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Tectonic and crustal processes drive multi-million year arc magma evolution leading up to porphyry copper deposit formation in central Chile J. Petrol. (IF 3.9) Pub Date : 2024-03-12 Simon J E Large, Chetan L Nathwani, Jamie J Wilkinson, Thomas R Knott, Simon R Tapster, Yannick Buret
Subduction zone magmatism is a major control of volcanism, the generation of modern continental crust and the formation of economically important porphyry Cu-(Mo-Au) deposits. Reading the magmatic record of individual arc segments, and constraining the rates of magmatic changes, are critical in order to fully understand and quantify the processes that drive magma evolution in subduction settings during
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The Role of Crustal Contamination Throughout the 1329–2005 CE Eruptive Record of Mt. Etna Volcano, Italy J. Petrol. (IF 3.9) Pub Date : 2024-03-04 Marie K Takach, Wendy A Bohrson, Frank J Spera, Marco Viccaro
The nearly continuous volcanic eruption record at Mt. Etna dating back ~700 years provides an excellent opportunity to investigate the geochemical evolution of a highly active volcano. Of particular interest is elucidating the cause of selective enrichment in alkali elements (K and Rb) and 87Sr/86Sr observed in various episodes of past activity. More recently, this alkali enrichment trend started to
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A machine learning-based thermobarometer for magmatic liquids J. Petrol. (IF 3.9) Pub Date : 2024-03-02 Gregor Weber, Jon Blundy
Experimentally calibrated models to recover pressures and temperatures of magmas, are widely used in igneous petrology. However, large errors, especially in barometry, limit the capacity of these models to resolve the architecture of crustal igneous systems. Here we apply machine learning to a large experimental database to calibrate new regression models that recover P-T of magmas based on melt composition
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Textures and chemistry of crystal cargo of The Pleiades Volcanic Field, Antarctica: potential influence of ice load in modulating the plumbing system J. Petrol. (IF 3.9) Pub Date : 2024-03-01 Rocchi Irene, Tomassini Alice, Masotta Matteo, Petrelli Maurizio, Ágreda López Mónica, Rocchi Sergio
The Pleiades Volcanic Field (PVF) of northern Victoria Land (Antarctica) is made up of a dozen scoria cones whose erupted products present an unusually complete evolutionary trend from alkali-basalt to trachyte. With the aim of reconstructing the evolution of the PVF plumbing system, we have investigated the petrography and chemistry of main mineral phases using SEM-EDS coupled with major (EPMA-WDS)
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Protracted and progressive crustal melting during continental collision in the Pamir and plateau growth J. Petrol. (IF 3.9) Pub Date : 2024-03-01 Gong-Jian Tang, Derek A Wyman, Wei Dan, Qiang Wang, Xi-Jun Liu, Ya-Nan Yang, Mustafo Gadoev, Ilhomjon Oimahmadov
Determining crustal melting in parallel with geodynamic evolution provides critical information on plateau crustal thickening and uplift. Here we investigate the timing and duration of crustal melting through in-situ analysis of zircon U-Pb ages, trace elements and Hf-O isotopes, and whole-rock elements and Sr-Nd-Hf isotopes for the granites and high-grade metamorphic rocks from the Pamir Plateau.
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Apatite chemistry as a petrogenetic indicator for mafic layered intrusions J. Petrol. (IF 3.9) Pub Date : 2024-02-29 Marie A Kieffer, Sarah A S Dare, Olivier Namur, Eduardo T Mansur
Mafic layered intrusions constitute a natural laboratory to investigate petrogenetic processes using trace element variations in apatite chemistry. Although these intrusions are related to large igneous provinces, there is a wide range of parameters that can affect the chemistry of the primary melt (i.e., composition of the source, pressure, temperature, oxygen fugacity), followed by possible crustal
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Genesis of andesitic magma erupted at Yufu Volcano, Kyushu Island, Southwest Japan arc: Evidence from the chemical compositions of amphibole phenocrysts J. Petrol. (IF 3.9) Pub Date : 2024-02-29 Ikuo Okada, Tomoyuki Shibata, Masako Yoshikawa, Hidemi Ishibashi, Takeshi Sugimoto, Yasutaka Hayasaka
The major- and trace-element compositions of amphiboles in andesite from Quaternary Yufu Volcano, northeastern Kyushu, Japan were analysed to investigate the generation processes of andesitic magma from Yufu Volcano. The amphiboles in andesite from Yufu volcano can be divided into two groups based on major-element composition: pargasite and magnesio-hornblende. To estimate temperature, pressure, and
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Postcumulus processes recorded in whole-rock geochemistry: a case study from the Mirabela layered intrusion, Brazil J. Petrol. (IF 3.9) Pub Date : 2024-02-29 Stephen J Barnes, Morgan Williams
