K-Ar geochronology and palaeomagnetism of volcanic rocks in the Lesser Antilles island arc

Briden, J. C.; Rex, D. C.; Faller, A.; Tomblin, J. F.

doi:10.1098/rsta.1979.0040

Cited by 162 publications

(51 citation statements)

References 15 publications

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“…Volcanic activity occurred during the Pliocene with the extrusion of basaltic to andesitic lavas cut by dykes (5.0-3.5 Ma Briden et al 1979). Three formations have been identified, corresponding to sequential phases of sometimes concurrent volcanism ( Fig.…”

Section: Geological Settingmentioning

confidence: 99%

Magma evolution beneath Bequia, Lesser Antilles, deduced from petrology of lavas and plutonic xenoliths

Camejo-Harry

Melekhova

Blundy

et al. 2018

Contrib Mineral Petrol

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General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms Vol.:(0123456789) 1 3Contributions to Mineralogy and Petrology (2018) AbstractExtrusive and intrusive igneous rocks represent different parts of a magmatic system and ultimately provide complementary information about the processes operating beneath volcanoes. To shed light on such processes, we have examined and quantified the textures and mineral compositions of plutonic and cumulate xenoliths and lavas from Bequia, Lesser Antilles arc. Both suites contain assemblages of iddingsitized olivine, plagioclase, clinopyroxene and spinel with rare orthopyroxene and ilmenite. Mineral zoning is widespread, but more protracted in lavas than xenoliths. Plagioclase cores and olivine have high anorthite (An ≤ 98) and low forsterite (Fo ≤ 84) compositions respectively, implying crystallisation from a hydrous mafic melt that was already fractionated. Xenolith textures range from adcumulate to orthocumulate with variable mineral crystallisation sequences. Textural criteria are used to organize the xenoliths into six groups. Amphibole, notably absent from lavas, is a common feature of xenoliths, together with minor biotite and apatite. Bulk compositions of xenoliths deviate from the liquid line of descent of lavas supporting a cumulate origin with varying degrees of reactive infiltration by evolved hydrous melts, preserved as melt inclusions in xenolith crystals. Volatile saturation pressures in melt inclusions indicate cumulate crystallization over a 162-571 MPa pressure range under conditions of high dissolved water contents (up to 7.8 wt% H 2 O), consistent with a variety of other thermobarometric estimates. Phase assemblages of xenoliths are consistent with published experimental data on volatile-saturated low-magnesium and high-alumina basalts and basaltic andesite from the Lesser Antilles at pressures of 200-1000 MPa, temperatures of 950-1050 °C and dissolved H 2 O contents of 4-7 wt%. Once extracted from mid-crustal mushes, residual melts ascend to higher levels and undergo H 2 O-saturated crystallization in shallow, preeruptive reservoirs to form phenocrysts and glomerocrysts. The absence of amphibole from lavas reflects instability at low pressures, whereas its abundance in xenoliths testifies to its importance in mid-crustal differentiation processes. A complex, vertically extensive (6 to at least 21 km depth) magmatic system is inferred beneath Bequia. Xenoliths represent fragments of the mush incorporated into ascending magmas. The widespread occurrence of evolved melts in the mush, but the absence of erupted evolved magmas, in contrast to islands in the northern Lesser Antilles, may reflect the relative immaturity of the Bequia magmatic system.

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Section: Geological Settingmentioning

confidence: 99%

Magma evolution beneath Bequia, Lesser Antilles, deduced from petrology of lavas and plutonic xenoliths

Camejo-Harry

Melekhova

Blundy

et al. 2018

Contrib Mineral Petrol

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“…CaribbeanAmerican relative motion was recorded by (1) opening of the Cayman Trough pull-apart basin [note: Cayman Trough magnetic anomalies (Rosencrantz et al 1988;Leroy et al 2000;ten Brink et al 2002) may record the basement fault fabric rather than/in addition to seafloor spreading anomalies, but nevertheless they strike northsouth over some 900 -1000 km, making a northsouth opening direction highly unlikely]; (2) Eocene and younger Lesser Antillean arc magmatism (Briden et al 1979); (3) the eastward migration of arc magmatism in SW Mexico as the motion of Chortís exposed that margin to subduction (Pindell et al 1988;Schaaf et al 1995;Ferrari et al 1999); (4) the migrating Caribbean foredeep along northern South America (Dewey & Pindell 1986;Fig. 19); (5) the progressive collision and closure between the trailing edge of Caribbean lithosphere (Panama) and Colombia (Keigwin 1978;Pindell et al 1998;); and (6) the transcurrent separation of northern Hispaniola from Cuba, and the transpressional assembly of the Hispaniolan terranes, along eastward strands of the Cayman Trough transform system (Pindell et al 1988Iturralde-Vinent & McPhee 1999).…”

Section: Eocene -Middle Miocene Transcurrence and Oblique Collision Amentioning

confidence: 99%

Tectonic evolution of the Gulf of Mexico, Caribbean and northern South America in the mantle reference frame: an update

