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Ni-in-garnet geothermometry in mantle rocks: a high pressure experimental recalibration between 1100 and 1325 °C Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-04-07 Z. J. Sudholz, G. M. Yaxley, A. L. Jaques, J. Chen
The temperature-dependent exchange of Ni and Mg between garnet and olivine in mantle peridotite is an important geothermometer for determining temperature variations in the upper mantle and the diamond potential of kimberlites. Existing calibrations of the Ni-in-garnet geothermometer show considerable differences in estimated temperature above and below 1100 °C hindering its confident application.
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Origin of the primitive, strongly SiO 2 -undersaturated alkalic rocks from the Deccan Traps by low-degree mantle melting and high-pressure fractional crystallization Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-04-03 Nilanjan Chatterjee
Strongly SiO2-undersaturated alkalic rocks (Mg# > 50, SiO2 ≤ 45 wt%, Na2O + K2O ≥ 3 wt%) occur in three early-stage (Sarnu-Dandali, Mundwara, Bhuj) and one late-stage (Murud-Janjira) rift-associated volcanic complexes in the Cretaceous-Paleogene Deccan Traps flood basalt province of India. Thermobarometry based on clinopyroxene-liquid equilibrium suggests that they mostly crystallized beneath the Moho
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Experimental settling, floatation and compaction of plagioclase in basaltic melt and a revision of melt density Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-31 Giuliano Krättli, Max W. Schmidt
Centrifuge-assisted piston cylinder experiments were conducted on plagioclase in basaltic melt at 1140–1250 °C, 0.42–0.84 GPa and mostly 1000 g. One set of experiments assesses the settling velocity of a dilute plagioclase suspension; a second sinks or floats plagioclase in a MORB-type melt exploring conditions of neutral buoyancy; and a third set examines floatation of plagioclase from an evolved
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Sources of auriferous fluids associated with a Neoarchean BIF-hosted orogenic gold deposit revealed by the multiple sulfur isotopic compositions of zoned pyrites Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-31 Li Liu, Trevor R. Ireland, Peter Holden, Janaina Ávila, Paulo Vasconcelos, John Mavrogenes
Internal textures, multiple sulfur isotopic compositions, and contents of gold, selenium, and molybdenum of ore-related pyrites from a Neoarchean carbonate-facies BIF-hosted gold deposit in Quadrilátero Ferrífero were investigated to elucidate the source(s) of sulfur. Sodium hypochlorite etching and BSE imaging revealed pervasive zoning in pyrites. Five different growth zones (Py1a, Py1b, Py2, Py3
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Serial interaction of primitive magmas with felsic and mafic crust recorded by gabbroic dikes from the Antarctic extension of the Karoo large igneous province Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-30 Jussi S. Heinonen, Arto V. Luttinen, Frank J. Spera, Saku K. Vuori, Wendy A. Bohrson
Two subvertical gabbroic dikes with widths of ~ 350 m (East-Muren) and ≥ 500 m (West-Muren) crosscut continental flood basalts in the Antarctic extension of the ~ 180 Ma Karoo large igneous province (LIP) in Vestfjella, western Dronning Maud Land. The dikes exhibit unusual geochemical profiles; most significantly, initial (at 180 Ma) εNd values increase from the dike interiors towards the hornfelsed
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Corundum-quartz metastability: the influence of a nanometer-sized phase on mineral equilibria in the system Al 2 O 3 –SiO 2 –H 2 O Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-23 Dina S. Schultze, Richard Wirth, Bernd Wunder, Anselm Loges, Max Wilke, Gerhard Franz
The metastable paragenesis of corundum and quartz is rare in nature but common in laboratory experiments where according to thermodynamic predictions aluminum–silicate polymorphs should form. We demonstrate here that the existence of a hydrous, silicon-bearing, nanometer-thick layer (called “HSNL”) on the corundum surface can explain this metastability in experimental studies without invoking unspecific
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Hydrogen, trace, and ultra-trace element distribution in natural olivines Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-19 Sylvie Demouchy, Olivier Alard
We investigate the coupling between H, minor, trace, and ultra-trace element incorporations in 17 olivines from ten different locations covering various petrological origins: magmatic, hydrothermal, and mantle-derived context. Concentrations in major element are determined by micro X-ray fluorescence. Minor, trace, and ultra-trace elements are determined by laser ablation inductively coupled plasma
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Evidence supporting micro-galvanic coupling in sulphides leads to gold deposition Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-12 Jamie S. Laird, Angel Halfpenny, Chris G. Ryan, Weihua Liu