According to the “trapped liquid” paradigm, whole-rock chemical compositions of cumulate rocks in layered intrusions can be represented as closed-system multicomponent mixtures of the cumulus phases and the liquids from which they crystallised. Alternative open-system models for cumulate solidification assert that intercumulus liquid is continuously mobile as a result of compaction of crystal mushes
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Metamorphism of dolomitic and magnesitic rocks in collisional orogens and implications for orogenic CO2 degassing J. Petrol. (IF 3.9) Pub Date : 2024-02-29 Tamang Shashi, Groppo Chiara, Girault Frédéric, Perrier Frédéric, Rolfo Franco
Carbonate-bearing sediments, containing calcite, dolomite or magnesite as major carbonate components, are important components of sedimentary sequences deposited on passive margins through Earth’s history. When involved in collisional orogenic processes, these sediments are metamorphosed at variable temperatures and pressures, and undergo decarbonation reactions. While the orogenic metamorphism of
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Fluid-induced metamorphism and deformation at the eastern boundary of the Sveconorwegian Province J. Petrol. (IF 3.9) Pub Date : 2024-02-03 C L Urueña, C Möller
The Sveconorwegian orogen in Scandinavia and the Grenville orogen in Canada are both remnants of large and hot orogens that formed part of the supercontinent Rodinia around 1 billion years ago. Formerly deeply buried portions of crust in these orogens are exposed and offer insights into the tectonic dynamics of the basement within large orogens. The Eastern Segment of the Sveconorwegian Province hosts
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Comment on ‘The Generation of Eocene Mafic Dike Swarms During the Exhumation of a Core Complex, Biarjmand Area, NE Iran’ by Azizi et al. (2023), Journal of Petrology, 64, 1-18 J. Petrol. (IF 3.9) Pub Date : 2024-02-03 Ahmadreza Malekpour-Alamdari
Azizi et al. (2023) have attributed the E-W-oriented mafic dike swarm in the Biarjmand metamorphic core complex to an Eocene extensional event which is much younger than a previously suggested Late Jurassic-Early Cretaceous age (Malekpour-Alamdari et al., 2017). They proposed that the emplacement of these dikes occurred in a rapid extensional regime coeval with the exhumation of the core complex after
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The Primary Geology of the Paleoproterozoic MT Weld Carbonatite Complex, Western Australia J. Petrol. (IF 3.9) Pub Date : 2024-02-03 Ross Chandler, Ganesh Bhat, John Mavrogenes, Brad Knell, Rhiannon David, Thomas Leggo
The paleoregolith overlying the c. 2.06 Ga Mt Weld carbonatite (eastern Yilgarn Craton, Western Australia) hosts one of the largest Rare Earth Element (REE) deposits globally. Historic exploration and research has focussed on this weathered material, with a lack of unweathered samples preventing a thorough investigation into the nature of the underlying carbonatite. Recent deep drilling has allowed
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The role of peritectic biotite for the chemical and mechanical differentiation of felsic plutonic rocks (Western Adamello, Italy) J. Petrol. (IF 3.9) Pub Date : 2024-02-03 Thomas Grocolas, Othmar Müntener
The volcanic–plutonic connection plays a fundamental role for magmatic systems, linking crystallising plutons, volcanic activity, volatile exsolution and ore deposits. Nonetheless, our understanding of the nature of these links is limited by the scarcity of continuous outcrops exhibiting clear relationships between the plutonic roots that feed its volcanic counterpart. One way to better characterise
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Estimates of Crystallinity utilizing Differential Scanning Calorimetry: Application to the Kīlauea 2018 lower East Rift Zone Eruption J. Petrol. (IF 3.9) Pub Date : 2024-02-02 B A Halverson, A Emerson, J Hammer, J Lira, A Whittington
Rocks produced by diverse processes, from condensation in space to impacts on planetary surfaces to volcanism, contain both crystals and amorphous material. Crystallinity provides information on the thermal history of the sample and is especially important in characterizing volcanic rocks and pyroclasts because lava rheology is profoundly influenced by the crystal content. Crystallinity is typically
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Incomplete hydration during ‘retrograde’ metamorphism: ‘Barrovian’ kyanite-, staurolite-, chloritoid-bearing pseudomorphs after andalusite (Cap de Creus, E Pyrenees, Spain) J. Petrol. (IF 3.9) Pub Date : 2024-01-30 Pavel Pitra, Francisco José Martínez
Metapelitic rocks from Cap de Creus (Eastern Pyrenees, Spain) have developed andalusite±cordierite-bearing assemblages during the Variscan low-pressure high-temperature metamorphism. Andalusite crystals are commonly transformed to very fine-grained assemblages containing white micas with various combinations of staurolite, kyanite, chloritoid, and/or biotite, chlorite, corundum. The hydrous character
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Tracking garnet dissolution kinetics in 3D using deep learning grain shape classification J. Petrol. (IF 3.9) Pub Date : 2024-01-30 Philip Hartmeier, Pierre Lanari, Jacob B Forshaw, Thorsten A Markmann
