Timing and magnitude of progressive exhumation and deformation associated with Eocene arc-continent collision in the NE Caribbean plate

2020 ◽  
Author(s):  
Y.A. Román ◽  
E.J. Pujols ◽  
A.J. Cavosie ◽  
D.F. Stockli
Keyword(s):  
Puerto Rico ◽  
Time Frame ◽  
Virgin Islands ◽  
Late Eocene ◽  
North American Plate ◽  
Early Eocene ◽  
Caribbean Plate ◽  
The North ◽  
Early Oligocene ◽  
The Caribbean

Puerto Rico and the northern Virgin Islands together preserve a unique archive of island arc construction and plate margin deformation along the northeastern edge of the Caribbean plate. In Eocene times, arc-continent collision of the Caribbean plate and the North American plate led to transpressional deformation along two major fault systems in Puerto Rico, resulting in an island-wide depositional hiatus. Although styles and kinematics of this deformational event are seemingly well understood, the lack of chronologic constraints have left uncertainties related to the timing of inception and activity, the magnitude of crustal exhumation, and the character of deformation (i.e., progressive or polyphase). New zircon and apatite (U-Th)/He ages reveal that deformation associated with arc-continent collision started in the early Eocene (ca. 52 Ma) and ended in the early Oligocene (ca. 29 Ma). Over this 23 m.y. time frame, deformation was not restricted to major faults, instead it propagated gradually eastward, with punctuated episodes of vertical exhumation in the early Eocene (ca. 52−34 Ma) and late Eocene (ca. 36−29 Ma). In contrast, the northern Virgin Islands experienced rapid cooling and exhumation in the early Miocene (ca. 24−21 Ma) associated with the extensional opening of the Anegada Passage. The modeled thermal histories for the central and northeastern part of Puerto Rico indicate collision-related peak transpressional deformation between 36 and 29 Ma and an average exhumation rate 0.9 ± 0.6 km/m.y. These results represent the first direct constraints on the timing and magnitude of collisional exhumation and offer insights into the deformational evolution of the northeastern edge of the Caribbean plate.

Seismic anisotropy beneath the northeastern Caribbean: implications for the subducting North American lithosphere

2013 ◽  
Vol 184 (1-2) ◽  
pp. 67-76 ◽  
Author(s):  
Hallie E. Meighan ◽  
Jay Pulliam
Keyword(s):  
Puerto Rico ◽  
North American ◽  
Seismic Anisotropy ◽  
Plate Boundary ◽  
Virgin Islands ◽  
North American Plate ◽  
Mantle Flow ◽  
British Virgin Islands ◽  
Delay Times ◽  
The Caribbean

Abstract Active plate boundaries in the Caribbean form a complex tectonic environment that includes transform and subduction zones. The Caribbean-North American plate boundary is one such active margin, where subduction transitions from arc- to oblique-type off the northeast coast of Puerto Rico. Understanding mantle flow in this region will not only help determine the nature of tectonic activity and mantle dynamics that control these margins, but will also aid our understanding of the fate of subducting lithosphere. The existence of tears, windows, and gaps in subducting slabs has been proposed at various locations around the world but few have been confirmed. Since mantle flow and crustal deformation are believed to produce seismic anisotropy in the asthenosphere and lithosphere, searching for changes in, for example, SKS splitting parameters can help identify locations at which subducting slabs have been disrupted. Several lines of evidence support the notion of a slab tear within the subducting North American plate at this transition zone, including the counter-clockwise rotation of the Puerto Rico microplate over the past ~10 Ma, clusters of small seismic events, and trench collapse initiating ~3.3 m.y. Here we present results from a detailed investigation of seismic anisotropy from 28 stations across six networks in the Northeast Caribbean that support the hypothesis of a significant slab gap in the vicinity of the U.S. and British Virgin islands. A regional synthesis of our results reveals fast shear wave polarizations that are generally oriented parallel to the plate boundary with intermediate to high SH-SV delay times. For example, polarization directions are oriented roughly NE-SW along the bulk of the Lesser Antilles, E-W along the Puerto Rico trench and the northern Lesser Antilles, and NW-SE beneath Hispaniola. Beneath the U.S. and British Virgin Islands, however, the fast polarization direction differs markedly from the regional pattern, becoming almost perpendicular to the plate boundary. Stations on Anegada, British Virgin islands and St. Croix, U.S. Virgin islands show a fast polarization direction that is oriented nearly NNE-SSW and smaller delay times than surrounding stations. These results suggest that mantle flow is redirected NE-SW at this location through a gap in the subducted lithosphere of the North American plate.