Electrical micro-junctions in metal sulfides drive electrochemical reactions with passing gold-bearing fluids, resulting in the deposition of gold, even from under-saturated ore fluids. Understanding the role micro-junctions play in the deposition of gold requires (a) imaging the electric field distribution of a galvanic couple near the surface to qualify the existence of an active micro-geo-battery
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What can we learn from REE abundances in clinopyroxene and orthopyroxene in residual mantle peridotites? Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-09 Yan Liang, Zejia Ji, Boda Liu
Clinopyroxene and orthopyroxene are the two major repositories of rare-earth elements (REE) in spinel peridotites. Most geochemical studies of REE in mantle samples focus on clinopyroxene. Recent advances in in situ trace element analysis have made it possible to measure REE abundance in orthopyroxene. The purpose of this study is to determine what additional information one can learn about mantle
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A new activity model for Fe–Mg–Al biotites: II—Applications in the K 2 O–FeO–MgO–Al 2 O 3 –SiO 2 –H 2 O (KFMASH) system Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-04 Edgar Dachs, Stan Roozen, Artur Benisek
The new biotite activity model and standard-state thermodynamic properties of Ann, Phl, and Eas presented in part-I were used to make pseudosections of bulk compositions representing experimental Fe–Mg exchange equilibria and (model) pelitic bulk rock compositions in the system K2O–FeO–MgO–Al2O3–SiO2–H2O (KFMASH), using mainly the software Perple_X. These pseudosection calculations (termed ‘our calculation(s)’
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Phase heritage during replacement reactions in Ti-bearing minerals Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-04 Mark Pearce, Angela Escolme
Replacement reactions occur during metamorphism and metasomatism in response to changes in pressure, temperature and bulk rock and fluid compositions. To interpret the changes in conditions, it is necessary to understand what phases have previously been present in the rocks. During fluid-mediated replacement, the crystallography of the replacement phases is often controlled by the parent reactant phase
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A new activity model for Fe–Mg–Al biotites: I—Derivation and calibration of mixing parameters Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-04 Edgar Dachs, Artur Benisek
A new activity model for Fe–Mg–Al biotites is formulated, which extends that of Mg–Al biotites (Dachs and Benisek, Contrib Mineral Petrol 174:76, 2019) to the K2O–FeO–MgO–Al2O3–SiO2–H2O (KFMASH) system. It has the two composition variables XMg = Mg/(Mg + Fe2+) and octahedral Al, and Fe–Mg and Mg–Al ordering variables resulting in five linearly independent endmembers: annite (Ann, K[Fe]M1[Fe]2M2[Al0
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Recycling of subducted Indian continental crust and its significance on post-collisional ultrapotassic magmatism in southwestern Tibet Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-03-01 Izhar Sadiq, Fa-Bin Pan, Hong-Fei Zhang, Chun-Feng Li, Biji Luo, Mohammad Arif
The petrogenesis of the Eocene (43–42 Ma) Nb-rich granitoid dykes from the Kohistan–Ladakh island arc provides insights into melting of the down-going Indian continental crust during the Indian-Eurasian continental collision. These Nb-rich granitoids (SiO2 = 53.8–72.3 wt%, Nb = 24.0–44.1 ppm) have high Sr/Y (41.2–76.8) and (La/Yb)N (15.6–36.8) ratios. Their geochemical and Sr–Nd–Hf isotopic compositions
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The redox dependence of titanium isotope fractionation in synthetic Ti-rich lunar melts Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-02-28 Laura J. A. Rzehak, Sebastian Kommescher, Florian Kurzweil, Peter Sprung, Felipe P. Leitzke, Raúl O. C. Fonseca
Equilibria between Ti oxides and silicate melt lead to Ti isotope fractionation in terrestrial samples, with isotopically light Ti oxides and isotopically heavy coexisting melt. However, while Ti is mostly tetravalent in terrestrial samples, around 10% of the overall Ti is trivalent at fO2 relevant to lunar magmatism (~ IW-1). The different valences of Ti in lunar samples, could additionally influence
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Zircon stability grids in crustal partial melts: implications for zircon inheritance Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-02-24 Fernando Bea, Irene Morales, José Francisco Molina, Pilar Montero, Aitor Cambeses
Zircon inheritance is a common phenomenon in igneous rocks, although more frequent in granitoids. Zircons inherited from granite magmas mostly come from the source, not from wall rocks or xenoliths. Consequently, they can provide invaluable information about the source materials, melting temperature, and melt segregation conditions. Miller et al. (Geology 31:529–532, 2003) divided granite rocks according
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Rapid reduction of basaltic glasses in piston-cylinder experiments: a XANES study Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-02-09 Peng Ni, Youxue Zhang, Adrian Fiege, Matthew Newville, Antonio Lanzirotti
