arc was initiated by intra-oceanic subduction at least 900 km SW of the Yucatán Peninsula in the ancient Pacific. As noted above, the Great Antillean Arc spanned some 70 Ma prior to its Eocene collision with the Bahamas. This is one of the primary arguments for a Pacific origin of the Caribbean lithosphere; there simply was not sufficient space between the Americas, as constrained by Atlantic opening kinematics, to initiate and build the Antillean (and other) arcs in the Caribbean with in situ models.

Can Cuba Change? Ferment in Civil Society

Abstract: Despite the apparent stability of the Castro dictatorship, an internal movement of civic resistance has gradually been gaining strength in Cuba. Opposition organizations as the Varela Project and the Women in White have undertaken important initiatives, and some 3,000 actions of protest and non-cooperation take place every year, mostly in the provinces of eastern and central Cuba. Alienated youth, marginalized non-whites, and oppressed workers represent three potentially explosive sources of cleavage and discontent. By reviving the democratic nationalism associated with the tradition of José Martí, the Cuban movement will be an important factor shaping the future of the country. The opposition within Cuba has become more diverse as well as more unified, and the regime, despite its enduring capacity for repression, is showing signs of underlying weakness.

Emplacement of the northern ophiolites of Cuba and the Campanian-Eocene geological history of the northwestern Caribbean-SE Gulf of Mexico region

Abstract The Mesozoic Proto-Caribbean Plate was consumed in the subduction zone of the Greater Antilles volcanic arc until the Campanian. At this time, volcanic arc magmatism ceased along Cuba. From Late Campanian to Danian, Cuba and its surroundings were a collision zone where the GAC accreted to the North American palaeomargin. In the Danian the almost east–west trending SE Cuba–Cayman Ridge–Hispaniola? volcanic arc was born. The related north dipping subduction zone acted as the SE North American plate boundary. From the Paleocene to Middle Eocene dense Caribbean lithosphere travelled northwards. The location, strike and subduction polarity of the assumed subduction zone are very different from those described by other models. Almost simultaneously the Cuban Orogeny developed in western and central Cuba. During the orogeny the northern ophiolite belt of Cuba and the Cretaceous volcanic rocks were thrust northwards tens of kilometres, onto the Mesozoic North American palaeomargin. In the Middle Eocene subduction stopped. Simultanously(?) a change in the regional stress field originated the near east–west trending sinistral Oriente fault zone, whose position and origin are probably tied to the weakened hot crust to the south of the Palaeogene volcanic arc axis.

Ferment in Civil Society

Abstract: Despite the apparent stability of the Castro dictatorship, an internal movement of civic resistance has gradually been gaining strength in Cuba. Opposition organizations as the Varela Project and the Women in White have undertaken important initiatives, and some 3,000 actions of protest and non-cooperation take place every year, mostly in the provinces of eastern and central Cuba. Alienated youth, marginalized non-whites, and oppressed workers represent three potentially explosive sources of cleavage and discontent. By reviving the democratic nationalism associated with the tradition of José Martí, the Cuban movement will be an important factor shaping the future of the country. The opposition within Cuba has become more diverse as well as more unified, and the regime, despite its enduring capacity for repression, is showing signs of underlying weakness.

GOBERNABILIDAD Y SOSTENIBILIDAD: Reflexiones y retos antes los procesos globales

At present time the environmental conditions have been lashed by diverse socioeconomic, cultural impacts and in certain political causes. The ecosystem at central Cuba, well-known as Escambray or Guamuhaya, in which coffee, livestock, and many other agricultural productions have traditionally been developed biggest results, received influences of modern approaches and models, crossed by urban and global culture, increasing its fragility. So the issues about government and sustainability are closed to these concepts too. From these points of view are built some reflections to explain the relationship among position of the government, decisions maker, and sustainability, taking in account the influences of the global process in human behaviours. It is concluded that isn´t enough the best intentions in actions but it is necessary to joint willingness in a real participatory system and coherent perspective.

Giardiainfections in Cuban children: the genotypes circulating in a rural population

Stool samples containing Giardia duodenalis cysts were collected from 95 primary-school children in central Cuba, and preserved by storing at -20 degrees C in 70% ethanol. Clinical data were collected for each child. Although 57% of the children were asymptomatic, the remaining 43% each reported between one and three symptoms. Following cyst quantification and isolation, molecular analyses were attempted on all cyst isolates, with the focus on the parasite's beta-giardin and glutamate-dehydrogenase (gdh) genes. Unfortunately, the cyst-preservation procedure appeared to have a deleterious effect on the cysts, since genotyping data could only be obtained for 20 of the 95 isolates. These data indicated, however, an approximately equal distribution between assemblage A (nine isolates) and assemblage B (11 isolates). Children found to be excreting relatively large numbers of cysts were more likely to be symptomatic than children who were excreting fewer cysts, and children with Giardia isolates from assemblage B were more likely to have symptomatic infections than children with isolates from assemblage A. Although considerable sequence variability was seen in the assemblage-B isolates, the assemblage-A isolates were relatively genetically homogeneous. This is the first publication from the Caribbean in which the Giardia genotypes circulating within the population have been identified, the first from the Americas providing information on associations between clinical presentation and the assemblage of the infecting Giardia, and the first to indicate that levels of cyst excretion may have clinical significance.