Magmatic relationships and ages between adakites, magnesian andesites and Nb-enriched basalt-andesites from Hispaniola: Record of a major change in the Caribbean island arc magma sources

Lithos ◽  
2007 ◽  
Vol 99 (3-4) ◽  
pp. 151-177 ◽  
Author(s):  
J. Escuder Viruete ◽  
F. Contreras ◽  
G. Stein ◽  
P. Urien ◽  
M. Joubert ◽  
...  
Keyword(s):  
Major Change ◽  
Island Arc ◽  
Caribbean Island ◽  
Magma Sources ◽  
The Caribbean ◽  
Arc Magma

scholarly journals The Imbert Formation of northern Hispaniola: a tectono-sedimentary record of arc-continent collision and ophiolite emplacement in the northern Caribbean subduction-accretionary prism

2015 ◽  
Vol 7 (2) ◽  
pp. 1827-1876 ◽  
Author(s):  
J. Escuder-Viruete ◽  
A. Suárez-Rodríguez ◽  
J. Gabites ◽  
A. Pérez-Estaún
Keyword(s):  
Subduction Zone ◽  
Continental Margin ◽  
Middle Eocene ◽  
Accretionary Prism ◽  
Island Arc ◽  
Caribbean Island ◽  
Stratigraphic Sequence ◽  
Oblique Collision ◽  
The Caribbean ◽  
Ophiolitic Complex

Abstract. In northern Hispaniola, the Imbert Formation (Fm) has been interpreted as an orogenic "mélange" originally deposited as trench-fill sediments, an accretionary (subduction) complex formed above a SW-dipping subduction zone, or the sedimentary result of the early oblique collision of the Caribbean plate with the Bahama Platform in the middle Eocene. However, new stratigraphical, structural, geochemical and geochronological data from northern Hispaniola indicate that the Imbert Fm constitutes a coarsening-upward stratigraphic sequence that records the transition of the sedimentation from a pre-collisional forearc to a syn-collisional piggy-back basin. This piggy-back basin was transported on top of the Puerto Plata ophiolitic complex slab and structurally underlying accreted units of the Rio San Juan complex, as it was emplaced onto the North America continental margin units. The Imbert Fm unconformably overlies different structural levels of the Caribbean subduction-accretionary prism, including a supra-subduction zone ophiolite, and consists of three laterally discontinuous units that record the exhumation of the underlying basement. The distal turbiditic lower unit includes the latest volcanic activity of the Caribbean island arc; the more proximal turbiditic intermediate unit is moderately affected by syn-sedimentary faulting; and the upper unit is a (caotic) olistostromic unit, composed of serpentinite-rich polymictic breccias, conglomerates and sandstones, strongly deformed by syn-sedimentary faulting, slumping and sliding processes. The Imbert Fm is followed by subsidence and turbiditic deposition of the overlying El Mamey Group. The 40Ar / 39Ar plagioclase plateau ages obtained in gabbroic rocks from the Puerto Plata ophiolitic complex indicate its exhumation at ∼ 45–40 Ma (lower-to-middle Eocene), contemporaneously to the sedimentation of the overlying Imbert Fm. These cooling ages imply the uplift to the surface and submarine erosion of the complex to be the source of the ophiolitic fragments in the Imbert Fm, during of shortly after the emplacement of the intra-oceanic Caribbean island-arc onto the continental margin.

scholarly journals The Imbert Formation of northern Hispaniola: a tectono-sedimentary record of arc–continent collision and ophiolite emplacement in the northern Caribbean subduction–accretionary prism

Solid Earth ◽  
2016 ◽  
Vol 7 (1) ◽  
pp. 11-36 ◽  
Author(s):  
J. Escuder-Viruete ◽  
Á. Suárez-Rodríguez ◽  
J. Gabites ◽  
A. Pérez-Estaún
Keyword(s):  
Subduction Zone ◽  
Continental Margin ◽  
Middle Eocene ◽  
Accretionary Prism ◽  
Island Arc ◽  
Caribbean Island ◽  
Stratigraphic Sequence ◽  
Oblique Collision ◽  
The Caribbean ◽  
Ophiolitic Complex