Graphite capsules are commonly used in high-temperature, high-pressure experiments, particularly for nominally anhydrous experiments and iron-bearing silicate samples. Due to the presence of graphite in the sample assembly, the oxygen fugacity for these experiments is thought to be relatively low, typically at or below the graphite-CO-CO2 buffer (CCO). The detailed mechanism and kinetics of redox control
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Petrogenesis of the Loch Bà ring-dyke and Centre 3 granites, Isle of Mull, Scotland Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-02-09 Valentin R. Troll, Graeme R. Nicoll, Robert M. Ellam, C. Henry Emeleus, Tobias Mattsson
The Loch Bà ring-dyke and the associated Centre 3 granites represent the main events of the final phase of activity at the Palaeogene Mull igneous complex. The Loch Bà ring-dyke is one of the best exposed ring-intrusions in the world and records intense interaction between rhyolitic and basaltic magma. To reconstruct the evolutionary history of the Centre 3 magmas, we present new major- and trace-element
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Fluid inclusion induced hardening: nanoscale evidence from naturally deformed pyrite Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-02-05 Renelle Dubosq, A. Rogowitz, D. A. Schneider, K. Schweinar, B. Gault
The interaction of trace elements, fluids and crystal defects plays a vital role in a crystalline material’s response to an applied stress. Fluid inclusions are typically known to facilitate crystal-plastic deformation in minerals. Herein we discuss a model of fluid hardening, whereby dislocations are pinned at fluid inclusions during crystal-plastic deformation, initiating pipe diffusion of trace
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Exhumation dynamics of high-pressure metamorphic rocks from the Voltri Unit, Western Alps: constraints from phengite Rb–Sr geochronology Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-02-02 Andrew J. Smye, Spencer M. Seman, Marco Scambelluri, Paul G. Starr, Laura Federico
The Voltri Unit and adjacent Tertiary Piedmont Basin, Western Alps, preserve complementary bedrock and sedimentary archives of Alpine subduction and exhumation. Combined PT modeling and phengite Rb–Sr geochronology of bedrock and clast samples shows that Fe–Ti metagabbros and metasediments preserve a record of protracted high-pressure metamorphism, between ~ 50 and ~ 40 Ma. Bedrock and clast Fe–Ti
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Chemical and textural diversity of Kameni (Greece) dacites: role of vesiculation in juvenile and mature basal crystal masses Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-28 Michael D. Higgins, Anouk Debecq, Jacqueline Vander Auwera, Paraskevi Nomikou
Dacite lavas erupted from Kameni Islands volcanic centre (Greece) during the last 2000 years have a limited range in chemical composition (SiO2 = 64.0–68.5%) which contrasts with their wide range in plagioclase abundance (3–22%) and crystal size distributions. Most plagioclase crystals have simple zoning and occur independently or in loose clusters with finer-grained cores. We propose that magmatic
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Experimental recalibration of the Cr-in-clinopyroxene geobarometer: improved precision and reliability above 4.5 GPa Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-28 Z. J. Sudholz, G. M. Yaxley, A. L. Jaques, G. P. Brey
The pressure dependence of the exchange of Cr between clinopyroxene and garnet in peridotite is applicable as a geobarometer for mantle-derived Cr-diopside xenocrysts and xenoliths. The most widely used calibration (Nimis and Taylor Contrib Miner Petrol 139: 541–554, 2000; herein NT00) performs well at pressures below 4.5 GPa, but has been shown to consistently underestimate pressures above 4.5 GPa
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From long-lived batholith construction to giant porphyry copper deposit formation: petrological and zircon chemical evolution of the Quellaveco District, Southern Peru Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-28 Chetan L. Nathwani, Adam T. Simmons, Simon J. E. Large, Jamie J. Wilkinson, Yannick Buret, Christian Ihlenfeld
Porphyry Cu ore deposits are a rare product of arc magmatism that often form spatiotemporal clusters in magmatic arcs. The petrogenetic evolution of igneous rocks that cover the temporal window prior to and during porphyry Cu deposit formation may provide critical insights into magmatic processes that are key in generating these systems. This study documents the magmatic evolution of the Palaeocene–Eocene
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Whiteschist genesis through metasomatism and metamorphism in the Monte Rosa nappe (Western Alps) Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-10 Cindy Luisier, Lukas P. Baumgartner, Benita Putlitz, Torsten Vennemann
Whiteschists from the Monte Rosa Nappe were examined in the field as well as with petrographic, geochemical, and isotopic methods to constrain the controversial origin of these rocks in their Alpine metamorphic context. Whiteschists occur as ellipsoidal-shaped, decametric-sized bodies, within a Permian metagranite, and consist mainly of chloritoid, talc, phengite, and quartz. The transition from whiteschist
