Ancient xenocrystic zircon in young volcanic rocks of the southern Lesser Antilles island arc

Yamirka ROJAS-AGRAMONTE*, Ian S. WILLIAMS, Richard ARCULUS, Alfred KRÖNER, Antonio GARCÍA-CASCO, Concepción LÁZARO, Stephan BUHRE, Jean WONG, Helen GENG, Carlos Morales ECHEVERRÍA, Teresa JEFFRIES, Hangqian XIE, Regina MERTZ-KRAUS

*Corresponding author for this work

Research output: Journal PublicationsJournal Article (refereed)

7 Citations (Scopus)

Abstract

The Lesser Antilles arc is one of the best global examples in which to examine the effects of the involvement of subducted sediment and crustal assimilation in the generation of arc crust. Most of the zircon recovered in our study of igneous and volcaniclastic rocks from Grenada and Carriacou (part of the Grenadines chain) is younger than 2 Ma. Within some late Paleogene to Neogene (~ 34–0.2 Ma) lavas and volcaniclastic sediments however, there are Paleozoic to Paleoarchean (~ 250–3469 Ma) xenocrysts, and Late Jurassic to Precambrian zircon (~ 158–2667 Ma) are found in beach and river sands. The trace element characteristics of zircon clearly differentiate between different types of magmas generated in the southern Lesser Antilles through time. The zircon population from the younger arc (Miocene, ~ 22–19 Ma, to Present) has minor negative Eu anomalies, well-defined positive Ce anomalies, and a marked enrichment in heavy rare earth elements (HREE), consistent with crystallization from very oxidized magmas in which Eu 2 + was in low abundance. In contrast, zircon from the older arc (Eocene to mid-Oligocene, ~ 30–28 Ma) has two different REE patterns: 1) slight enrichment in the light (L)REE, small to absent Ce anomalies, and negative Eu anomalies and 2) enriched High (H)REE, positive Ce anomalies and negative Eu anomalies (a similar pattern is observed in the xenocrystic zircon population). The combination of positive Ce and negative Eu anomalies in the zircon population of the older arc indicates crystallization from magmas that were variably, but considerably less oxidized than those of the younger arc. All the igneous zircon has positive εHf(t), reflecting derivation from a predominantly juvenile mantle source. However, the εHf(t) values vary significantly within samples, reflecting considerable Hf isotopic heterogeneity in the source. The presence of xenocrystic zircon in the southern Lesser Antilles is evidence for the assimilation of intra-arc crustal sediments and/or the recycling and incorporation of sediments into the magma sources in the mantle wedge. Most likely however, primitive magmas stalling and fractionating during their ascent through the Antilles crust entrained ancient zircon. This is evidence by the geochemistry of the study samples, which is inconsistent with any involvement of partially melted subducted sediment. Paleogeographic reconstructions show that the old zircon could derive from distant regions such as the Eastern Andean Cordillera of Colombia, the Merida Andes, and the northern Venezuela coastal ranges, transported for example by the Proto-Maracaibo River precursor of the Orinoco River.

Original languageEnglish
Pages (from-to)228-252
Number of pages25
JournalLithos
Volume290-291
Early online date17 Aug 2017
DOIs
Publication statusPublished - Oct 2017
Externally publishedYes

Fingerprint

Volcanic rocks
island arc
volcanic rock
zircon
anomaly
Sediments
rare earth element
sediment
Rivers
Crystallization
crystallization
young
river
crust
Geochemistry
Trace Elements
Beaches
Rare earth elements
cordillera
mantle source

Keywords

  • Th disequilibrium
  • Carriacou-Petite Martinique
  • Crustal assimilation
  • Grenada
  • Lesser Antilles
  • Zircon xenocryst