The kinetics of fluid-driven metamorphic reactions are challenging to study in nature because of the tendency of metamorphic systems to converge towards chemical equilibrium. However, in cases where mineral textures that reflect incomplete reactions are preserved, kinetic processes may be investigated. Atoll garnet, a texture formed by the dissolution of a garnet’s core, has been described in 2D from
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The origin and differentiation of CO2-rich primary melts in Ocean Island volcanoes: Integrating 3D X-ray tomography with chemical microanalysis of olivine-hosted melt inclusions from Pico (Azores) J. Petrol. (IF 3.9) Pub Date : 2024-01-30 Thomas D van Gerve, David A Neave, Penny Wieser, Hector Lamadrid, Niels Hulsbosch, Olivier Namur
Constraining the initial differentiation of primary mantle melts is vital for understanding magmatic systems as a whole. Chemical compositions of olivine-hosted melt inclusions preserve unique information about the mantle sources, crystallisation behaviour and volatile budgets of such melts. Crucially, melt inclusion CO2 contents can be linked to mantle CO2 budgets and inform us on Earth’s carbon fluxes
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Are microstructures in plutonic rocks primary or secondary?: a re-examination of the metasomatism hypothesis for the roof-sourced autoliths in the Skaergaard intrusion J. Petrol. (IF 3.9) Pub Date : 2024-01-17 Marian B Holness, Jens C Ø Andersen, Olivier Namur, Troels F D Nielsen
The roof-derived autoliths in the floor cumulates of the Skaergaard Intrusion have been argued to have been extensively metasomatized and recrystallised, forming the foundation of the hypothesis that microstructures in plutonic rocks are essentially metamorphic. However, the augite-plagioclase-plagioclase dihedral angles and plagioclase core composition of the autoliths match with those of the roof
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The elusive Congo craton margin during Gondwana breakup: Insights from lithospheric mantle structure and heat-flow beneath the Xaudum kimberlite province, NW Botswana J. Petrol. (IF 3.9) Pub Date : 2024-01-17 Azhar M Shaikh, Sebastian Tappe, Fanus Viljoen, Mike C J de Wit
The continental lithospheric mantle (CLM) beneath the southern margin of the Congo craton has remained elusive mainly because of thick Phanerozoic sedimentary cover concealing possible kimberlite and lamproite diatremes. In this study, we explore this lithospheric mantle section by using major and trace element compositions of mantle-derived clinopyroxene and garnet xenocrysts from kimberlites of the
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The effects of partial melting and metasomatism on peridotite water contents: insights from Shuangliao Volcano Group, Northeast China J. Petrol. (IF 3.9) Pub Date : 2024-01-17 Chang-Yu Zhu, Huan Chen, Yan-Tao Hao
Many minerals within the subcontinental lithospheric mantle (SCLM) contain structurally bonded hydrogen (commonly referred to as “water”), which significantly impacts their physical properties and associated geodynamic processes. Observations from different localities worldwide make understanding the behavior of hydrogen during partial melting and mantle metasomatism a contentious issue, as different
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An amphibole perspective on the recent magmatic evolution of Mount St. Helens J. Petrol. (IF 3.9) Pub Date : 2024-01-09 Franziska Keller, Maren Wanke, Nico Kueter, Marcel Guillong, Olivier Bachmann
Compositional variations of amphibole stratigraphically recovered from multiple eruptions at a given volcano have a great potential to archive long-term magmatic processes in its crustal plumbing system. Calcic amphibole is a ubiquitous yet chemically and texturally diverse mineral at Mount St. Helens (MSH), where it occurs in dacites and in co-magmatic enclaves throughout the Spirit Lake stage (last
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Oligocene high-MgO alkali basalts in central Tibet: implications for magma–mush mixing and mantle processes J. Petrol. (IF 3.9) Pub Date : 2023-12-15 Yue Qi, Qiang Wang, Gang-Jian Wei, Xiu-Zheng Zhang, Wei Dan, Zong-Yong Yang, Lu-Lu Hao, Wan-Long Hu
High-MgO (> 9 wt.%) basaltic rocks can be primary magmas and used to constrain the geochemistry and temperature of the mantle. However, high MgO contents can also result from mixing between evolved melts and antecrysts or xenocrysts, and thus the whole-rock composition might not represent the solidified equivalents of primary magma. Whether such mixing with crystals can result in erroneous interpretations
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Plutonic nature of a transcrustal magmatic system: evidence from ultrahigh resolution Sr-disequilibria in plagioclase microantecrysts from the southern Taupo Volcanic Zone, New Zealand J. Petrol. (IF 3.9) Pub Date : 2023-12-14 Daniel A Coulthard Jr, Raimundo Brahm, Charline Lormand, Georg F Zellmer, Naoya Sakamoto, Yoshiyuki Iizuka, Hisayoshi Yurimoto
The residence timescales of antecrystic minerals contribute a key piece of information regarding the petrologic evolution of transcrustal magmatic systems and may be inferred using a combination of observations derived from microanalytical chemistry and diffusion modelling. Here, we present state-of-the-art stacked CMOS-type active pixel sensor (SCAPS) isotopographic images of tephra-hosted plagioclase