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Persistent gas emission originating from a deep basaltic magma reservoir of an active volcano: the case of Aso volcano, Japan Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-10 Masataka Kawaguchi, Toshiaki Hasenaka, Kenneth T. Koga, Estelle F. Rose-Koga, Atsushi Yasuda, Natsumi Hokanishi, Yasushi Mori, Kenji Shimizu, Takayuki Ushikubo
Volcanic gas emission is considered to reflect the degassing of magma beneath volcanoes. The combined observations of gas measurement and petrological study are expected to constrain the volatile concentrations and storage depths of the pre-eruptive and primitive magma. Aso volcano (Japan) is a constantly-monitored, persistently-degassing volcano, and an ideal site to acquire gas and petrologic data
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Dual mixing for the formation of Neoproterozoic granitic intrusions within the composite Jiuling batholith, South China Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-10 Di Wang, Xiao-Lei Wang
Granite batholiths record the processes that occur during the formation and differentiation of the continental crust. The ~ 4000 km2 composite Neoproterozoic Jiuling batholith is one of the largest batholiths in southern China and consists of four peraluminous granitoid intrusions that were emplaced at ca. 828–810 Ma. These granitoids define a trend that moves from the terrestrial towards the seawater
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Testing solution models for phase equilibrium (forward) modeling of partial melting experiments Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-10 Félix Gervais, Pierre-Henri Trapy
This study compares four sets of solution (or activity-composition) models using two internally consistent thermodynamic datasets for calculating isochemical phase diagram sections of six partial melting experiments covering a wide range of metasedimentary bulk compositions. Compared parameters are: (1) biotite-breakdown temperatures; (2) parageneses of Fe–Mg phases and Ti-oxides; (3) proportion of
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Thermal equation of state of phase egg (AlSiO 3 OH): implications for hydrous phases in the deep earth Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-10 Yungui Liu, Rong Huang, Ye Wu, Dongzhou Zhang, Junfeng Zhang, Xiang Wu
Phase egg (AlSiO3OH), an important hydrous phase in the Al2O3–SiO2–H2O ternary system, was found in the superdeep diamond from the mantle transition zone. Here, we have investigated the compressibility and the crystal structural evolution of phase egg using the synchrotron-based single-crystal X-ray diffraction and infrared spectroscopy combined with diamond anvil cells up to 32 GPa and 900 K. Present
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Zircon petrochronology in large igneous provinces reveals upper crustal contamination processes: new U–Pb ages, Hf and O isotopes, and trace elements from the Central Atlantic magmatic province (CAMP) Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-10 J. H. F. L. Davies, A. Marzoli, H. Bertrand, N. Youbi, M. Ernesto, N. D. Greber, M. Ackerson, G. Simpson, A.-S. Bouvier, L. Baumgartner, T. Pettke, F. Farina, H. V. Ahrenstedt, U. Schaltegger
Zircon occasionally crystallizes in evolved melt pockets in mafic large igneous province (LIP) magmas, and in these cases, it is used to provide high-precision age constraints on LIP events. The precision and accuracy of high-precision ages from LIPs are crucially important, because they may be implicated in mass extinctions. However, why zircon crystallizes in these magmas is not clearly understood
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Idiomorphic oikocrysts of clinopyroxene produced by a peritectic reaction within a solidification front of the Bushveld Complex Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2021-01-10 Stephen J. Barnes, Rais Latypov, Sofya Chistyakova, Bélinda Godel, Louise E. Schoneveld
Orthopyroxenite cumulates throughout the Critical Zone of the Bushveld Complex commonly contain prominent euhedral crystals of bottle-green augite, typically around 1 cm in size and surrounded by “haloes” of nearly pure plagioclase. On close examination, the augite grains can be seen to be oikocrysts, containing extensively resorbed chadacrysts of orthopyroxene, indicating an effective peritectic reaction
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Formation of Bushveld anorthosite by reactive porous flow Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-12-23 W. D. Maier, S.-J. Barnes, D. Muir, D. Savard, Y. Lahaye, W. D. Smith
Bushveld anorthosites commonly contain the so-called “mottles” comprising irregular, typically centimetric domains of oikocrystic pyroxene or olivine enclosing small, embayed plagioclase grains. The mottles were traditionally interpreted to result from solidification of trapped intercumulus liquid or via in situ crystallisation at the top of the crystal mush. Here, we present microtextural and compositional
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Formation mechanisms of macroscopic globules in andesitic glasses from the Izu–Bonin–Mariana forearc (IODP Expedition 352) Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-12-23 Raúl O. C. Fonseca, Lina T. Michely, Maria Kirchenbaur, Julie Prytulak, Jeffrey Ryan, Kerstin Hauke, Felipe P. Leitzke, Renat R. Almeev, Chris S. Marien, Axel Gerdes, Rico Schellhorn