Pindell

Kennan²

2009

576

627

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We present an updated synthesis of the widely accepted 'single-arc Pacific-origin' and 'Yucatán-rotation' models for Caribbean and Gulf of Mexico evolution, respectively. Fourteen palaeogeographic maps through time integrate new concepts and alterations to earlier models. Pre-Aptian maps are presented in a North American reference frame. Aptian and younger maps are presented in an Indo-Atlantic hot spot reference frame which demonstrates the surprising simplicity of Caribbean-American interaction. We use the Müller et al. (Geology 21: 275-278, 1993) reference frame because the motions of the Americas are smoothest in this reference frame, and because it does not differ significantly, at least since c. 90 Ma, from more recent 'moving hot spot' reference frames. The Caribbean oceanic lithosphere has moved little relative to the hot spots in the Cenozoic, but moved north at c. 50 km/Ma during the Cretaceous, while the American plates have drifted west much further and faster and thus are responsible for most CaribbeanAmerican relative motion history. New or revised features of this model, generally driven by new data sets, include: (1) refined reconstruction of western Pangaea; (2) refined rotational motions of the Yucatán Block during the evolution of the Gulf of Mexico; (3) an origin for the Caribbean Arc that invokes Aptian conversion to a SW-dipping subduction zone of a trans-American plate boundary from Chortís to Ecuador that was part sinistral transform (northern Caribbean) and part pre-existing arc (eastern, southern Caribbean); (4) acknowledgement that the Caribbean basalt plateau may pertain to the palaeo-Galapagos hot spot, the occurrence of which was partly controlled by a Proto-Caribbean slab gap beneath the Caribbean Plate; (5) Campanian initiation of subduction at the Panama-Costa Rica Arc, although a sinistral transform boundary probably pre-dated subduction initiation here; (6) inception of a north-vergent crustal inversion zone along northern South America to account for Cenozoic convergence between the Americas ahead of the Caribbean Plate; (7) a fan-like, asymmetric rift opening model for the Grenada Basin, where the Margarita and Tobago footwall crustal slivers were exhumed from beneath the southeast Aves Ridge hanging wall; (8) an origin for the Early Cretaceous HP/LT metamorphism in the El Tambor units along the Motagua Fault Zone that relates to subduction of Farallon crust along western Mexico (and then translated along the trans-American plate boundary prior to onset of SW-dipping subduction beneath the Caribbean Arc) rather than to collision of Chortis with Southern Mexico; (9) Middle Miocene tectonic escape of Panamanian crustal slivers, followed by Late Miocene and Recent eastward movement of the 'Panama Block' that is faster than that of the Caribbean Plate, allowed by the inception of east-west trans-Costa Rica shear zones. The updated model integrates new concepts and global plate motion models in an internally consistent way, and can be used to test and guide more local ...

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“…The migration of the Northern Barbados Ridge is related to the evolution of the Caribbean area, that can be defined as a relative motion of about 1100 km in an approximately eastward direction since the Eocene with respect the North America plate [Briden et al, 1979;Pindell et al, 1988;Pindell and Barrett, 1990].…”

Section: Geological Setting Of Northern Barbados Ridge and Apenninesmentioning

confidence: 99%

Décollement depth versus accretionary prism dimension in the Apennines and the Barbados

et al. 2003

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Along representative cross sections of the Apennines and the Northern Barbados accretionary prisms, we measured the area, the décollement depth, the angle α of the upper envelope and the angle β of the dip of the regional monocline. The continental sections of the Apennines accretionary prism have a deeper décollement than the oceanic sections of the Northern Barbados, 6–10 km depth and <1 km depth, respectively, because the sediment pile is thinner on the incoming Barbados plate and its denser oceanic structure is more easily subducted. Considering the frontal 50 km, the Apennines have an average cross‐sectional area of 500 km2 and the Northern Barbados Ridge of 100 km2. The total area is a function of the depth of the décollement plane. Therefore, at a given amount of subduction, the deeper the décollement depth is, the bigger the area of the wedge will result, assuming negligible compaction and erosion. As a consequence, the larger area/volume and higher elevation of the Apennines with respect to the Barbados is determined by the Apenninic deeper décollement. Despite these differences, the geometry of both décollements is, in some cases, comparable, in particular, close to the boundary between the crystalline crust and the sediment pile, where the main density and strength contrasts are concentrated. Variations in depth of the décollement occur moving along strike in both accretionary prisms. The geometry of the prisms is further controlled by the different values of α and β, their sum, and the distance of the accretionary prism relative to the subduction hinge.

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K-Ar geochronology and palaeomagnetism of volcanic rocks in the Lesser Antilles island arc

Cited by 162 publications

References 15 publications

Magma evolution beneath Bequia, Lesser Antilles, deduced from petrology of lavas and plutonic xenoliths

Magma evolution beneath Bequia, Lesser Antilles, deduced from petrology of lavas and plutonic xenoliths

Tectonic evolution of the Gulf of Mexico, Caribbean and northern South America in the mantle reference frame: an update

Décollement depth versus accretionary prism dimension in the Apennines and the Barbados

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