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Connecting the dots: the lava domes’ perspective of magmatism related to an ignimbrite flare-up J. Petrol. (IF 3.9) Pub Date : 2023-12-14 L Smithies Sarah, M Gravley Darren, A R Gualda Guilherme
Dome eruptions associated with rhyolitic calderas offer an important insight into how extremely large (>>10 km3), rhyolitic magma systems are constructed through time. We focus on rhyolitic calderas in the central Taupō Volcanic Zone leading to, during, and immediately following the 350 – 240 ka ignimbrite flare-up. We identified 103 dome eruptions that are dated between ca. 650 and 150 ka and collated
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Plumbing system architecture and differentiation processes of the Nyiragongo volcano, DR Congo J. Petrol. (IF 3.9) Pub Date : 2023-12-07 Sander M Molendijk, Olivier Namur, Ephrem Kamate Kaleghetso, Paul R D Mason, Benoît Smets, Jacqueline Vander Auwera, David A Neave
The Nyiragongo volcano is one of the most alkali-rich volcanic centres on the planet (Na2O + K2O generally >10 wt.%, agpaitic index up to 1.34), characterized by a semi-permanently active lava lake which hosts silica-undersaturated (SiO2 <40 wt.%), low viscosity lavas. To improve our understanding of this unique magmatic system, we present a set of 291 samples, acquired during new field excursions
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Competing roles of evolving P-T conditions, equilibration volume and chemical potential landscape in the formation of corona texture: a case study from the Southern Granulite Terrane, India J. Petrol. (IF 3.9) Pub Date : 2023-11-20 Anindita Dey, Sirina Roy Choudhury, Pulak Sengupta
Corona texture is defined by the development of partial or complete rim of one or more minerals around a central reactant mineral depicting limited mass transport (local equilibration) in the length scale of the coronitic layers. The mineral assemblages forming corona texture in a metamorphic rock are commonly used to trace the P-T-X conditions through which the rock evolved during various tectonic
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Testing the limits of Ti-in-Quartz thermometry and diffusion modelling to determine the thermal history of the Fish Canyon Tuff J. Petrol. (IF 3.9) Pub Date : 2023-11-13 Karoline Brückel, Craig Campbell Lundstrom, Michael Ackerson, Christopher Campe
How silicic magmas are stored in the upper crust before they erupt to form 100-1000s km3 ash-sheets remains a fundamental, but unanswered question in volcanology. While some studies posit storage in an eruptible state at low viscosity (<50% crystals) and high temperatures (>760-740°C) (warm storage), others suggest storage in a rigid state (>50% crystals) at lower, near-solidus temperatures (cold storage)
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Oceanic and continental lithospheric mantle in the 1.95 Ga Jormua Ophiolite Complex, Finland: implications for mantle and crustal evolution J. Petrol. (IF 3.9) Pub Date : 2023-11-06 Valerie A Finlayson, Mitchell Haller, James M D Day, Stephen Ginley, Brian O’Driscoll, Asko Kontinen, Eero Hanski, Richard J Walker
The ca. 1.95 Ga Jormua Ophiolite Complex (JOC), Finland, is a rare Paleoproterozoic ophiolite that preserves a record of diverse upper mantle materials and melting processes. Meter-scale grid sampling of four JOC outcrops, as well as non-grid samples, permits evaluation of meter- to kilometer-scale mantle heterogeneity within the JOC. Significant heterogeneity is observed between the four grids, and
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Zircon Microstructures in Large, Deeply Eroded Impact Structures and Terrestrial Seismites J. Petrol. (IF 3.9) Pub Date : 2023-10-23 Adam Andreas Garde, Leif Johansson, Nynke Keulen, Anja Schreiber, Richard Wirth
Extraterrestrial cratering was a critical component in the evolution of the early Earth, but discovery of very ancient and deeply exhumed impact structures remains elusive, as identification tools are in short supply. The recognition of such structures is hindered by post-cratering geological processes, whereby impact-induced features common in younger, upper-crustal craters may be lost. In this study
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New experimental constraints for the evolution and thermobarometry of alkali ultrabasic to intermediate igneous rocks J. Petrol. (IF 3.9) Pub Date : 2023-10-18 Andrés Fabián Salazar-Naranjo, Silvio Roberto Farias Vlach
We report new experimental data from ultrabasic basanite and ultrabasic tephrite as starting material compositions in the 1350 - 1000°C temperature range. Crystallization experiments under low- to high-pressure (0.5 to 2.0 GPa) were carried out under reduced conditions (≈CCO buffer), while one-atmosphere, anhydrous, experiments were performed ranging from reduced to oxidized conditions (-2 ≤ QFM ≤
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An extended calibration of the olivine–spinel aluminum exchange thermometer: Application to the melting conditions and mantle lithologies of large igneous provinces J. Petrol. (IF 3.9) Pub Date : 2023-10-11 Yishen Zhang, Olivier Namur, Weiran Li, Oliver Shorttle, Esteban Gazel, Eleanor Jennings, Peter Thy, Timothy L Grove, Bernard Charlier