The Izu–Bonin–Mariana volcanic arc is situated at a convergent plate margin where subduction initiation triggered the formation of MORB-like forearc basalts as a result of decompression melting and near-trench spreading. International Ocean Discovery Program (IODP) Expedition 352 recovered samples within the forearc basalt stratigraphy that contained unusual macroscopic globular textures hosted in
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Formation of Mg-carbonates and Mg-hydroxides via calcite replacement controlled by fluid pressure Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-11-23 Gan Duan, Joël Brugger, Barbara Etschmann, Rahul Ram, Andrew Frierdich, Steven Micklethwaite
Reactive fluid flow can control the mineralogical, mechanical and chemical evolution of the Earth’s crust. When rocks are exposed to differential stresses (i.e., vertical stress ≠ horizontal stress ≠ pore-fluid pressure (Pf)) during reactive fluid flow, effective pressure is usually assumed to control the overall reaction process. Here, we show that fluid pressure can play an important role in mineral
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A unifying basis for the interplay of stress and chemical processes in the Earth: support from diverse experiments Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-11-19 John Wheeler
The interplay between stress and chemical processes is a fundamental aspect of how rocks evolve, relevant for understanding fracturing due to metamorphic volume change, deformation by pressure solution and diffusion creep, and the effects of stress on mineral reactions in crust and mantle. There is no agreed microscale theory for how stress and chemistry interact, so here I review support from eight
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Evidence for superhydrous primitive arc magmas from mafic enclaves at Shiveluch volcano, Kamchatka Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-11-18 Andrea E. Goltz, Michael J. Krawczynski, Maxim Gavrilenko, Natalia V. Gorbach, Philipp Ruprecht
Mafic enclaves preserve a record of deep differentiation of primitive magmas in arc settings. We analyze the petrology and geochemistry of mafic enclaves from Shiveluch volcano in the Kamchatka peninsula to determine the differentiation histories of primitive magmas and to estimate their pressures, temperatures, and water contents. Amphibole inclusions in high forsterite olivine suggest that the primitive
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Electrical conductivity of HCl-bearing aqueous fluids to 700 ºC and 1 GPa Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-11-18 Steffen Klumbach, Hans Keppler
Subsurface magmatic–hydrothermal systems are often associated with elevated electrical conductivities in the Earthʼs crust. To facilitate the interpretation of these data and to allow distinguishing between the effects of silicate melts and fluids, the electrical conductivity of aqueous fluids in the system H2O–HCl was measured in an externally heated diamond anvil cell. Data were collected to 700 °C
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Controls on development of different mineral assemblages in gabbro and basalt during subduction metamorphism Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-11-11 Patricia Kang, Katherine F. Fornash, Donna L. Whitney
Coexisting fine-grained (meta-volcanic) and coarse-grained (meta-plutonic) mafic rocks in a high-pressure (P)/low-temperature (T) complex (Sivrihisar, Turkey) preserve different prograde, peak, and retrograde mineral assemblages, providing an opportunity to evaluate controls on mineral assemblages in metabasites that experienced the same P–T conditions. Fine-grained metabasalts are garnet-bearing lawsonite
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Tectonothermal evolution of a collisional orogen in the Khammam region, southeastern India: insights from structures, phase equilibria modeling and U – Th–(total) Pb monazite geochronology Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-11-11 H. Hrushikesh, Praveen C. Singh, N. Prabhakar, Sachin K. Thakur, Bidisha Dey
The Khammam Schist Belt (KSB), southeastern India, represents a part of the collision zone that is sandwiched between the Eastern Dharwar Craton to the west and the Eastern Ghats Mobile Belt (EGMB) to the east. Quartzofeldspathic gneisses of the EGMB and garnet–kyanite metapelites of the KSB have been investigated to characterize P–T–t evolution of the Khammam region. Pseudosection modeling reveals
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Experiments on phosphate–silicate liquid immiscibility with potential links to iron oxide apatite and nelsonite deposits Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-11-08 Haroldo L. Lledo, H. Richard Naslund, David M. Jenkins
The formation of phosphorus–iron oxide (P–Fe) immiscible melts and their possible connection to the genesis of Kiruna-type and Nelsonite deposits was experimentally investigated by adding phosphoric acid (H3PO4), water, and sulfur, to andesite at 100–450 MPa, 500–900 °C, at the NiNiO and magnetite-hematite fO2 buffers using internally heated gas vessels. The addition of up to 8.02 wt% of H3PO4 to the
