Subduction of fracture zones controls mantle melting and geochemical signature above slabs

Manea, Vlad Constantin; Leeman, William P.; Gerya, Taras; Manea, Marina; Zhu, Guizhi

doi:10.1038/ncomms6095

Cited by 48 publications

(48 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Relative to other incompatible elements, B tends to be selectively enriched in most arc lavas-with maximum enrichments (at any given subduction zone) observed in frontal rather than back-arc regions [Leeman et al, 1994[Leeman et al, , 2004Ishikawa and Nakamura, 1994;Ryan et al, 1995;Tonarini et al, 2001]. Also, anomalous enrichment of B is commonly associated with unusual tectonic settings, such as areas where fracture zones are subducted [Singer et al, 2007;Manea et al, 2014]. Moreover, positive correlations between B enrichment (e.g., B/Be) and 10 Be/ 9 Be in arc lavas provide ''smoking gun'' evidence that the B signal is in some manner slab-derived [Morris et al, 1990;Ryan et al, 1995;Ishikawa et al, 2001].…”

Section: Citationmentioning

confidence: 99%

Boron isotope variations in Tonga‐Kermadec‐New Zealand arc lavas: Implications for the origin of subduction components and mantle influences

Leeman

Tonarini

Turner

2017

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

The Tonga‐Kermadec‐New Zealand volcanic arc is an end‐member of arc systems with fast subduction suggesting that the Tonga sector should have the coolest modern slab thermal structure on Earth. New data for boron concentration and isotopic composition are used to evaluate the contrasting roles of postulated subduction components (sediments and oceanic slab lithologies) in magma genesis. Major observations include: (a) Tonga‐Kermadec volcanic front lavas are enriched in B (as recorded by B/Nb and similar ratios) and most have relatively high δ11B (>+4‰), whereas basaltic lavas from New Zealand have relatively low B/Nb and δ11B (<−3.5‰); (b) both δ11B and B/Nb generally increase northward from New Zealand along with convergence rate and overall slab flux; (c) δ11B and B/Nb decrease toward the back‐arc, as observed elsewhere; and (d) low δ11B is observed in volcanic front samples from Ata, an anomalous sector where the back‐arc Valu Fa Spreading Center impinges on the arc and the Louisville Seamount Chain is presently subducting. Otherwise, volcanic front lavas exhibit positive correlations for both B/Nb and δ11B with other plausible indicators of slab‐derived fluid contributions (e.g., Ba/Nb, U/Th, (230Th/232Th) and 10Be/9Be), and with estimated degree of melting to produce the mafic lavas. Inferred B‐enrichments in the arc magma sources are likely dominated by serpentinite domains deeper within the subducting slab (±altered oceanic crust), and B systematics are consistent with dominant transport by slab‐derived aqueous fluids. Effects of this process are amplified by mantle wedge source depletion due to prior melt extraction.

show abstract

Section: Citationmentioning

confidence: 99%

Boron isotope variations in Tonga‐Kermadec‐New Zealand arc lavas: Implications for the origin of subduction components and mantle influences

Leeman

Tonarini

Turner

2017

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

show abstract

“…3). This is probably the result of extensive dehydration of the slab before it reaches sub-arc depths (Leeman et al, 2004;Manea et al, 2014).…”

Section: The Source Of Volatiles In Lassen Region Primitive Magmasmentioning

confidence: 99%

Slab melting and magma formation beneath the southern Cascade arc

Walowski

Wallace

Clynne

et al. 2016

Earth and Planetary Science Letters

View full text Add to dashboard Cite

The processes that drive magma formation beneath the Cascade arc and other warm-slab subduction zones have been debated because young oceanic crust is predicted to largely dehydrate beneath the forearc during subduction. In addition, geochemical variability along strike in the Cascades has led to contrasting interpretations about the role of volatiles in magma generation. Here, we focus on the Lassen segment of the Cascade arc, where previous work has demonstrated across-arc geochemical variations related to subduction enrichment, and H-isotope

show abstract

“…In the last years a variety of models studied subduction zones in 3D using either physical (e.g., Boutelier et al, 2014;Dominguez et al, 2000;Duarte et al 2013;Funiciello et al, 2008;Malavieille and Trullenque, 2009), semianalytical (Royden and Husson, 2006) or numerical methods (e.g., Capitanio et al, 2007;Jadamec and Billen, 2010;Malatesta et al, 2013;Manea et al, 2014;Schellart et al, 2007;Stegman et al, 2010;Sternai et al, 2014;Yamato et al, 2009;Hampel, 2015, 2016); these works tested several subduction-related topics as e.g. the deformation mechanisms and the influencing parameters of accretionary wedges, the role of margins geometry, interplate rheology and mantle processes on upper plate deformation and on subduction kinematics and dynamics.…”

Section: Introductionmentioning

confidence: 99%

Interplate deformation at early‐stage oblique subduction: 3‐D thermomechanical numerical modeling

et al. 2016

Self Cite

View full text Add to dashboard Cite

Oblique subduction zones are complex settings where the simultaneous action of trench‐normal and trench‐parallel components of convergence can produce heterogeneous deformational pattern of the upper plate and affect the accretional/erosional behavior of the plate margin. Here we present three‐dimensional thermomechanical numerical models that highlight some processes occurring in the early history (15–20 Myr) of intraoceanic oblique subduction zones, which so far represent the less studied case. These models have been compared with a simulation of a slab sinking under a continental plate. We test subduction starting in oceans floored by two classes of lithosphere: layered (fast spreading oceans) and serpentinite rich (slow to ultraslow spreading oceans). Two main domains develop along the margin of both type of oceanic plates: (a) a domain with a mostly stable trench, a shortening upper plate, characterized by the formation of a topographic relief, and (b) a domain with retreating trench and extending upper plate. In general, we observed that varying the subduction obliquity, the margin could either (i) record an erosional to a balanced accretion/erosion regime or (ii) be characterized by a predominant balanced accretion/erosion regime. In both cases, even where the sediment amount in the trench is high, the upper plate experiences tectonic erosion. We suggest that the formation of topographic reliefs on the fore arc is possibly related to the low amount of sediment in the trench, affecting interplate friction and promoting the upper plate indentation against the slab. The Puysegur subduction zone and the central Andes can be possibly natural examples of such a regime.

show abstract

Subduction of fracture zones controls mantle melting and geochemical signature above slabs

Cited by 48 publications

References 66 publications

Boron isotope variations in Tonga‐Kermadec‐New Zealand arc lavas: Implications for the origin of subduction components and mantle influences

Boron isotope variations in Tonga‐Kermadec‐New Zealand arc lavas: Implications for the origin of subduction components and mantle influences

Slab melting and magma formation beneath the southern Cascade arc

Interplate deformation at early‐stage oblique subduction: 3‐D thermomechanical numerical modeling

Contact Info

Product

Resources

About