Peridotites and basaltic rocks within an ophiolitic mélange from the SW igneous province of Puerto Rico: relation to the evolution of the Caribbean Plate

2016 ◽  
Vol 154 (1) ◽  
pp. 96-118
Author(s):  
NADJA OMARA CINTRON FRANQUI ◽  
SUNG HI CHOI ◽  
DER-CHUEN LEE
Keyword(s):  
Puerto Rico ◽  
Tectonic Setting ◽  
Geochemical Data ◽  
Transform Fault ◽  
Caribbean Plate ◽  
Basaltic Rocks ◽  
The North ◽  
Ophiolitic Mélange ◽  
Igneous Province ◽  
The Caribbean

AbstractThe geology of Puerto Rico is divided into three regions: the north, central and SW igneous provinces. Characterized by its Jurassic ophiolitic mélange basement, lithology of the SW Igneous Province (SIP) is not related to either of the other two provinces. The ophiolitic mélange is exposed in three peridotite belts: Monte del Estado, Rio Guanajibo and Sierra Bermeja. We present geochemical data to identify the tectonic setting of the SIP peridotite formation and its relation to the evolution of the Caribbean Plate. Comparisons of spinel Cr no. (13–21), Mg no. (63.3–69.6) and TiO2suggest an abyssal peridotite origin; however, only Sierra Bermeja presents high TiO2characteristics of a mid-ocean-ridge-basalt- (MORB-) like melt reaction. Temperatures determined with two-pyroxene geothermometers indicated a cold thermal regime ofc. 800–1050°C, with characteristics of large-offset transform fault abyssal peridotites. The geochemistry and Sr–Nd–Hf–Pb isotopic compositions of basalts within the mélange were also analysed. Las Palmas amphibolites exhibited normal-MORB-like rare earth element (REE) and trace-element patterns, whereas metabasalts and Lower Cajul basalts exhibited island-arc tholeiitic-like patterns. Highly radiogenic Sr isotopes (0.70339–0.70562) of the basalts suggest seawater alteration; however, Pb–Pb and Nd–Hf isotope correlations represent the primary compositions of a Pacific/Atlantic MORB source for the amphibolites, metabasalts and Lower Cajul basalts. We propose that the SIP ophiolitic mélange was formed along a large-offset transform fault, which initiated subduction and preserved both proto-Pacific and proto-Caribbean lithospheric mantle. Younger Upper Cajul basalts exhibited enriched-MORB-like geochemical and isotopic signatures, which can be attributed to a tectonized Caribbean ocean plateau.

Tertiary extension and tilting in the Queen Charlotte Islands, evidence from dyke swarms and their paleomagnetism

1992 ◽  
Vol 29 (9) ◽  
pp. 1878-1898 ◽  
Author(s):  
E. Irving ◽  
J. G. Souther ◽  
J. Baker
Keyword(s):  
North American ◽  
Late Eocene ◽  
North American Plate ◽  
Western Margin ◽  
Queen Charlotte Islands ◽  
The North ◽  
Early Oligocene ◽  
Magnetic Stability ◽  
Transform Margin ◽  
Dyke Swarms

The Queen Charlotte Islands form the western margin of the Tertiary Queen Charlotte Basin, which is situated on the western margin of the North American Plate. They contain seven major dyke swarms of Late Eocene to Miocene age, a period when the relative motions of the Pacific and the North American plates in this region were dominantly dextral strike slip (transform margin), with intervals of highly oblique divergence and convergence. Within each swarm, dykes have a systematic trend. However, trends vary from swarm to swarm, indicating that the stress field varied. A total of 678 cores (1352 specimens) were collected from 129 dykes in six swarms over a distance of about 200 km. Magnetic stability is variable. One hundred and one dykes yielded records of the paleofield. Data are also reported from an Oligocene pluton (5 sites, 27 cores, 52 specimens) and Miocene lavas (8 sites, 52 cores, 101 specimens). Both normal and reversed magnetizations occur, but irrespective of sign, the mean directions of remanent magnetization of each swarm and of the pluton and the lavas have systematically steeper inclinations than the value calculated from coeval rocks in North America. To explain this it is proposed that, after dyke emplacement, the sampling areas were tilted to the north or northwest by amounts that vary between 9 and 16°. Apparently, crustal tilting, similar in magnitude and direction, extended over distances of approximately 200 km. This cannot reflect tilting of a single block. Instead, it is argued that at least the southern Queen Charlotte Islands underwent considerable northerly or north-northwesterly directed extension and normal block faulting, which followed and in part was concurrent with the formation of widespread mid-Tertiary dyke swarms, plutons and lava flows. Making use of the fact that dykes propagate perpendicular to the direction of extension, and combining previously measured dyke orientations with paleomagnetic data, three stages of extension are proposed: east–west extension sometime during the Late Eocene to Early Oligocene; north–south extension sometime in the interval Late Oligocene to Early Miocene; and northwest–southeast extension sometime during Late Miocene or later time.

