Peridotite ≈ Peridotite
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Melting of Peridotites through to Granites: A Simple Thermodynamic Model in the System KNCFMASHTOCr Open
A new set of thermodynamic models is presented for calculating phase relations in bulk compositions extending from peridotite to granite, from 0·001 to 70 kbar and from 650°C to peridotite liquidus temperatures, in the system K2O–Na2O–CaO–…
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The role of pyroxenite in basalt genesis: Melt‐PX, a melting parameterization for mantle pyroxenites between 0.9 and 5 GPa Open
Geochemical and isotopic data suggest that the source regions of oceanic basalts may contain pyroxenite in addition to peridotite. In order to incorporate the wide range of compositions and melting behaviors of pyroxenites into mantle melt…
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Mantle Recycling: Transition Zone Metamorphism of Tibetan Ophiolitic Peridotites and its Tectonic Implications Open
Large peridotite massifs are scattered along the 1500 km length of the Yarlung–Zangbo Suture Zone (southern Tibet, China), the major suture between Asia and Greater India. Diamonds occur in the peridotites and chromitites of several massif…
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The Role of Volatiles in Reactive Melt Transport in the Asthenosphere Open
Experimental studies of mantle petrology find that small concentrations of water and carbon dioxide have a large effect on the solidus temperature and distribution of melting in the upper mantle. However, it has remained unclear what effec…
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Rates and styles of planetary cooling on Earth, Moon, Mars, and Vesta, using new models for oxygen fugacity, ferric-ferrous ratios, olivine-liquid Fe-Mg exchange, and mantle potential temperature Open
Mantle potential temperatures (Tp) provide insights into mantle circulation and tests of whether Earth is the only planet to exhibit thermally bi-modal volcanism—a distinctive signature of modern plate tectonics. Planets that have a stagna…
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New Olivine Reference Material for <i>In Situ</i> Microanalysis Open
A new olivine reference material – Mong OL Sh11‐2 – for in situ analysis has been prepared from the central portion of a large (20 × 20 × 10 cm) mantle peridotite xenolith from a ~ 0.5 My old basaltic breccia at Shavaryn‐Tsaram, Tariat reg…
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Discriminating between pyroxenite and peridotite sources for continental flood basalts (CFB) in southern Africa using olivine chemistry Open
Continental Flood Basalts (CFB) result from voluminous outpourings of magma that often precede continental break-up. Notwithstanding the petrogenetic importance of CFBs, the nature of the mantle source for such magmas is contentious, parti…
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A Revised Adiabatic Temperature Profile for the Mantle Open
This study reevaluates the adiabatic temperature profile of the Earth's mantle. The global average temperature at the 410‐km discontinuity is estimated to be 1839 (38) K by comparing the globally averaged depths of the 410‐km discontinuity…
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Post-collisional Potassic–Ultrapotassic Magmatism of the Variscan Orogen: Implications for Mantle Metasomatism during Continental Subduction Open
Mantle-derived potassic to ultrapotassic magmatism is a typical feature of collisional orogens. Potassium-rich magmas recurrently formed across the European Variscides during a period of 50 Myr, following the peak of the orogeny at 340 Ma.…
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Dehydration-induced rheological heterogeneity and the deep tremor source in warm subduction zones Open
We present observations from an exhumed subduction complex that resembles the environment of modern deep episodic tremor and slow slip (ETS). We focus on the Cycladic Blueschist Unit on Syros Island in Greece. Syros metabasites consist of …
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Experimental evidence of reaction‐induced fracturing during olivine carbonation Open
Mineral carbonation, a process that binds CO 2 in the form of carbonates by silicate weathering, is widespread on the Earth's surface. Because of the abundance of silicate rocks and the permanence of the carbonated solids, sequestering CO …
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Nickel–cobalt contents of olivine record origins of mantle peridotite and related rocks Open
Olivine is distinguished from all other minerals in providing a remarkable chemical narrative about magmatic processes that occurred in Earth's crust, mantle, and core over the entire age of Earth history. Olivines in mantle peridotite hav…
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On the chemical markers of pyroxenite contributions in continental basalts in Eastern China: Implications for source lithology and the origin of basalts Open
Although it is widely recognized that mantle peridotite is compositionally heterogeneous, primitive mantle-like peridotite is commonly considered the potential peridotite source when identifying the source lithology of oceanic and continen…
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Slab dehydration in warm subduction zones at depths of episodic slip and tremor Open
Non-volcanic tremor (NVT) and episodic slow slip events (SSEs) have been observed below the seismogenic zone of relatively warm subduction zones for the past 20 years. Geophysical and geologic observations show that this portion of the sub…
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Cr-spinel records metasomatism not petrogenesis of mantle rocks Open
Mantle melts provide a window on processes related to global plate tectonics. The composition of chromian spinel (Cr-spinel) from mafic-ultramafic rocks has been widely used for tracing the geotectonic environments, the degree of mantle me…