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Reassessing zircon-monazite thermometry with thermodynamic modelling: insights from the Georgetown igneous complex, NE Australia Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-11-05 S. Volante, W. J. Collins, E. Blereau, A. Pourteau, C. Spencer, N. J. Evans, V. Barrote, A. R. Nordsvan, Z.-X. Li, J. Li
Accessory mineral thermometry and thermodynamic modelling are fundamental tools for constraining petrogenetic models of granite magmatism. U–Pb geochronology on zircon and monazite from S-type granites emplaced within a semi-continuous, whole-crust section in the Georgetown Inlier (GTI), NE Australia, indicates synchronous crystallisation at 1550 Ma. Zircon saturation temperature (Tzr) and titanium-in-zircon
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Crustal reworking and hydration: insights from element zoning and oxygen isotopes of garnet in high-pressure rocks (Sesia Zone, Western Alps) Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-30 Vho Alice, Rubatto Daniela, Lanari Pierre, Giuntoli Francesco, Regis Daniele, Hermann Jörg
Subduction zones represent one of the most critical settings for fluid recycling as a consequence of dehydration of the subducting lithosphere. A better understanding of fluid flows within and out of the subducting slab is fundamental to unravel the role of fluids during burial. In this study, major and trace element geochemistry combined with oxygen isotopes were used to investigate metasediments
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Redox state determination of eclogite xenoliths from Udachnaya kimberlite pipe (Siberian craton), with some implications for the graphite/diamond formation Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-28 D. S. Mikhailenko, V. Stagno, A. V. Korsakov, G. B. Andreozzi, G. Marras, V. Cerantola, E. V. Malygina
The formation of diamonds within eclogitic rocks has been widely linked to the fate of carbon during subduction and, therefore, referred to conditions of pressure, temperature, and oxygen fugacity (fo2). Mantle-derived eclogite xenoliths from Udachnaya kimberlite pipes represent a unique window to investigate the formation of carbon-free, graphite–diamond-bearing and diamond-bearing rocks from the
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From static alteration to mylonitization: a nano- to micrometric study of chloritization in granitoids with implications for equilibrium and percolation length scales Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-28 Laura Airaghi, Benoit Dubacq, Anne Verlaguet, Franck Bourdelle, Nicolas Bellahsen, Alexandre Gloter
Strain accommodation in upper crustal rocks is often accompanied by fluid-mediated crystallization of phyllosilicates, which influence rock strength and shear zone formation. The composition of these phyllosilicates is frequently used for pressure–temperature–time constraints of deformation events, although it is often highly heterogeneous, even in mylonites. This study investigates the reactions producing
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Diamond-forming HDFs tracking episodic mantle metasomatism beneath Nyurbinskaya kimberlite pipe (Siberian craton) Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-26 Dmitry A. Zedgenizov, Sergei Yu. Skuzovatov, William L. Griffin, Bogdan S. Pomazansky, Alexey L. Ragozin, Viktoria V. Kalinina
We present a new dataset on the composition of high-density fluids (HDFs) in cloudy (n = 25), coated (n = 10) and cuboid (n = 10) diamonds from the Nyurbinskaya kimberlite pipe. These diamonds represent different populations each showing distinct growth histories. The cores of coated diamonds display multiple growth stages and contrasting sources of carbon. Fibrous coats and cuboid diamonds have similar
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Effect of redox on Fe–Mg–Mn exchange between olivine and melt and an oxybarometer for basalts Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-15 Jon Blundy, Elena Melekhova, Luca Ziberna, Madeleine C. S. Humphreys, Valerio Cerantola, Richard A. Brooker, Catherine A. McCammon, Michel Pichavant, Peter Ulmer
The Fe–Mg exchange coefficient between olivine (ol) and melt (m), defined as \({\text{Kd}}_{{{\text{Fe}}^{T} {-} {\text{Mg}}}}\) = (Feol/Fem)·(Mgm/Mgol), with all FeT expressed as Fe2+, is one of the most widely used parameters in petrology. We explore the effect of redox conditions on \({\text{Kd}}_{{{\text{Fe}}^{T} {-} {\text{Mg}}}}\) using experimental, olivine-saturated basaltic glasses with variable
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Diagnosing open-system magmatic processes using the Magma Chamber Simulator (MCS): part I—major elements and phase equilibria Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-15 Wendy A. Bohrson, Frank J. Spera, Jussi S. Heinonen, Guy A. Brown, Melissa A. Scruggs, Jenna V. Adams, Marie K. Takach, Garrett Zeff, Einari Suikkanen
The Magma Chamber Simulator (MCS) is a thermodynamic tool for modeling the evolution of magmatic systems that are open with respect to assimilation of partial melts or stoped blocks, magma recharge + mixing, and fractional crystallization. MCS is available for both PC and Mac. In the MCS, the thermal, mass, and compositional evolution of a multicomponent–multiphase composite system of resident magma