The application of the olivine–spinel aluminum exchange thermometer to natural samples is limited by the restricted experimental dataset on which it was calibrated. Here, we present a new dataset of 46 high-temperature crystallization experiments and 21 reanalyzed published experiments, which we used to extend the calibration to higher and lower temperatures. The final calibration dataset spans a range
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Sheared Peridotites from northern Lesotho: Metasomatism-induced Deformation and Craton Destabilization J. Petrol. (IF 3.9) Pub Date : 2023-10-11 Catharina Heckel, Alan B Woodland, Jolien Linckens, Sally A Gibson, Hans-Michael Seitz
Sheared peridotite xenoliths are snapshots of deformation processes that occur in the cratonic mantle shortly before their entrainment by kimberlites. The process of deformation that caused the shearing has, however, been highly debated since the 1970s and remains uncertain. To investigate the processes involved in the deformation, we have studied twelve sheared peridotites from Late Cretaceous (90
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Himalayan-like crustal melting and differentiation in the southern North American Cordilleran anatectic belt during the Laramide orogeny: Coyote Mountains, Arizona J. Petrol. (IF 3.9) Pub Date : 2023-10-05 James B Chapman, Cody Pridmore, Kevin Chamberlain, Gordon Haxel, Mihai Ducea
The southern U.S. and northern Mexican Cordillera experienced crustal melting during the Laramide orogeny (ca. 80-40 Ma). The metamorphic sources of melt are not exposed at the surface, however, anatectic granites are present throughout the region, providing an opportunity to investigate the metamorphic processes associated with this orogeny. A detailed geochemical and petrochronological analysis of
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The Influence of Undercooling and Sector Zoning on Clinopyroxene–Melt Equilibrium and Thermobarometry J. Petrol. (IF 3.9) Pub Date : 2023-10-03 Alice MacDonald, Teresa Ubide, Silvio Mollo, Alessio Pontesilli, Matteo Masotta
Thermobarometry provides a critical means of assessing locations of magma storage and dynamics in the lead up to volcanic eruptions and crustal growth. A common approach is to utilise minerals which have compositions sensitive to changes in pressure and/or temperature, such as clinopyroxene which is ubiquitous in mafic to intermediate magmas. However, clinopyroxene thermobarometry may carry significant
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Petrology and geochemistry of Adak Island plutonic xenoliths: implications for primitive magma generation and crustal differentiation in the Aleutian Island arc J. Petrol. (IF 3.9) Pub Date : 2023-10-02 Emma S Sosa, Claire E Bucholz, Mattison H Barickman, Jill A VanTongeren, Jacob B Setera, Suzanne Mahlburg Kay, Robert W Kay
Deep crustal cumulates in arcs offer a window into the chemistry and crystallization conditions (P-T-H2O-fO2) of primitive basalts in the upper mantle and lower crust and can be studied in ancient exhumed terranes or in xenoliths erupted in young arc lavas. Here, we expand on previous studies and thoroughly characterize the extensive xenolith suites erupted from the Mt. Moffett and Mt. Adagdak volcanic
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Bulk compositional influence on diverse metapelitic mineral assemblages in the Whetstone Lake area, Ontario J. Petrol. (IF 3.9) Pub Date : 2023-09-19 Jacob B Forshaw, David R M Pattison
Understanding the interplay between bulk composition and metamorphic grade underpins our interpretations of metamorphism in orogenic belts. The focus of this study is the regional garnet-staurolite-kyanite-sillimanite metamorphic sequence of the Whetstone Lake area, southeastern Ontario. In the kyanite and lower sillimanite zones of this area, there is exceptional diversity in metapelitic mineral assemblages
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Experimental constraints on the ferric Fe content and oxygen fugacity in subducted serpentinites J. Petrol. (IF 3.9) Pub Date : 2023-09-16 Lisa Eberhard, Daniel J Frost, Catherine A McCammon, David Dolejš, James A D Connolly
Serpentinites play an important role in the delivery of water into subduction zones. In addition, serpentinites also contain ferric Fe and can transport significant redox potential. We present high-pressure and high-temperature experiments and Mössbauer spectroscopy measurements on natural lizardite and antigorite samples equilibrated at various oxygen fugacities in order to quantify the relationship
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Large-scale Cretaceous adakitic magmatism induced by water-fluxed melting of continental crust during the North China Craton destruction J. Petrol. (IF 3.9) Pub Date : 2023-09-06 Shuo Xue, Wanzhu Zhang, Ming-Xing Ling, Weidong Sun, Xing Ding
The mechanism behind the destabilization of the North China Craton (NCC) remains a contentious topic among researchers. Large-scale Cretaceous adakitic magmatism in the NCC offers insights into the decratonization process. This study focuses on the Huashan and Laoniushan plutons located in the Lesser Qinling on the southern margin of the NCC and compiles published data for coeval adakitic rocks to
