Platinum-Group-Element Systematics of Peridotites from Ophiolite Complexes of Northwest Anatolia, Turkey: Implications for Mantle Metasomatism by Melt Percolation in a Supra-subduction Zone Environment

Aldanmaz, Ercan; Köprübaşı, Nezihi

doi:10.2747/0020-6814.48.5.420

Cited by 24 publications

(7 citation statements)

References 64 publications

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“…Oceanic serpentinites also inherit the REE compositions of their mantle protoliths. Figure 4 reports the trace-element compositions of numerous abyssal serpentinites from the large datasets by Deschamps et al (2013) and Peters et al (2017) normalized to the Primitive Mantle (PM, McDonough & Sun, 1995) (the dataset, in Table S1, includes analyses by Lagabrielle et al, 1992;Parkinson & Pearce, 1998;Viti & Mellini, 1998;Anselmi et al, 2000;Pearce et al, 2000;Guillot et al, 2001;Scambelluri et al, 2001b;Chalot-Prat et al, 2003;Garrido et al, 2005;Savov et al, 2005aSavov et al, , b, 2007Aldanmaz & Koprubasi, 2006;Marchesi et al, 2006Marchesi et al, , 2009Paulick et al, 2006;Hattori & Guillot, 2007;Delacour et al, 2008;Pereira et al, 2008;De Hoog et al, 2009;Deschamps et al, 2010Deschamps et al, , 2012Jöns et al, 2010;Saumur et al, 2010;Ulrich et al, 2010;Aziz et al, 2011;Blanco-Quintero et al, 2011;Augustin et al, 2012;Kodolányi et al, 2012;Boschi et al, 2013;Lafay et al, 2013;Andreani et al, 2014;Cannaò et al, 2015Cannaò et al, , 2016…”

Section: Oceanic Serpentinitementioning

confidence: 99%

The water and fluid-mobile element cycles during serpentinite subduction. A review

Scambelluri

Cannaò

Gilio

2019

ejm

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The key role of serpentinites in the global cycles of volatiles, halogens and fluid-mobile elements in oceans and in subduction zones is now ascertained by many studies quantifying their element budgets and the composition of fluids they release during subduction. Geochemical tracers (e.g. B, As, Sb; stable B and radiogenic Sr and Pb isotopes) have also been employed to trace the provenance of serpentinites (slab or forearc mantle?) accreted to the plate interface of fossil subduction zones. In turn, this helps defining the tectonic processes, seismicity and mass transfer attending rock burial and exhumation within subduction zones. The results suggest that the sole use of geochemical data is insufficient to track the origin of subduction-zone serpentinites and the timing of serpentinization, whether oceanic or subduction-related. Integrated multidisciplinary studies of ophiolitic serpentinites show that pristine, oceanic, geochemical imprints (e.g. high 11 B, marine Sr isotopes, low As + Sb) become reset towards more radiogenic Sr, lower 11 B, and higher As + Sb via metasomatic exchange with crust-derived fluids during subduction accretion to the plate interface.The dehydration fluids released by serpentinite dehydration at various subduction stages and still preserved in these rocks as inclusions, carry significant amounts of halogens and fluid-mobile elements. The key compositional similarities of antigorite-breakdown fluids from different localities (Betic Cordillera, Spain; Central Alps, Switzerland) indicate that rocks record comparable subduction processes. We individuate the fluid-mediated exchange with sedimentary and/or crustal reservoirs during subduction as the key mechanism for geochemical hybridization of serpentinite. The antigorite dehydration fluids produced by hybrid serpentinites have high Cs, Rb, Ba, B, Pb, As, Sb and Li overlapping those of the arc lavas and representing the mixed serpentinite-sediment (crustal) component released to arcs. This helps discriminating the mass transfer processes responsible for supra-subduction mantle metasomatism and arc magmatism. The studied plate-interface hybrid serpentinites are also proxies of forearc mantle metasomatized by slab fluids. Based on the above observations, we propose that the mass transfer from slabs to plate interface and/or forearc mantle and the subsequent down-drag of this altered mantle to subarc depths potentially is a major process operating in subduction zones.The nominally anhydrous olivine, orhopyroxene, clinopyroxene and garnet produced by serpentinite dehydration host appreciable amounts of halogens and fluid-mobile elements that can be recycled in the deep mantle beyond arcs. Involvement of de-serpentinized residues in lower mantle metasomatism begins to be increasingly recognized by studies of ocean island basalts (OIB) and of B-bearing blue diamonds and by the isotopic serpentinite compositions presented here.