Abstract. In northern Hispaniola, the Imbert Formation (Fm) has been interpreted as an orogenic “mélange” originally deposited as trench-fill sediments, an accretionary (subduction) complex formed above a SW-dipping subduction zone, or the sedimentary result of the early oblique collision of the Caribbean plate with the Bahama Platform in the middle Eocene. However, new stratigraphical, structural, geochemical and geochronological data from northern Hispaniola indicate that the Imbert Fm constitutes a coarsening-upward stratigraphic sequence that records the transition of the sedimentation from a pre-collisional forearc to a syn-collisional basin. This basin was transported on top of the Puerto Plata ophiolitic complex slab and structurally underlying accreted units of the Rio San Juan complex, as it was emplaced onto the North America continental margin units.The Imbert Fm unconformably overlies different structural levels of the Caribbean subduction-accretionary prism, including a supra-subduction zone ophiolite, and consists of three laterally discontinuous units that record the exhumation of the underlying basement. The distal turbiditic lower unit includes the latest volcanic activity of the Caribbean island arc; the more proximal turbiditic intermediate unit is moderately affected by syn-sedimentary faulting; and the upper unit is a (chaotic) olistostromic unit, composed of serpentinite-rich polymictic breccias, conglomerates and sandstones, strongly deformed by syn-sedimentary faulting, slumping and sliding processes. The Imbert Fm is followed by subsidence and turbiditic deposition of the overlying El Mamey Group.The 40Ar ∕ 39Ar plagioclase plateau ages obtained in gabbroic rocks from the Puerto Plata ophiolitic complex indicate its exhumation at  ∼  45–40 Ma (lower-to-middle Eocene), contemporaneously to the sedimentation of the overlying Imbert Fm. These cooling ages imply the uplift to the surface and submarine erosion of the complex to be the source of the ophiolitic fragments in the Imbert Fm, during or shortly after the emplacement of the intra-oceanic Caribbean island arc onto the continental margin.

An ecological shift in a remote coral atoll of Belize over 25 years

1998 ◽  
Vol 25 (2) ◽  
pp. 122-130 ◽  
Author(s):  
TIMOTHY R. McCLANAHAN ◽  
NYAWIRA A. MUTHIGA
Keyword(s):  
Central America ◽  
Major Change ◽  
Acropora Cervicornis ◽  
Hard Coral ◽  
Population Densities ◽  
Herbivorous Fishes ◽  
Patch Reefs ◽  
The Past ◽  
Algal Abundance ◽  
The Caribbean

Many coral reefs in the Caribbean, and elsewhere, have undergone changes from hard coral to fleshy algal dominance over the past two decades which has often been interpreted as a localized response to eutrophication and fishing. Here, data on the abundance of hard corals and algae from lagoonal patch reefs distributed throughout a large (260 km2) remote reef atoll located approximately 30 km offshore from the sparsely-populated coast of Belize, Central America, are compared with a study of these patch reefs conducted 25 years previously. Data and observations indicate that these patch reefs have undergone a major change in their ecology associated with a 75% reduction in total hard coral, a 99% loss in the cover of Acropora cervicornis and A. palmata, and a 315% increase in algae, which are mostly erect brown algae species in the genera Lobophora, Dictyota, Turbinaria and Sargassum. Such changes have been reported from other Caribbean reefs during the 1980s, but not on such a remote reef and the present changes may be attributed primarily to both a disease that began killing Acropora in this region in the mid 1980s and a reduction in herbivory. The low level of herbivory may be attributable to the disease-induced loss of the sea urchin Diadema antillarum in 1983, or fishing of herbivorous fishes, but both explanations are speculative. The present density of fisherfolk is low, and their efforts are not targetted at herbivorous fishes, and population densities of D. antillarum 14 years after the mortality are <1 individual per 1000 m2, but there is no comparative data from before the die off. There is, however, no indication that these major changes occurred on the fore reef, because A. palmata is abundant and erect algal abundance is low. We suggest that reported changes in other Caribbean reefs are not necessarily or exclusively influenced by local human factors such as localized intense eutrophication or fishing.