Geology and hydrogeology of the Caribbean islands aquifer system of the Commonwealth of Puerto Rico and the U.S. Virgin Islands

2002 ◽  
Author(s):  
Robert A. Renken ◽  
W. C. Ward ◽  
I.P. Gill ◽  
Fernando Gómez-Gómez ◽  
Jesús Rodríguez-Martínez ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Virgin Islands ◽  
Aquifer System ◽  
Caribbean Islands ◽  
The Caribbean ◽  
The U.S

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.

Caribbean Organization

1965 ◽  
Vol 19 (4) ◽  
pp. 1070-1073
Keyword(s):  
United States ◽  
Puerto Rico ◽  
The Netherlands ◽  
French Guiana ◽  
The United States ◽  
Virgin Islands ◽  
British Virgin Islands ◽  
Netherlands Antilles ◽  
The United Kingdom ◽  
The Caribbean

The Caribbean Council held its fifth and last meeting in Curaçao, Netherlands Antilles, from November 30 to December 4, 1964. Attending the meeting were delegates from France on behalf of French Guiana, Guadeloupe, and Martinique; the Netherlands Antilles; Surinam; the British Virgin Islands; the Commonwealth of Puerto Rico; and the United States Virgin Islands. Representatives of Antigua, Barbados, Dominica, Grenada, Montserrat, and St. Vincent, countries enjoying special observer status, attended the meeting. Also at the meeting were observers from the Netherlands, the United Kingdom, and the United States.

Grossplots: a Method for Estimating the Temperature State of the Earth and of Australia, Cretaceous to Middle Miocene

1997 ◽  
Vol 45 (3) ◽  
pp. 359 ◽  
Author(s):  
L. A. Frakes
Keyword(s):  
Middle Miocene ◽  
Global Climate ◽  
Interval Data ◽  
Late Eocene ◽  
Space Distribution ◽  
Mean Annual Temperature ◽  
The North ◽  
Early Oligocene ◽  
Time Space ◽  
Temperature State

Grossplots are compilations of globally distributed palaeotemperature data onto latitude versus age plots, which are then contoured. The results specifically show the distribution of temperature over the globe and its variations over the Cretaceous to Middle Miocene interval. Data for continents and oceans are plotted separately in this investigation, and each such grossplot is in accord with the known climate changes of this time. The general scarcity of quantitative palaeotemperature information for Australia can be rectified by deriving, from the global continental grossplot, the relationship between mean annual temperature and latitude. When these are applied to the latitude band progressively occupied by Australia, the following observations can be made: (1) during the Early Cretaceous, the south-east of the continent was subjected to freezing wintertime temperatures; (2) peak warming of northern Australia was attained in the Turonian–Santonian, but this was followed by cooling later in the Cretaceous; (3) Early Tertiary warming until the Late Eocene particularly affected the northern half of the continent, but this region then underwent the most severe cooling in the Early Oligocene; (4) subsequently, the whole of the continent cooled uniformly from conditions only slightly warmer than at present. Despite Australia’s equatorward march, the Late Cretaceous to Palaeocene climates of the continent have been influenced more effectively by changes in the global climate state. However, global cooling since the Eocene has been less effective than drift in controlling the warming climate of Australia. The time–space distribution of precipitation over Australia is estimated from the global relationship between terrestrial temperature and rainfall. The Eocene experienced the heaviest rainfall (> 1560 mm year-1, in the north only), and the Eocene to Middle Miocene experienced moderately high rates (> 500 mm year-1 in the northern three-quarters of the continent). Tertiary brown coals in southern regions were formed in proximity to areas of high rainfall. Continentwide low rates (< 500 mm year-1; semi-arid) are suggested for the Cretaceous, except for wet conditions in the north during the Albian–Santonian and the Late Maastrichtian. Estimates of precipitation are subject to factors such as continentality and location of moisture sources, which cannot be evaluated at present.

