Melt extraction and melt refertilization in mantle peridotite of the Coast Range ophiolite: an LA–ICP–MS study

Jean, M. M.; Shervais, John W.; Choi, Sung Hi; Mukasa, Samuel B.

doi:10.1007/s00410-009-0419-0

Cited by 72 publications

(56 citation statements)

References 70 publications

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“…Brunelli et al 2006;Le Roux et al 2007;Jean et al 2010) was not found in the studied Cpx harzburgite. Most of the Cpx 1 should have undergone the batch partial melting during the E2 event and, on this basis, we speculate that the Cpx 1 contents of our residual harzburgites were originally higher.…”

Section: The E2 Partial Melting Mantle Eventmentioning

confidence: 76%

The blueschist-associated perovskite-andradite-bearing serpentinized harzburgite from Dobšiná (the Meliata Unit), Slovakia

Putiš¹,

Koppa²,

Snarska³

et al. 2013

J. Geosci.

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Unique, perovskite(Prv)-andradite(Adr)-bearing serpentinized harzburgite fragments occur in Late Jurassic-Early Cretaceous subduction-accretionary wedge complex of the Meliata tectonic Unit (Slovakia, Western Carpathians). These rocks reflect magmatic (E1) and partial melting (E2) mantle events followed by metamorphic blueschist-facies (E3) and fluid-rock interaction (E4) events accompanied by crystallization of Prv and/or Adr. The incompletely solidified slightly depleted (residual) harzburgite composed of early-magmatic assemblage of Ol, Opx 1 , Cr-Spl ± Cpx 1 (E1 event) underwent partial melting (E2 event) under subsolidus mantle conditions. The late-magmatic aggregates of Cpx 2 , Cr-Spl, scarce Opx 2 , due to this batch melting, occur around the Opx 1 (±Cpx 1 ) porphyroclasts. The fractures and cleavage planes of the kinked Opx 1 porphyroclasts are filled by Cpx 3 as a result of subsolidus recrystallization of the Opx 1 . Cloudy lower Al Cpx 4 associated with pargasite in reaction rims between the Opx 1 and Cpx 2 , or antigorite replacing Ol, could represent the E3 high-pressure metamorphic event (dated at 160 to 150 Ma, according to published 40 Ar- 39Ar data for "phengitic" white mica from blueschists) in serpentinites. Serpentinized zones of harzburgite contain Prv, which occurs in serpentinized Opx 1 porphyroclasts. Orthopyroxene (Opx 1 ) breakdown and formation of Prv, (Ti-rich) Adr and chrysotile appears to be postdating the closure of the Meliata back-arc basin (c. 200 to 160 Ma) and HP metamorphism. Perovskite genesis can therefore be bound to the exhumation-related serpentinization in subduction channel and emplacement of serpentinites into subduction-accretionary wedge (E4 event at 300-500 ºC/5-15 kbar, at 150 to 130 Ma?). The bulk-rock trace-element patterns suggest enrichment in LREE, Ba, Cs, U, Pb, Sb and Li in comparison with HREE, HFSE, Rb and Sr. Such element mobility indicates fluid-rock interaction. Pervading aqueous fluids rich in CO 2 were transporting Ca, Ti, Fe, LREE partitioned into Prv grown along the Cpx exsolution lamellae in Opx 1 . The sources of such fluids might have been the blueschist-to greenschist-facies rocks from the Meliata mélange type subduction-accretionary wedge. The late-metamorphic H 2 O-CO 2 /Si-Fe-Mn-rich fluids caused partial replacement of Prv by pyrophanite and crystallization of (Ti-rich) Adr at the expense of Cpx and Prv. : harzburgite, blueschist, perovskite, andradite, fluid-rock interaction, Meliata Back-arc Basin Received: 22 July 2012; accepted: 23 December 2012; handling editor: E. Jelínek The online version of this article (http://dx.doi.org/10.3190/jgeosci.128) contains supplementary electronic material. Keywords

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Section: The E2 Partial Melting Mantle Eventmentioning

confidence: 76%

The blueschist-associated perovskite-andradite-bearing serpentinized harzburgite from Dobšiná (the Meliata Unit), Slovakia

Putiš¹,

Koppa²,

Snarska³

et al. 2013

J. Geosci.

View full text Add to dashboard Cite

show abstract

“…Detailed petrologic, isotopic, and geochemical studies of these peridotites have documented conclusively that they either formed in a supra-subduction zone setting (Groups B and C) or represent abyssal-like peridotites (Group A) that were modified by subduction zone processes (Choi et al, 2008a,b;Jean et al, 2010;Shervais et al, 2011). Thus, we may use these samples as analogs for the mantle wedge above a subduction zone, in order to document how FME become enriched in the source region of arc volcanics.…”

Section: Regional Settingmentioning

confidence: 97%

“…Coast Range ophiolite crustal rocks are underlain in most locales by serpentinized or partially serpentinized peridotites (Shervais et al, 2004;Choi et al, 2008a,b;Jean et al, 2010). In the northern Coast Ranges the serpentinized peridotites are commonly associated with a serpentinite matrix melange, comprising blocks of massive peridotite and exotic blocks of igneous and metamorphic rocks in a matrix of sheared serpentinite (Hopson and Pessagno, 2005;Shervais et al, 2011).…”

Section: Regional Settingmentioning

confidence: 97%

“…This mantle reflects the processes that have affected it through time, including melt extraction, fluid phase enrichment, and melt refertilization, which have been frozen in place by cooling and emplacement. A primary advantage of this approach is the fact that large tracts of mantle wedge peridotite are commonly exposed at the base of many supra-subduction ophiolites, allowing us to examine, in situ, their petrology, geochemistry, and structure on longer length scales than is currently possible in any active system (Batanova et al, 1998;Batanova and Sobolev, 2000;Bizimis et al, 2000;Nicolas and Boudier, 2000;LeMee et al, 2004;Choi et al, 2008a,b;Barth et al, 2008;Jean et al, 2010).…”

Section: Introductionmentioning

confidence: 97%

“…Jean et al (2010) presented trace element systematics of the rare earth, high-field strength, and transition elements to model the amount of hydrous partial melting that occurred within the mantle wedge. In this study we extend the work of Jean et al (2010) to the FME using newly acquired in situ laser ablation ICP-MS analyses of clinopyroxene. Our approach models the active processes that occur within the dynamic mantle wedge, and the total addition of material to the mantle wedge source region.…”

Section: Introductionmentioning

confidence: 99%

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