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Diagnosing open-system magmatic processes using the Magma Chamber Simulator (MCS): part II—trace elements and isotopes Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-15 Jussi S. Heinonen, Wendy A. Bohrson, Frank J. Spera, Guy A. Brown, Melissa A. Scruggs, Jenna V. Adams
The Magma Chamber Simulator (MCS) is a thermodynamic model that computes the phase, thermal, and compositional evolution of a multiphase–multicomponent system of a Fractionally Crystallizing resident body of magma (i.e., melt ± solids ± fluid), linked wallrock that may either be assimilated as Anatectic melts or wholesale as Stoped blocks, and multiple Recharge reservoirs (RnASnFC system, where n is
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Open-system fractional melting of Archean basalts: implications for tonalite–trondhjemite–granodiorite (TTG) magma genesis Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-12 Guangyu Huang, Richard Palin, Dan Wang, Jinghui Guo
Tonalite–trondhjemite–granodiorite (TTG) gneiss forms a major component of Archean continental crust. Resolving the origin of TTG gneisses and the secular change in their compositions is critical for better understanding how the continental crust has evolved and when a global plate tectonic regime began on Earth. Archean TTGs were generated by partial melting of hydrous basalts, although the geodynamic
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Correction to: Rheology of melts from the Colli Albani Volcanic District (Italy): a case study Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-10 Christin Kleest, Sharon L. Webb, Sara Fanara
In the published online version of the paper, the title is.
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The role of crustal contamination in the petrogenesis of nepheline syenite to granite magmas in the Ditrău Complex, Romania: evidence from O-, Nd-, Sr- and Pb-isotopes Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-10 Ágnes Ódri, Chris Harris, Petrus Le Roux
The Ditrău Complex of the Carpathian Mountains in Romania is a Mesozoic igneous complex (~ 200–230 Ma) generated in a continental rift environment. Felsic rocks of the Ditrău Complex consist of nepheline syenite, syenite, quartz syenite, quartz monzonite, monzonite and granite. The Ditrău rocks have mantle-like ɛNd values that range from + 0.8 to + 5.5 ‰. High-temperature equilibrium O-isotope fractionations
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Experimental evidence for decompression melting of metasomatized mantle beneath Colima Graben, Mexico Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-10 Eduardo Becerra-Torres, Elena Melekhova, Jon D. Blundy, Richard A. Brooker
Primitive subduction zone magmas provide information about the composition and thermal structure of the underlying mantle wedge. In the Colima Graben, Mexico, primitive lavas erupted from cinder cones range from high magnesium calc-alkaline basalts to high-K trachybasalts. This chemical diversity suggests that the sub-arc mantle wedge from which they derive is heterogeneous. To explore the conditions
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Subduction related population of diamonds in Yakutian placers, northeastern Siberian platform Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-09 A. L. Zemnukhov, V. N. Reutsky, D. A. Zedgenizov, A. L. Ragozin, R. Y. Zhelonkin, V. V. Kalinina
The 35 paired diamond intergrowths of rounded colorless transparent and gray opaque crystals from the placers of northeastern Siberian Platform were investigated. Mineral inclusions (KFsp, Coe, E-Grt, Po) detected in studied samples belong to eclogitic paragenesis. The majority of studied samples have uniform ranges of nitrogen content (1126–1982 at. ppm) and carbon isotope composition (− 16.8 to − 23
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Four-dimensional thermal evolution of the East African Orogen: accessory phase petrochronology of crustal profiles through the Tanzanian Craton and Mozambique Belt, northeastern Tanzania Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-10-09 Francisco E. Apen, Roberta L. Rudnick, John M. Cottle, Andrew R. C. Kylander-Clark, Madalyn S. Blondes, Philip M. Piccoli, Gareth Seward
U–Pb petrochronology of deep crustal xenoliths and outcrops across northeastern Tanzania track the thermal evolution of the Mozambique Belt and Tanzanian Craton following the Neoproterozoic East African Orogeny (EAO) and subsequent Neogene rifting. At the craton margin, the upper–middle crust record thermal quiescence since the Archean (2.8–2.5 Ga zircon, rutile, and apatite in granite and amphibolite
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Anatomy of a Recharge Magma: Hornblende Dacite Pumice from the rhyolitic Tshirege Member of the Bandelier Tuff, Valles Caldera, New Mexico, USA Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-09-26 Joseph R. Boro, John A. Wolff, Owen K. Neill