Cite this

ROJAS-AGRAMONTE, Y., WILLIAMS, I. S., ARCULUS, R., KRÖNER, A., GARCÍA-CASCO, A., LÁZARO, C., ... MERTZ-KRAUS, R. (2017). Ancient xenocrystic zircon in young volcanic rocks of the southern Lesser Antilles island arc. Lithos, 290-291, 228-252. https://doi.org/10.1016/j.lithos.2017.08.002
ROJAS-AGRAMONTE, Yamirka ; WILLIAMS, Ian S. ; ARCULUS, Richard ; KRÖNER, Alfred ; GARCÍA-CASCO, Antonio ; LÁZARO, Concepción ; BUHRE, Stephan ; WONG, Jean ; GENG, Helen ; ECHEVERRÍA, Carlos Morales ; JEFFRIES, Teresa ; XIE, Hangqian ; MERTZ-KRAUS, Regina. / Ancient xenocrystic zircon in young volcanic rocks of the southern Lesser Antilles island arc. In: Lithos. 2017 ; Vol. 290-291. pp. 228-252.
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abstract = "The Lesser Antilles arc is one of the best global examples in which to examine the effects of the involvement of subducted sediment and crustal assimilation in the generation of arc crust. Most of the zircon recovered in our study of igneous and volcaniclastic rocks from Grenada and Carriacou (part of the Grenadines chain) is younger than 2 Ma. Within some late Paleogene to Neogene (~ 34–0.2 Ma) lavas and volcaniclastic sediments however, there are Paleozoic to Paleoarchean (~ 250–3469 Ma) xenocrysts, and Late Jurassic to Precambrian zircon (~ 158–2667 Ma) are found in beach and river sands. The trace element characteristics of zircon clearly differentiate between different types of magmas generated in the southern Lesser Antilles through time. The zircon population from the younger arc (Miocene, ~ 22–19 Ma, to Present) has minor negative Eu anomalies, well-defined positive Ce anomalies, and a marked enrichment in heavy rare earth elements (HREE), consistent with crystallization from very oxidized magmas in which Eu 2 + was in low abundance. In contrast, zircon from the older arc (Eocene to mid-Oligocene, ~ 30–28 Ma) has two different REE patterns: 1) slight enrichment in the light (L)REE, small to absent Ce anomalies, and negative Eu anomalies and 2) enriched High (H)REE, positive Ce anomalies and negative Eu anomalies (a similar pattern is observed in the xenocrystic zircon population). The combination of positive Ce and negative Eu anomalies in the zircon population of the older arc indicates crystallization from magmas that were variably, but considerably less oxidized than those of the younger arc. All the igneous zircon has positive εHf(t), reflecting derivation from a predominantly juvenile mantle source. However, the εHf(t) values vary significantly within samples, reflecting considerable Hf isotopic heterogeneity in the source. The presence of xenocrystic zircon in the southern Lesser Antilles is evidence for the assimilation of intra-arc crustal sediments and/or the recycling and incorporation of sediments into the magma sources in the mantle wedge. Most likely however, primitive magmas stalling and fractionating during their ascent through the Antilles crust entrained ancient zircon. This is evidence by the geochemistry of the study samples, which is inconsistent with any involvement of partially melted subducted sediment. Paleogeographic reconstructions show that the old zircon could derive from distant regions such as the Eastern Andean Cordillera of Colombia, the Merida Andes, and the northern Venezuela coastal ranges, transported for example by the Proto-Maracaibo River precursor of the Orinoco River.",
keywords = "Th disequilibrium, Carriacou-Petite Martinique, Crustal assimilation, Grenada, Lesser Antilles, Zircon xenocryst",
author = "Yamirka ROJAS-AGRAMONTE and WILLIAMS, {Ian S.} and Richard ARCULUS and Alfred KR{\"O}NER and Antonio GARC{\'I}A-CASCO and Concepci{\'o}n L{\'A}ZARO and Stephan BUHRE and Jean WONG and Helen GENG and ECHEVERR{\'I}A, {Carlos Morales} and Teresa JEFFRIES and Hangqian XIE and Regina MERTZ-KRAUS",
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language = "English",
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ROJAS-AGRAMONTE, Y, WILLIAMS, IS, ARCULUS, R, KRÖNER, A, GARCÍA-CASCO, A, LÁZARO, C, BUHRE, S, WONG, J, GENG, H, ECHEVERRÍA, CM, JEFFRIES, T, XIE, H & MERTZ-KRAUS, R 2017, 'Ancient xenocrystic zircon in young volcanic rocks of the southern Lesser Antilles island arc', Lithos, vol. 290-291, pp. 228-252. https://doi.org/10.1016/j.lithos.2017.08.002

Ancient xenocrystic zircon in young volcanic rocks of the southern Lesser Antilles island arc. / ROJAS-AGRAMONTE, Yamirka; WILLIAMS, Ian S.; ARCULUS, Richard; KRÖNER, Alfred; GARCÍA-CASCO, Antonio; LÁZARO, Concepción; BUHRE, Stephan; WONG, Jean; GENG, Helen; ECHEVERRÍA, Carlos Morales; JEFFRIES, Teresa; XIE, Hangqian; MERTZ-KRAUS, Regina.

In: Lithos, Vol. 290-291, 10.2017, p. 228-252.

Research output: Journal PublicationsJournal Article (refereed)

TY - JOUR

T1 - Ancient xenocrystic zircon in young volcanic rocks of the southern Lesser Antilles island arc

AU - ROJAS-AGRAMONTE, Yamirka

AU - WILLIAMS, Ian S.