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Ten thousand years of magma storage preceding the last caldera-forming eruption of the Bandelier magmatic system, New Mexico, USA J. Petrol. (IF 3.9) Pub Date : 2023-09-06 Nicholas F Meszaros, James E Gardner, Matthew J Zimmerer, Kenneth S Befus
In this study, we present new evidence for changes in magma storage conditions that preceded the 1232 ka caldera-forming eruption of the Bandelier magmatic system in the Jemez Mountains Volcanic Field. Using high precision 40Ar/39Ar sanidine dating we determine that at least eight rhyolites erupted within 8.6 ± 3.4 kyr of the ~400 km3 eruption that formed Valles caldera. Some of those rhyolites contain
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Contrasting styles of lower crustal metamorphism from a granulite suite of rocks from Angul, Eastern Ghats Belt, India: Implications for the India-Antarctica correlation J. Petrol. (IF 3.9) Pub Date : 2023-08-31 Aparupa Banerjee, Proloy Ganguly, Kaushik Das, Nilanjana Sorcar, Sankar Bose
The present work is focussed on a suite of high-grade rocks including mafic granulite, aluminous granulite, khondalite, charnockite, and augen gneiss along with medium-grade rocks like olivine-bearing metanorite, gabbro, and porphyritic granite of the Angul domain at the northern margin of the Proterozoic Eastern Ghats Province. Based on the petrological and geothermobarometric data, two distinct metamorphic
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Application of an Improved Olivine-Melt Thermometer/Hygrometer to the Colima Cone Basanites and Minettes of Western Mexico: Implications for the Mantle Source of Unusually High-MgO Melts J. Petrol. (IF 3.9) Pub Date : 2023-08-27 Xiaofei Pu, Rebecca A Lange, Gordon M Moore
A collection of Quaternary, high-MgO (≤13.4 wt%) basanite and minette cinder and lava cones, with an enhanced arc geochemical signature, are located along the northern margin of the N-S Colima rift in western Mexico. The Colima rift overlies the lithospheric suture between the Jalisco block and Guerrero terrane, as well as the tear between the Rivera and Cocos subducting oceanic plates. From the literature
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A high-δ18O mantle source for the 2.06 Ga Phalaborwa Igneous Complex, South Africa? J. Petrol. (IF 3.9) Pub Date : 2023-08-23 Joshua Munro, Chris Harris
The 2060 ± 2 Ma Phalaborwa Complex is a pipe-like, ultramafic to carbonatite intrusion formed from multiple magma pulses. The complex is made up of a main pipe consisting of clinopyroxenites, ultramafic pegmatoids, carbonatites and foskorite (olivine-apatite-magnetite-calcite assemblage), surrounded by many smaller syenite plugs. The range in mineral δ18O values for all rock types and minerals analysed
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Miocene Volcanism of the Baikal Rift across the Boundary of the Siberian Craton: Evidence for Lithospheric Mantle Melting J. Petrol. (IF 3.9) Pub Date : 2023-08-22 Elena I Demonterova, Alexei V Ivanov, Valery M Savatenkov, Mei-Fei Chu, Svetlana V Panteeva, Hao-Yang Lee, Ilya N Bindeman
Continental rifting is usually viewed in terms of two contrasting models of active and passive extension. The origin of the Baikal Rift, adjacent to the southern part of the Siberian Craton, has been described by both models in the past. It is expected that basaltic magmatism in an active model scenario should be primarily sourced from a mantle plume or plume-fed asthenosphere, whereas melting of the
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Magnesian Andesites from Kibblewhite Volcano in the Kermadec Arc, New Zealand J. Petrol. (IF 3.9) Pub Date : 2023-08-16 Yasuhiro Hirai, Yoshihiko Tamura, Tomoki Sato, Takashi Miyazaki, Qing Chang, Bogdan S Vaglarov, Jun-Ichi Kimura, Kaj Hoernle, Reinhard Werner, Folkmar Hauff, Christian Timm
Primary andesitic magmas could be an important component of arc magma genesis and might have played a key role in the advent of continents. Recent studies hypothesized that primary andesitic magmas occur in the oceanic arc, where the crust is thin. The Kermadec arc has the thinnest crust among all the studied oceanic arcs (<15 km in thickness); however, there are no studies that corroborate the formation
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The Strontian Intrusive Complex: Petrography, Thermobarometry and the Influence of Titanite on Residual Melt Chemistry J. Petrol. (IF 3.9) Pub Date : 2023-08-14 Thomas J Matthews, Matthew A Loader, Jamie J Wilkinson, Yannick Buret, Simon J E Large, Elliott A Birt
Although the evolution of residual melts in magmatic systems controls their eruptability and ore-forming potential, their compositions are obscured in plutonic rocks by a protracted near-solidus evolution, and the absence of interstitial glass. Here, we trace the evolution of residual melt compositions in rocks from the Strontian Intrusive Complex, Scotland, using the trace element chemistry of amphiboles
