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| Natura: | Artículo científico |
| Lingua: | en |
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Universitat de Barcelona
2006
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| Accesso online: | https://www.redalyc.org/articulo.oa?id=50540203 |
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| _version_ | 1866812469543960576 |
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| author | E.G. Lidiak |
| author_facet | E.G. Lidiak |
| contents | Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc) E.G. Lidiak W.T. Jolly A.P. Dickin Ciencias de la Tierra Antilles Island arc Cretaceous Mantle melting Pelagic sediment Island arc basalts (IAB) in the Greater Antilles, dating between Albian and mid-Eocene time (~112 to 45 Ma),consist of an early low-K, primitive island arc (PIA) basalt series and a later, predominantly intermediate calcalkaline(CA) series. The rocks resemble modern sediment-poor, low-light rare earth element (LREE)/heavy rareearth element (HREE) arc basalts from intra-oceanic tectonic settings and sediment-rich, high-LREE/HREEtypes from continental margin arcs, respectively. Isotope and incompatible trace element distribution along a450 km segment of the arc in the northeast Antilles demonstrates that low-LREE/HREE basalts predominate inAlbian to Santonian (~85 Ma) stratigraphic sequences in the Virgin Islands (VI) and northeast Puerto Rico(NEPR), while there is a gradual but spectacular increase in both LREE/HREE and absolute abundances ofincompatible elements in central Puerto Rico (CPR). Northeastern Antilles basalts have consistently elevatedLa/Nb and relatively low Nb/Zr, both inconsistent with the presence of a significant ocean island basalt component.Hence, observed differences are interpreted to reflect variation in proportions of pelagic sediment subductedby the south-dipping Antilles arc system as it swept north-eastward across the Caribbean region and eventuallyapproached the Bahama Banks along the south-eastern fringes of the North American Plate. Trace elementmixing models indicate sediment proportions in VI and NEPR were limited, averaging considerably below1.0%. In comparison sediment content in CPR increased from an average slightly above 1.0% in Albian (~112Ma) basalts to as high as 8% in Cenomanian (100-94 Ma) types. Hypothetical pre-arc pelagic sedimentaryfacies in the subducted proto-Atlantic (or proto-Caribbean) basin, included 1) a young, centrally located longitudinalridge-crest facies, with a thin sediment cover, eventually subducted by VI and NEPR, 2) a slightly olderbasin-margin facies of variable width and moderate sediment thickness, subducted by CPR during Albian time,and 3) a thick, pre-arc continental margin facies in the vicinity of Central America, subducted by CPR duringCenomanian time. Following collision of neighboring Hispaniola with the Bahamas sediment budgets in thenortheast Antilles stabilized at moderate levels from 2 to 3%, reflecting widespread subduction of NorthAtlantic Cretaceous pelagic sediment (AKPS). 2006 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50540203 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.1-2 Vol.4 |
| format | Artículo científico |
| id | redalyc_50540203 |
| language | en |
| publishDate | 2006 |
| publisher | Universitat de Barcelona |
| spellingShingle | Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc) E.G. Lidiak Ciencias de la Tierra Antilles Island arc Cretaceous Mantle melting Pelagic sediment Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc) E.G. Lidiak W.T. Jolly A.P. Dickin Ciencias de la Tierra Antilles Island arc Cretaceous Mantle melting Pelagic sediment Island arc basalts (IAB) in the Greater Antilles, dating between Albian and mid-Eocene time (~112 to 45 Ma),consist of an early low-K, primitive island arc (PIA) basalt series and a later, predominantly intermediate calcalkaline(CA) series. The rocks resemble modern sediment-poor, low-light rare earth element (LREE)/heavy rareearth element (HREE) arc basalts from intra-oceanic tectonic settings and sediment-rich, high-LREE/HREEtypes from continental margin arcs, respectively. Isotope and incompatible trace element distribution along a450 km segment of the arc in the northeast Antilles demonstrates that low-LREE/HREE basalts predominate inAlbian to Santonian (~85 Ma) stratigraphic sequences in the Virgin Islands (VI) and northeast Puerto Rico(NEPR), while there is a gradual but spectacular increase in both LREE/HREE and absolute abundances ofincompatible elements in central Puerto Rico (CPR). Northeastern Antilles basalts have consistently elevatedLa/Nb and relatively low Nb/Zr, both inconsistent with the presence of a significant ocean island basalt component.Hence, observed differences are interpreted to reflect variation in proportions of pelagic sediment subductedby the south-dipping Antilles arc system as it swept north-eastward across the Caribbean region and eventuallyapproached the Bahama Banks along the south-eastern fringes of the North American Plate. Trace elementmixing models indicate sediment proportions in VI and NEPR were limited, averaging considerably below1.0%. In comparison sediment content in CPR increased from an average slightly above 1.0% in Albian (~112Ma) basalts to as high as 8% in Cenomanian (100-94 Ma) types. Hypothetical pre-arc pelagic sedimentaryfacies in the subducted proto-Atlantic (or proto-Caribbean) basin, included 1) a young, centrally located longitudinalridge-crest facies, with a thin sediment cover, eventually subducted by VI and NEPR, 2) a slightly olderbasin-margin facies of variable width and moderate sediment thickness, subducted by CPR during Albian time,and 3) a thick, pre-arc continental margin facies in the vicinity of Central America, subducted by CPR duringCenomanian time. Following collision of neighboring Hispaniola with the Bahamas sediment budgets in thenortheast Antilles stabilized at moderate levels from 2 to 3%, reflecting widespread subduction of NorthAtlantic Cretaceous pelagic sediment (AKPS). 2006 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50540203 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.1-2 Vol.4 |
| title | Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc) |
| topic | Ciencias de la Tierra Antilles Island arc Cretaceous Mantle melting Pelagic sediment |
| url | https://www.redalyc.org/articulo.oa?id=50540203 |