Zircon trace-element and isotopes (U-Pb, Lu-Hf, δ¹⁸O) response to fluid-deficient metamorphism of a subducted continental terrane (North Muya, Eastern Siberia)

Supplementary Material 5: Zircon data summar

Zircon trace-element and isotopes (U-Pb, Lu-Hf, δ¹⁸O) response to fluid-deficient metamorphism of a subducted continental terrane (North Muya, Eastern Siberia)

Supplementary Material 3: Oxygen isotope

Geochemical behaviours of chemical elements during subduction-zone metamorphism and geodynamic significance

<p>Seafloor subduction and subduction-zone metamorphism (SZM) are understood to be the very cause of both subduction-zone magmatism and mantle compositional heterogeneity. In this article, we compile geochemical data for blueschist and eclogite facies rocks from global palaeo-subduction-zones in the literature, including those from the Chinese Western Tianshan ultrahigh pressure (UHP) metamorphic belt. We synthesize our up-to-date understanding on how chemical elements behave and their controls during subduction-zone metamorphism. Although the compositional heterogeneity of metamorphic minerals from subducted rocks has been recently reported, we emphasize that the mineral compositional heterogeneity is controlled by elemental availability during mineral growth, which is affected by the protolith composition, the inherited composition of precursor minerals, and the competition with neighbouring growing minerals. In addition, given the likely effects of varying protolith compositions and metamorphic conditions on elemental behaviours, we classify meta-mafic rocks from global palaeo-subduction-zones with varying metamorphic conditions into groups in terms of their protolith compositions (i.e. ocean island basalt (OIB)-like, enriched mid-ocean ridge basalt (MORB)-like, normal [N]-MORB-like), and discuss geochemical behaviours of chemical elements within these co-genetic groups rather than simply accepting the conclusions in the literature. We also discuss the geochemical consequences of SZM with implications for chemical geodynamics, and propose with emphasis that: (1) the traditionally accepted ‘fluid flux induced-melting’ model for arc magmatism requires revision; and (2) the residual subducted ocean crust cannot be the major source material for OIB, although it can contribute to the deep mantle compositional heterogeneity. We also highlight some important questions and problems that need further investigations, e.g. complex subduction-zone geochemical processes, different contributions of seafloor subduction and resultant subduction of continental materials, and the representativeness of studied HP–UHP metamorphic rocks.</p

Zircon trace-element and isotopes (U-Pb, Lu-Hf, δ¹⁸O) response to fluid-deficient metamorphism of a subducted continental terrane (North Muya, Eastern Siberia)

Supplementary Material 4: Lu-Hf dat

Zircon trace-element and isotopes (U-Pb, Lu-Hf, δ¹⁸O) response to fluid-deficient metamorphism of a subducted continental terrane (North Muya, Eastern Siberia)

Supplementary Material 2: U-Pb trace dat

Zircon trace-element and isotopes (U-Pb, Lu-Hf, δ¹⁸O) response to fluid-deficient metamorphism of a subducted continental terrane (North Muya, Eastern Siberia)

Supplementary Material 1: EPMA Dat

Geochemistry, mineral chemistry and Re–Os isotopes of refractory peridotites of the North Balkhash ophiolite zone in the West Central Asian Orogenic Belt (Central Kazakhstan): multi-stage melt evolution of a Late Precambrian forearc mantle

Supplementary Figure S

Geochemistry, mineral chemistry and Re–Os isotopes of refractory peridotites of the North Balkhash ophiolite zone in the West Central Asian Orogenic Belt (Central Kazakhstan): multi-stage melt evolution of a Late Precambrian forearc mantle

Supplementary Figure S

Cyclopentadithiophene–Terephthalic Acid Copolymers: Synthesis via Direct Arylation and Saponification and Applications in Si-Based Lithium-Ion Batteries

This study investigates conjugated polymers comprising of cyclopentadithiophene and dimethyl terephthalate or terephthalic acid units for use in Si-based lithium-ion batteries. Cyclopentadithiophene tethered with 2-ethylhexyl or triethylene glycol side chains and 2,5-dibromo­terephthalate are copolymerized via palladium-complex-catalyzed direct arylation. The dimethyl ester groups in the dimethyl terephthalate unit are converted to the carboxyl groups via saponification. The polymers are mixed with Si nanoparticles to fabricate an anode electrode for use in lithium-ion batteries. Compared with polymers before saponification, the batteries with the electrodes incorporating the saponified polymers have greater specific capacities of up to 2500 mA h g^–1 (for total anode weight) at a second cycle and greater stability. Electrolyte uptake test and scanning electron microscopy are used to verify the battery performance