AU - ARCULUS, Richard

AU - KRÖNER, Alfred

AU - GARCÍA-CASCO, Antonio

AU - LÁZARO, Concepción

AU - BUHRE, Stephan

AU - WONG, Jean

AU - GENG, Helen

AU - ECHEVERRÍA, Carlos Morales

AU - JEFFRIES, Teresa

AU - XIE, Hangqian

AU - MERTZ-KRAUS, Regina

PY - 2017/10

Y1 - 2017/10

N2 - The Lesser Antilles arc is one of the best global examples in which to examine the effects of the involvement of subducted sediment and crustal assimilation in the generation of arc crust. Most of the zircon recovered in our study of igneous and volcaniclastic rocks from Grenada and Carriacou (part of the Grenadines chain) is younger than 2 Ma. Within some late Paleogene to Neogene (~ 34–0.2 Ma) lavas and volcaniclastic sediments however, there are Paleozoic to Paleoarchean (~ 250–3469 Ma) xenocrysts, and Late Jurassic to Precambrian zircon (~ 158–2667 Ma) are found in beach and river sands. The trace element characteristics of zircon clearly differentiate between different types of magmas generated in the southern Lesser Antilles through time. The zircon population from the younger arc (Miocene, ~ 22–19 Ma, to Present) has minor negative Eu anomalies, well-defined positive Ce anomalies, and a marked enrichment in heavy rare earth elements (HREE), consistent with crystallization from very oxidized magmas in which Eu 2 + was in low abundance. In contrast, zircon from the older arc (Eocene to mid-Oligocene, ~ 30–28 Ma) has two different REE patterns: 1) slight enrichment in the light (L)REE, small to absent Ce anomalies, and negative Eu anomalies and 2) enriched High (H)REE, positive Ce anomalies and negative Eu anomalies (a similar pattern is observed in the xenocrystic zircon population). The combination of positive Ce and negative Eu anomalies in the zircon population of the older arc indicates crystallization from magmas that were variably, but considerably less oxidized than those of the younger arc. All the igneous zircon has positive εHf(t), reflecting derivation from a predominantly juvenile mantle source. However, the εHf(t) values vary significantly within samples, reflecting considerable Hf isotopic heterogeneity in the source. The presence of xenocrystic zircon in the southern Lesser Antilles is evidence for the assimilation of intra-arc crustal sediments and/or the recycling and incorporation of sediments into the magma sources in the mantle wedge. Most likely however, primitive magmas stalling and fractionating during their ascent through the Antilles crust entrained ancient zircon. This is evidence by the geochemistry of the study samples, which is inconsistent with any involvement of partially melted subducted sediment. Paleogeographic reconstructions show that the old zircon could derive from distant regions such as the Eastern Andean Cordillera of Colombia, the Merida Andes, and the northern Venezuela coastal ranges, transported for example by the Proto-Maracaibo River precursor of the Orinoco River.

AB - The Lesser Antilles arc is one of the best global examples in which to examine the effects of the involvement of subducted sediment and crustal assimilation in the generation of arc crust. Most of the zircon recovered in our study of igneous and volcaniclastic rocks from Grenada and Carriacou (part of the Grenadines chain) is younger than 2 Ma. Within some late Paleogene to Neogene (~ 34–0.2 Ma) lavas and volcaniclastic sediments however, there are Paleozoic to Paleoarchean (~ 250–3469 Ma) xenocrysts, and Late Jurassic to Precambrian zircon (~ 158–2667 Ma) are found in beach and river sands. The trace element characteristics of zircon clearly differentiate between different types of magmas generated in the southern Lesser Antilles through time. The zircon population from the younger arc (Miocene, ~ 22–19 Ma, to Present) has minor negative Eu anomalies, well-defined positive Ce anomalies, and a marked enrichment in heavy rare earth elements (HREE), consistent with crystallization from very oxidized magmas in which Eu 2 + was in low abundance. In contrast, zircon from the older arc (Eocene to mid-Oligocene, ~ 30–28 Ma) has two different REE patterns: 1) slight enrichment in the light (L)REE, small to absent Ce anomalies, and negative Eu anomalies and 2) enriched High (H)REE, positive Ce anomalies and negative Eu anomalies (a similar pattern is observed in the xenocrystic zircon population). The combination of positive Ce and negative Eu anomalies in the zircon population of the older arc indicates crystallization from magmas that were variably, but considerably less oxidized than those of the younger arc. All the igneous zircon has positive εHf(t), reflecting derivation from a predominantly juvenile mantle source. However, the εHf(t) values vary significantly within samples, reflecting considerable Hf isotopic heterogeneity in the source. The presence of xenocrystic zircon in the southern Lesser Antilles is evidence for the assimilation of intra-arc crustal sediments and/or the recycling and incorporation of sediments into the magma sources in the mantle wedge. Most likely however, primitive magmas stalling and fractionating during their ascent through the Antilles crust entrained ancient zircon. This is evidence by the geochemistry of the study samples, which is inconsistent with any involvement of partially melted subducted sediment. Paleogeographic reconstructions show that the old zircon could derive from distant regions such as the Eastern Andean Cordillera of Colombia, the Merida Andes, and the northern Venezuela coastal ranges, transported for example by the Proto-Maracaibo River precursor of the Orinoco River.

KW - Th disequilibrium

KW - Carriacou-Petite Martinique

KW - Crustal assimilation

KW - Grenada

KW - Lesser Antilles

KW - Zircon xenocryst

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U2 - 10.1016/j.lithos.2017.08.002

DO - 10.1016/j.lithos.2017.08.002

M3 - Journal Article (refereed)

AN - SCOPUS:85034040548

VL - 290-291

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JO - Lithos

JF - Lithos

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ROJAS-AGRAMONTE Y, WILLIAMS IS, ARCULUS R, KRÖNER A, GARCÍA-CASCO A, LÁZARO C et al. Ancient xenocrystic zircon in young volcanic rocks of the southern Lesser Antilles island arc. Lithos. 2017 Oct;290-291:228-252. https://doi.org/10.1016/j.lithos.2017.08.002