Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc)

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 e...

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Main Authors: W.T. JOLLY, E.G. LIDIAK, A. DICKIN
Format: Article
Language:English
Published: Universitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB) 2006-01-01
Series:Geologica Acta
Subjects:
Online Access:https://revistes.ub.edu/index.php/GEOACTA/article/view/2012
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author W.T. JOLLY
E.G. LIDIAK
A. DICKIN
author_facet W.T. JOLLY
E.G. LIDIAK
A. DICKIN
author_sort W.T. JOLLY
collection DOAJ
description 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 rare earth element (HREE) arc basalts from intra-oceanic tectonic settings and sediment-rich, high-LREE/HREE types from continental margin arcs, respectively. Isotope and incompatible trace element distribution along a 450 km segment of the arc in the northeast Antilles demonstrates that low-LREE/HREE basalts predominate in Albian 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 of incompatible elements in central Puerto Rico (CPR). Northeastern Antilles basalts have consistently elevated La/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 subducted by the south-dipping Antilles arc system as it swept north-eastward across the Caribbean region and eventually approached the Bahama Banks along the south-eastern fringes of the North American Plate. Trace element mixing models indicate sediment proportions in VI and NEPR were limited, averaging considerably below 1.0%. In comparison sediment content in CPR increased from an average slightly above 1.0% in Albian (~112 Ma) basalts to as high as 8% in Cenomanian (100-94 Ma) types. Hypothetical pre-arc pelagic sedimentary facies in the subducted proto-Atlantic (or proto-Caribbean) basin, included 1) a young, centrally located longitudinal ridge-crest facies, with a thin sediment cover, eventually subducted by VI and NEPR, 2) a slightly older basin-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 during Cenomanian time. Following collision of neighboring Hispaniola with the Bahamas sediment budgets in the northeast Antilles stabilized at moderate levels from 2 to 3%, reflecting widespread subduction of North Atlantic Cretaceous pelagic sediment (AKPS).
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spelling doaj.art-db087d00e3d64c9eb07c72a52aad21512023-10-20T07:12:13ZengUniversitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB)Geologica Acta1696-57282006-01-0141-210.1344/105.000000357Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc)W.T. JOLLY0E.G. LIDIAK1A. DICKIN2Brock UniversityUniversity of PittsburghMcMaster UniversityIsland 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 rare earth element (HREE) arc basalts from intra-oceanic tectonic settings and sediment-rich, high-LREE/HREE types from continental margin arcs, respectively. Isotope and incompatible trace element distribution along a 450 km segment of the arc in the northeast Antilles demonstrates that low-LREE/HREE basalts predominate in Albian 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 of incompatible elements in central Puerto Rico (CPR). Northeastern Antilles basalts have consistently elevated La/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 subducted by the south-dipping Antilles arc system as it swept north-eastward across the Caribbean region and eventually approached the Bahama Banks along the south-eastern fringes of the North American Plate. Trace element mixing models indicate sediment proportions in VI and NEPR were limited, averaging considerably below 1.0%. In comparison sediment content in CPR increased from an average slightly above 1.0% in Albian (~112 Ma) basalts to as high as 8% in Cenomanian (100-94 Ma) types. Hypothetical pre-arc pelagic sedimentary facies in the subducted proto-Atlantic (or proto-Caribbean) basin, included 1) a young, centrally located longitudinal ridge-crest facies, with a thin sediment cover, eventually subducted by VI and NEPR, 2) a slightly older basin-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 during Cenomanian time. Following collision of neighboring Hispaniola with the Bahamas sediment budgets in the northeast Antilles stabilized at moderate levels from 2 to 3%, reflecting widespread subduction of North Atlantic Cretaceous pelagic sediment (AKPS).https://revistes.ub.edu/index.php/GEOACTA/article/view/2012Island arcAntillesCretaceousPelagic sedimentMantle melting.
spellingShingle W.T. JOLLY
E.G. LIDIAK
A. DICKIN
Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc)
Geologica Acta
Island arc
Antilles
Cretaceous
Pelagic sediment
Mantle melting.
title Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc)
title_full Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc)
title_fullStr Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc)
title_full_unstemmed Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc)
title_short Cretaceous to Mid-Eocene pelagic sediment budget in Puerto Rico and the Virgin Islands (northeast Antilles Island arc)
title_sort cretaceous to mid eocene pelagic sediment budget in puerto rico and the virgin islands northeast antilles island arc
topic Island arc
Antilles
Cretaceous
Pelagic sediment
Mantle melting.
url https://revistes.ub.edu/index.php/GEOACTA/article/view/2012
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