Solar Radiation Over the Caribbean Island of Puerto Rico

Solar Energy ◽  
2004 ◽  
Author(s):  
Ramiro L. Rivera ◽  
Karim Altaii
Keyword(s):  
Puerto Rico ◽  
Solar Radiation ◽  
Global Radiation ◽  
Global Solar Radiation ◽  
Time Frame ◽  
Daily Basis ◽  
Caribbean Island ◽  
Monthly Average ◽  
Energy Conversion System ◽  
The Caribbean

Solar radiation was measured and recorded on a 5-minute, hourly and daily basis at a number of sites on the Caribbean island of Puerto Rico (located from 18° to 18° 30’N latitude and from 65° 30’ to 67° 15’W longitude) over a 24 calendar month time frame. The global solar radiation was measured at four sites (namely: Aguadilla, Ponce, Gurabo, and San Juan). The global solar radiation data was measured by an Eppley Precision Spectral Pyranometer (model PSP) mounted on a horizontal surface. This pyranometer is sensitive to solar radiation in the range of 0.285 ≤ λ ≤ 2.8 μm wavelengths. Statistical analysis such as the daily average, monthly average hourly, monthly average daily, and annual average daily global radiation are presented in this paper. Despite its small size, a 13 percent variation in the global solar radiation has been observed within the island. Reasonable solar radiation values, for solar energy conversion system installation, seem to exist at and possibly around Aguadilla.

Seed Plant Genera Endemic to the Caribbean Island Biodiversity Hotspot: A Review and a Molecular Phylogenetic Perspective

2007 ◽  
Vol 73 (3) ◽  
pp. 183-234 ◽  
Author(s):  
Javier Francisco-Ortega ◽  
Eugenio Santiago-Valentín ◽  
Pedro Acevedo-Rodríguez ◽  
Carl Lewis ◽  
John Pipoly ◽  
...  
Keyword(s):  
Biodiversity Hotspot ◽  
Seed Plant ◽  
Caribbean Island ◽  
Molecular Phylogenetic ◽  
Island Biodiversity ◽  
Phylogenetic Perspective ◽  
The Caribbean

Two new species of flattie spiders (Araneae: Selenopidae) and descriptions of undescribed males from the Caribbean

Zootaxa ◽  
2018 ◽  
Vol 4446 (1) ◽  
pp. 125
Author(s):  
SARAH C. CREWS
Keyword(s):  
New Species ◽  
Dominican Republic ◽  
Endemic Species ◽  
New Records ◽  
Caribbean Island ◽  
Two New Species ◽  
The Caribbean

Two new species of Selenops, S. anacaona sp. nov. (♀) and S. caonabo sp. nov. (♀), are described from the Dominican Republic on the Caribbean island of Hispaniola. These two new species increase the number of endemic Selenops on Hispaniola to 13, surpassing Cuba, which currently has 11 endemic species. Additionally, the male of S. pensilis Muma, 1953 from Hispaniola is described, as well as the male of S. petrunkevitchi Alayón, 2003 from Jamaica. Full distribution records are given for the new species and the newly described males, and new records are provided for the following species: S. aequalis Franganillo, 1935, S. bocacandensis Crews, 2011, S. candidus Muma, 1953, S. micropalpus Muma, 1953, S. morro Crews, 2011, S. simius Muma, 1953, S. souliga Crews, 2011, and S. submaculosus Bryant, 1940. 

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