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Apatite CO2 and H2O as Indicators of Differentiation and Degassing in Alkaline Magmas J. Petrol. (IF 3.9) Pub Date : 2023-08-10 Jian-Hui Su, Xin-Fu Zhao, Johannes Hammerli
Apatite can incorporate significant amounts of H2O and CO2, potentially recording volatile abundance and behavior during magma evolution. Here we conducted in situ measurements of CO2 and H2O concentrations in apatite, along with elemental compositions, from two contemporaneous alkaline volcanic suites (Tianbao and Tudiling) in the South Qinling belt in central China to better understand the CO2 and
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Melt diffusion-moderated crystal growth and its effect on euhedral crystal shapes J. Petrol. (IF 3.9) Pub Date : 2023-08-08 Martin F Mangler, Madeleine C S Humphreys, Eshbal Geifman, Alexander A Iveson, Fabian B Wadsworth, Richard A Brooker, Amanda Lindoo, Keiji Hammond
Crystal growth is often described as either interface-controlled or diffusion-controlled. Here, we study crystal growth in an intermediate scenario where reaction rates at the crystal-melt interface are similar to the rates of diffusive transport of ions through the melt to the advancing crystal surface. To this end, we experimentally investigated euhedral plagioclase crystal shapes in dry mafic (basaltic)
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Flare up of hot-dry-reduced ignimbrites related to extension in the Cascades Arc: the Deschutes Formation, central Oregon J. Petrol. (IF 3.9) Pub Date : 2023-08-08 Bradley W Pitcher, Anita L Grunder, Adam J R Kent
Ignimbrite flare-ups are rare periods of intense silicic volcanism during which the pyroclastic volume and eruptive frequency is more than an order of magnitude higher than background activity. Investigating the compositional differences between flare-up and steady-state magmas provides critical constraints on the petrogenetic causes for the event and can offer unique opportunities to investigate the
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Reappraising Crystallization Kinetics with Overgrowth Chronometry: An In Situ Study of Olivine Growth Velocities J. Petrol. (IF 3.9) Pub Date : 2023-08-02 Benoît Welsch, François Faure, Emily C First
We investigated the early stages of olivine crystal growth via in situ seeded experiments in a single plagioclase-hosted melt inclusion, using a heating stage microscope. Each experiment was subjected to a cooling ramp of 7800 °C/h followed by an isothermal dwell at 19, 38, 57, 77, 96 or 129 °C of undercooling. The seeds (6 – 16 μm in diameter Ø) grew into large crystals (Ø 80 – 169 μm) in 3 to 30
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Rapid Recycling of Subducted Sediments in the Subcontinental Lithospheric Mantle J. Petrol. (IF 3.9) Pub Date : 2023-08-02 Jian Wang, Qiang Wang, Lin Ma, Wan-Long Hu, Jun Wang, Elena Belousova, Gong-Jian Tang
Subduction recycling of sediments plays a key role in the geochemical evolution of Earth. The presence of recycled terrigenous sediments in upwelling plumes has been cited to explain the EM2 signature in ocean island volcanics, characterized by particularly high 87Sr/86Sr (>0.706). However, the origin of such isotopic anomalies in continental regions and the role of subducted sediments in the subcontinental
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Geochemical Anatomy of the Main Magnetitite Layer, Bushveld Complex, South Africa J. Petrol. (IF 3.9) Pub Date : 2023-08-02 Richard Grant Cawthorn, Terence Sinclair McCarthy
The mafic layered Bushveld Complex, South Africa, contains numerous examples of monomineralic layers within its succession. The Upper Zone (UZ) contains approximately 24 magnetitite layers, the genesis of which have been extensively debated. The Main Magnetitite Layer (MML) is approximately 2 m thick and is traceable around its edge across >60,000 km2. Its basal contact with underlying anorthosite
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Crustal growth identified by high-δ18O zircon and olivine: A perspective from ultramafic arc cumulates in southern Tibet J. Petrol. (IF 3.9) Pub Date : 2023-07-22 Jun Wang, Qiang Wang, Peng Sun, Wei Dan, Andrew C Kerr, Zhi-Ping Zhang, Le Zhang, Gangjian Wei, Han Dong, Wan-Long Hu, Zong-Yong Yang, Xiu-Zheng Zhang, Yue Qi
In recent studies of crustal growth using global zircon Hf–O isotopic datasets, high-δ18O zircons are typically attributed to intra-crustal reworking during which very little juvenile mantle-derived magmas were added to the crust. Although arc magmas may originate from a high-δ18O mantle wedge, it has been difficult to decipher the contribution of high-δ18O mantle to zircon-saturated felsic magma due
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Iron isotope systematics of the Skaergaard intrusion and implications for its liquid line of descent J. Petrol. (IF 3.9) Pub Date : 2023-07-21 Charles E Lesher, Eric L Brown, Gry H Barfod, Justin Glessner, Niklas Stausberg, Peter Thy, Christian Tegner, Lars Peter Salmonsen, Troels F D Nielsen
The Skaergaard intrusion is one of the most thoroughly studied layered mafic intrusions on Earth and an exceptional example of (near) closed-system magmatic differentiation. We report new Fe isotope data for whole rocks, and magnetite and ilmenite separates through the layered series (LS) and upper border series (UBS) of the intrusion. δ56Fe values for gabbroic rocks range from 0.033 to 0.151 ‰ with