Pre-Priabonian Palaeogene formations in southwestern Bulgaria and northern Greece: stratigraphy and tectonic implications

1998 ◽  
Vol 135 (1) ◽  
pp. 101-119 ◽  
Author(s):  
IVAN S. ZAGORCHEV
Keyword(s):  
Late Cretaceous ◽  
Middle Eocene ◽  
Regional Metamorphism ◽  
Late Eocene ◽  
Thin Layers ◽  
The South ◽  
Northern Greece ◽  
The North ◽  
Early Oligocene ◽  
Metamorphic Core

The Paril Formation (South Pirin and Slavyanka Mountains, southwestern Bulgaria) and the Prodromos Formation (Orvilos and Menikion Mountains, northern Greece) consist of breccia and olistostrome built up predominantly of marble fragments from the Precambrian Dobrostan Marble Formation (Bulgaria) and its equivalent Bos-Dag Marble Formation (Greece). The breccia and olistostrome are interbedded with thin layers of calcarenites (with occasional marble pebbles), siltstones, sandstones and limestones. The Paril and Prodromos formations unconformably cover the Precambrian marbles, and are themselves covered unconformably by Miocene and Pliocene sediments (Nevrokop Formation). The rocks of the Paril Formation are intruded by the Palaeogene (Late Eocene–Early Oligocene) Teshovo granitoid pluton, and are deformed and preserved in the two limbs of a Palaeogene anticline cored by the Teshovo pluton (Teshovo anticline). The Palaeocene–Middle Eocene age of the formations is based on these contact relations, and on occasional finds of Tertiary pollen, as well as on correlations with similar formations of the Laki (Kroumovgrad) Group throughout the Rhodope region.The presence of Palaeogene sediments within the pre-Palaeogene Pirin–Pangaion structural zone invalidates the concept of a ‘Rhodope metamorphic core complex’ that supposedly has undergone Palaeogene amphibolite-facies regional metamorphism, and afterwards has been exhumed by rapid crustal extension in Late Oligocene–Miocene times along a regional detachment surface. Other Palaeogene formations of pre-Priabonian (Middle Eocene and/or Bartonian) or earliest Priabonian age occur at the base of the Palaeogene sections in the Mesta graben complex (Dobrinishka Formation) and the Padesh basin (Souhostrel and Komatinitsa formations). The deposition of coarse continental sediments grading into marine formations (Laki or Kroumovgrad Group) in the Rhodope region at the beginning of the Palaeogene Period marks the first intense fragmentation of the mid- to late Cretaceous orogen, in particular, of the thickened body of the Morava-Rhodope structural zone situated to the south of the Srednogorie zone. The Srednogorie zone itself was folded and uplifted in Late Cretaceous time, thus dividing Palaeocene–Middle Eocene flysch of the Louda Kamchiya trough to the north, from the newly formed East Rhodope–West Thrace depression to the south.

The centipede genus Newportia Gervais, 1847, in Mexico: description of a new troglomorphic species; redescription of N. sabina Chamberlin, 1942; revival of N. azteca Humbert & Saussure, 1869; and a summary of the fauna (Scolopendromorpha: Scolopocryptopidae: Newportiinae)

Zootaxa ◽  
2003 ◽  
Vol 379 (1) ◽  
pp. 1 ◽  
Author(s):  
AMAZONAS C. JUNIOR ◽  
ROWLAND M. SHELLEY
Keyword(s):  
Puerto Rico ◽  
Florida Keys ◽  
Virgin Islands ◽  
Distribution Map ◽  
Us Virgin Islands ◽  
British Virgin Islands ◽  
The Third ◽  
The Us ◽  
New Localities ◽  
The Caribbean

In Mexico, the newportiine scolopocryptopid genus Newportia Gervais, 1847, comprises 10 species: N. mexicana (Saussure, 1858); N. azteca Humbert & Saussure, 1869; N. stolli (Pocock, 1896); N. spinipes Pocock, 1896; N. oreina Chamberlin, 1915; N. sabina and pelaezi, both by Chamberlin, 1942; N. atoyaca and morela, both by Chamberlin, 1943, and N. troglobia, n. sp. The last occurs in caves in Tamaulipas and appears to be an obligate troglobite; N. sabina, known only from caves in San Luis Potosi, is redescribed and illustrated. Newportia azteca is revived and returned to its rightful position as the third oldest name in the genus; despite having priority by 27 years, it had been considered to be “the same” as N. spinipes and dropped from nomenclature. Although Newportia and the Newportiinae are not known from the continental United States, they do inhabit the country’s territories in the Caribbean; N. heteropoda Chamberlin, 1918, is reported from Puerto Rico, and N. longitarsis virginiensis Lewis, 1989, is recorded from St. Thomas and St. Croix, US Virgin Islands, and Tortola and Virgin Gorda, British Virgin Islands. The northernmost Mexican record, of N. pelaezi in Nuevo León, is only 96 mi (154 km) south of the US border, suggesting that the taxa may potentially be discovered in the southern periphery of Texas; likewise, rafting from Cuba, where 4–5 species occur, could bring them to the Florida Keys. New localities from Mexico are presented for N. stolli, N. spinipes, N. oreina, N. atoyaca, and N. morela, and ranges are depicted on a distribution map.

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