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A Subsolidus Olivine Water Solubility Equation for the Earth's Upper Mantle Open
The pressure and temperature sensitivity of the two most important point hydrous defects in mantle olivine involving Si vacancies (associated to trace amounts of titanium [TiChu‐PD] or exclusively to Si vacancies [Si]) was investigated at …
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Thermal expansivity, heat capacity and bulk modulus of the mantle Open
SUMMARY We derive exact expressions for the thermal expansivity, heat capacity and bulk modulus for assemblages with arbitrarily large numbers of components and phases, including the influence of phase transformations and chemical exchange…
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Iron and magnesium isotopic constraints on the origin of chemical heterogeneity in podiform chromitite from the Luobusa ophiolite, Tibet Open
We present high‐precision measurements of iron (Fe) and magnesium (Mg) isotopic compositions of olivine, orthopyroxene, and chromite separates from harzburgites, dunites, and chromitites in the mantle section of the Luobusa ophiolite, sout…
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Multidisciplinary Constraints on the Abundance of Diamond and Eclogite in the Cratonic Lithosphere Open
Some seismic models derived from tomographic studies indicate elevated shear‐wave velocities (≥4.7 km/s) around 120–150 km depth in cratonic lithospheric mantle. These velocities are higher than those of cratonic peridotites, even assuming…
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Coexisting Early Cretaceous High-Mg Andesites and Adakitic Rocks in the North China Craton: the Role of Water in Intraplate Magmatism and Cratonic Destruction Open
High-Mg andesites (HMAs) and adakitic rocks are purported to occur exclusively in subduction zones in the modern Earth. In the North China Craton, early Cretaceous HMAs and adakitic dacites were erupted in a continental setting, apparently…
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Episodic magmatism and serpentinized mantle exhumation at an ultraslow-spreading centre Open
Mid-ocean ridges spreading at ultraslow rates of less than 20 mm yr−1 can exhume serpentinized mantle to the seafloor, or they can produce magmatic crust. However, seismic imaging of ultraslow-spreading centres has not been able to resolve…
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Chemical and isotopic analyses of hydrocarbon-bearing fluid inclusions in olivine-rich rocks Open
We examined the mineralogical, chemical and isotopic compositions of secondary fluid inclusions in olivine-rich rocks from two active serpentinization systems: the Von Damm hydrothermal field (Mid-Cayman Rise) and the Zambales ophiolite (P…
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Natural olivine crystal-fabrics in the western Pacific convergence region: A new method to identify fabric type Open
Crystallographic preferred orientations (CPOs) of olivine within natural peridotites are commonly depicted by pole figures for the [100], [010], and [001] axes, and they can be categorized into five well-known fabric types: A, B, C, D, and…
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Continental hyperextension, mantle exhumation, and thin oceanic crust at the continent‐ocean transition, West Iberia: New insights from wide‐angle seismic Open
Hyperextension of continental crust at the Deep Galicia rifted margin in the North Atlantic has been accommodated by the rotation of continental fault blocks, which are underlain by the S reflector, an interpreted detachment fault, along w…
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The crust‐mantle interaction in continental subduction channels: Zircon evidence from orogenic peridotite in the Sulu orogen Open
A combined secondary ion mass spectrometer and laser ablation‐(multicollector)‐inductively coupled plasma mass spectrometer study of zircon U‐Pb ages, trace elements, and O and Hf isotopes was carried out for orogenic peridotite and its ho…
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Modeling chemical geodynamics of subduction zones using the Arc Basalt Simulator version 5 Open
Arc Basalt Simulator version 5 (ABS5) is a forward geochemical and petrological model that can be used to examine the element mass balance in primary arc magmas including the source and nature of slab materials and flux melting of the mant…
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Lower plate serpentinite diapirism in the Calabrian Arc subduction complex Open
Mantle-derived serpentinites have been detected at magma-poor rifted margins and above subduction zones, where they are usually produced by fluids released from the slab to the mantle wedge. Here we show evidence of a new class of serpenti…
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The Atlantis Bank Gabbro Massif, Southwest Indian Ridge Open
This paper presents the first detailed geologic map of in situ lower ocean crust; the product of six surveys of Atlantis Bank on the SW Indian Ridge. This combined with major and trace element compositions of primary magmatic phases in 99 …
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Dynamic Accretion Beneath a Slow‐Spreading Ridge Segment: IODP Hole 1473A and the Atlantis Bank Oceanic Core Complex Open
809 deep IODP Hole U1473A at Atlantis Bank, SWIR, is 2.2 km from 1,508‐m Hole 735B and 1.4 from 158‐m Hole 1105A. With mapping, it provides the first 3‐D view of the upper levels of a 660‐km 2 lower crustal batholith. It is laterally and v…
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Primitive Arc Magmatism and Delamination: Petrology and Geochemistry of Pyroxenites from the Cabo Ortegal Complex, Spain Open
The genesis of primitive arc magmas has had a major impact on continent formation through time, but the rarity of exposures of deep arc sections limits our understanding of the details of melt migration and differentiation. Abundant pyroxe…