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Barometers behaving badly II: A critical evaluation of Cpx-only and Cpx-Liq thermobarometry in variably-hydrous arc magmas J. Petrol. (IF 3.9) Pub Date : 2023-07-05 Penny E Wieser, Adam J R Kent, Christy B Till
The chemistry of erupted clinopyroxene crystals (±equilibrium liquids) have been widely used to deduce the pressures and temperatures of magma storage in volcanic arcs. However, the large number of different equations parameterizing the relationship between mineral and melt compositions and intensive variables such as pressure and temperature yield vastly different results, with implications for our
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Into the high to ultrahigh temperature melting of Earth’s crust: Investigation of melt and fluid inclusions within Mg–rich metapelitic granulites from the Mather Peninsula, East Antarctica J. Petrol. (IF 3.9) Pub Date : 2023-06-30 Zhao Liu, Bruna B Carvalho, Wancai Li, Laixi Tong, Omar Bartoli, Longyao Chen, Qinghe Yan, Haobo Wu
Precise constraints on the compositions of melts generated by anatexis under ultrahigh temperature (UHT) conditions are critical for understanding processes of partial melting and differentiation of the Earth’s crust. Here we reveal geochemical and physical signatures of anatectic melts preserved as nanogranitoids (i.e. crystalized melt inclusions) within sapphirine–bearing UHT metapelitic granulites
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A mush-facilitated magma mixing process revealed by complex zoning of plagioclase in mafic magmatic enclaves of the Early Cretaceous Sanguliu granitic pluton, East China J. Petrol. (IF 3.9) Pub Date : 2023-06-29 Zisong Zhao, Christina Yan Wang, Jingzhao Dou, Bo Wei
Mafic magmatic enclaves (MMEs) hosted in granitic plutons are ideal to investigate the role of mushes on magma mixing processes in crustal magma chambers. However, the petrographic evidence for mixing of magmas through infiltration and percolation in coexisting mushes and magmas is desired. Here, we describe complex zoning patterns of plagioclase in the MMEs hosted in the monzogranite of the Early
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The origin and evolution of DMM-like lithospheric mantle beneath continents: Mantle xenoliths from the Oku Volcanic Group in the Cameroon Volcanic Line, West Africa J. Petrol. (IF 3.9) Pub Date : 2023-06-29 Jacek Puziewicz, Sonja Aulbach, Mary-Alix Kaczmarek, Theodoros Ntaflos, Axel Gerdes, Hubert Mazurek, Anna Kukuła, Magdalena Matusiak-Małek, Sylvin S T Tedonkenfack, Małgorzata Ziobro-Mikrut
The lithospheric mantle as sampled by peridotite xenoliths in some continental settings resembles the source of mid-ocean ridge basalts (MORB). Whether this resemblance is a primary feature or the result of post-formation secondary processes remains controversial. Here, the age, origin and thermochemical evolution of fertile continental mantle are constrained based on the chemical composition of minerals
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Effects of H2O-CO2 Fluids, Temperature, and Peridotite Fertility on Partial Melting in Mantle Wedges and Generation of Primary Arc Basalts J. Petrol. (IF 3.9) Pub Date : 2023-06-27 Michael Lara, Rajdeep Dasgupta
Many lines of evidence from high P-T experiments, thermodynamic models, and natural observations suggest that slab-derived aqueous fluids, which flux mantle wedges contain variable amounts of dissolved carbon. However, constraints on the effects of H2O-CO2 fluids on mantle melting, particularly at mantle wedge P-T conditions, are limited. Here we present new piston cylinder experiments on fertile and
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Mineralogy and geochemistry of nepheline syenite from the Bang Phuc massif of the alkaline Cho Don complex in north-eastern Vietnam – implications for magma evolution and fluid-rock interactions J. Petrol. (IF 3.9) Pub Date : 2023-06-22 M Dumańska-Słowik, T Powolny, G Nguyen Khac
The alkaline Cho Don complex in NE Vietnam comprises several mafic-felsic suites related to the widespread magmatism developed during the early-Permian–late-Triassic. The contribution explores the petrogenesis of nepheline syenite from the Bang Phuc massif and its petrogenetic relationship with cogenetic scapolite-rich gabbro. The nepheline syenite formed through fractional crystallization of pristine
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Developing an Integrated Petrogenetic Model for Understanding REE Deportment of the Ampasibitika Intrusion and Associated Ion Adsorption Deposits J. Petrol. (IF 3.9) Pub Date : 2023-06-22 E Marquis, K M Goodenough, M P Smith, G Estrade, F Rasolonirina, R L Rakotoson
Alkaline-peralkaline igneous systems are promising sources of Rare Earth Elements (REE). Preservation bias has resulted in a gap in the geological record for alkaline-peralkaline magmatic systems, with the hypabyssal plumbing system linking magma chambers to extrusive volcanic rocks poorly represented. Large plutonic varieties of these systems are often proposed to have fed (now eroded) volcanoes,