The 1.26 Ma Tshirege Member of the Bandelier Tuff is the second of two major (~ 400 km3, dense rock equivalent) compositionally zoned rhyolitic eruptions from the Valles caldera. Here we analyze 25 samples of a minor component of compositionally and texturally variable silicic dacite pumice (~ 67 to 72% SiO2) that is widely distributed through the unit. The dacite has a phenocryst assemblage dominated
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Crystallographic and shape orientations of magnetite micro-inclusions in plagioclase Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-09-23 Olga Ageeva, Ge Bian, Gerlinde Habler, Alexey Pertsev, Rainer Abart
Plagioclase hosted, oriented magnetite micro-inclusions are a frequently observed phenomenon in magmatic and metamorphic rocks. Understanding the orientation relationships between these inclusions and the plagioclase host is highly relevant for interpreting paleomagnetic measurements. The systematics of the shape and crystallographic orientation relationships between needle- and lath-shaped magnetite
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The intrinsic nature of antigorite breakdown at 3 GPa: Experimental constraints on redox conditions of serpentinite dehydration in subduction zones Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-09-17 Juliette Maurice, Nathalie Bolfan-Casanova, Sylvie Demouchy, Paul Chauvigne, Federica Schiavi, Baptiste Debret
Antigorite is considered as the most important source of water in subduction zones, playing a key role during arc magma genesis. Although, these magmas seem more oxidized than mid-oceanic ridge basalts (MORB), the possible inherent link between the oxidation state of arc magmas and serpentinite-derived hydrous fluids is still not well established. Here, we have performed dehydration experiments of
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The stability and composition of sulfate melts in arc magmas Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-09-14 Michael C. Hutchinson, Richard A. Brooker, John H. Dilles, Jon Blundy
The stability field and composition of immiscible sulfate melts in equilibrium with silicate magmas has been determined using experiments over a range of crustal pressures, allowing an assessment of their possible role in transporting sulfur into the sub-volcanic arc and porphyry copper deposit systems. Experimental starting materials were based on natural trachyandesite and trachydacite compositions
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Evidence for dendritic crystallization of forsterite olivine during contact metamorphism of siliceous dolostones, Alta stock aureole, Utah Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-09-14 Carl J. Beno, John R. Bowman, Patrick C. Loury, Lorraine M. Tapanila, Diego P. Fernandez
Forsterite crystals produced during metamorphism of siliceous dolomites in the Alta, Utah contact aureole were investigated in-situ and with crystal separates to constrain their aureole-scale textural and morphological variability. As the contact is approached, forsterite crystals increase in abundance but decrease in average size, suggesting greater kinetic influence on forsterite nucleation and growth
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Serpentinization of New Caledonia peridotites: from depth to (sub-)surface Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-09-02 Marc Ulrich, Manuel Muñoz, Philippe Boulvais, Michel Cathelineau, Dominique Cluzel, Stéphane Guillot, Christian Picard
Serpentinization processes occur at geological settings notably during oceanic subduction and obduction, where mantle rocks interact with water. Different types of serpentine minerals form according to temperature and pressure conditions, and potentially chemical exchanges. Therefore, the characterization of serpentine minerals, and the possible occurrence of multiple serpentine generations in mantle
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Lateral variations in the Unit 7–8 boundary zone of the Rum Eastern Layered Intrusion, NW Scotland: implications for the origin and timing of Cr-spinel seam formation Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-09-02 Felix E. D. Kaufmann, Brian O’Driscoll, Lutz Hecht
The Rum Layered Suite, NW Scotland, hosts Cr-spinel seams at the bases of peridotite–troctolite macro-rhythmic units in the eastern portion of the intrusion. Here, we present detailed field observations together with microstructural and mineral chemical analyses for the Unit 7–8 Cr-spinel seam and associated cumulates in the Eastern Layered Intrusion. Detailed mapping and sampling reveal significant
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The petrogenesis of back-arc magmas, constrained by zircon O and Hf isotopes, in the Frontal Cordillera and Precordillera, Argentina Contrib. Mineral. Petrol. (IF 3.14) Pub Date : 2020-08-29 Gregory H. Poole, Anthony I. S. Kemp, Steffen G. Hagemann, Marco L. Fiorentini, Heejin Jeon, Ian S. Williams, Eduardo O. Zappettini, Nora A. Rubinstein
The Andean margin of the South American continent has been magmatically and tectonically active for over 330 million years. It is the type location where “Cordilleran-type” magmatism and orogenesis are manifest. In Argentina and Chile, between the latitudes of 28° and 40° S, magmatism related to the Gondwanan “Cordilleran-type” orogeny is reflected in a series of Carboniferous to Triassic intrusions