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Section: Oceanic Serpentinitementioning

confidence: 99%

The water and fluid-mobile element cycles during serpentinite subduction. A review

Scambelluri

Cannaò

Gilio

2019

ejm

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“…Sulphide melt-silicate melt partition coefficients of the PGE are extremely high (Stone et al, 1990;Peach et al, 1994;Fleet et al, 1993Fleet et al, , 1996Naldrett, 1997;Crocket, 2002;Brenan et al, 2005). Ir, Os and Ru with their greater bulk partition co-efficient and higher melting points than Pt and Pd, are most compatible during mantle melting and tend to be concentrated in the mantle residue, while the PPGEs are relatively incompatible among which Pd maintains maximum incompatibility (Barnes et al, 1985;Brenan et al, 2005;Righter et al, 2004;Aldanmaz and Koprubasi, 2010). During partial melting of source mantle and subsequent PGE fractionation, PPGE preferentially enter the extracted melt portion, while the residual mantle gets enriched in IPGE.…”

Section: Melting Conditions Magma Generation and Source Characteristicsmentioning

confidence: 99%

“…Recent studies further suggest that PGEs which are least soluble in silicate melts (e.g. Os, Ir, Ru, Pt) may precipitate as discrete refractory alloys (Bockrath et al, 2004;Aldanmaz and Koprubasi, 2010). As a result, compared to the other PPGEs, Pt is not effectively mobilized during melting and melt migration, lowering Pt/Pd ratios of the melt.…”

Section: Gadwal Boninitesmentioning

confidence: 99%

Platinum Group Elements (PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: Implications for mantle melting processes

Saha

Manikyamba

Santosh

et al. 2015

Journal of Asian Earth Sciences

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“…S1b,c). Furthermore, these rocks are similar to some subducted serpentinites in Mesozoic ophiolites such as those of the Zagros suture zone in Iraq 38 and ophiolite complexes of Northwest Anatolia in Turkey 39 . Previous work (e.g.…”

Section: Discussionmentioning

confidence: 70%

Origin of arc magmatic signature: A temperature-dependent process for trace element (re)-mobilization in subduction zones

Dien

Kil

et al. 2019

Sci Rep

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Serpentinite is a major carrier of fluid-mobile elements in subduction zones, which influences the geochemical signature of arc magmatism (e.g. high abundances of Li, Ba, Sr, B, As, Mo and Pb). Based on results from Neoproterozoic serpentinites in the Arabian-Nubian Shield, we herein report the role of antigorite in the transportation of fluid-mobile elements (FME) and light rare earth elements (LREE) from the subducted slab to arc-related magma during subduction. The serpentinites contain two generations of antigorites: the older generation is coarse-grained, formed at a temperature range of 165–250 °C and is enriched in Li, Rb, Ba and Cs, whereas the younger generation is finer-grained, formed at higher temperature conditions (425–475 °C) and has high concentrations of B, As, Sb, Mo, Pb, Sr and LREE. Magnesite, on the other hand, remains stable at sub-arc depths beyond the stability field of both antigorites, and represents a potential reservoir of FME and LREE for deeper mantle melts. Magnesite has high FME and LREE absorbing capacity (over 50–60%) higher than serpentine phases. Temperature is the main controlling factor for stability of these minerals and therefore the release of these elements from subducted slabs into arc magmatism. As the liberation of these elements varies along the length of the slab, the resulting cross-arc geochemical variation trend can help to determine the subduction polarity of ancient arcs.

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Platinum-Group-Element Systematics of Peridotites from Ophiolite Complexes of Northwest Anatolia, Turkey: Implications for Mantle Metasomatism by Melt Percolation in a Supra-subduction Zone Environment

Cited by 24 publications

References 64 publications

The water and fluid-mobile element cycles during serpentinite subduction. A review

The water and fluid-mobile element cycles during serpentinite subduction. A review

Platinum Group Elements (PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: Implications for mantle melting processes

Origin of arc magmatic signature: A temperature-dependent process for trace element (re)-mobilization in subduction zones

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