Insights on arc magmatic systems drawn from natural melt …
Compositions of melt inclusions are consistent with experimental melts and reflect crystallization of a basaltic parent magma at high P H2O. In contrast, the whole rock …
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Magmatic enclaves and magma mingling/mixing
This is because magma mixing commonly occurs between magmas with fairly similar compositions or at depth in the crust during magma ascent, allowing most molten magmas to mix and homogenize. However, there are several, documented cases in which magma mingling/mixing is incomplete, resulting in the formation of magmatic enclaves that are visible ...
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Magma mixing and the origin of stratiform ore zones in the …
Magma mixing and the origin of stratiform ore zones in the Bushveld and Stillwater Complexes Other title Mélange de magma et origine des zones à minéralisation stratiforme oxydée dans les complexes du Bushveld et de Stillwater (fr) Author IRVINE, T.N; SHARPE, M.R Carnegie inst ...
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Open-system dynamics and mixing in magma mushes
At the start of the simulation, new, crystal-free magma is intruded as a dyke at the bottom of the resident mush. The evolution of the subsequent mixing between the resident mush and the new magma by penetrative convection and granular interactions is described and quantified in Fig. 1, and a computer simulation is archived inSupplementary file V1.
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Magma mixing and magmatic-to-hydrothermal fluid …
We present coupled textural, elemental, and boron isotopic data of tourmaline from the large Zhunuo-Beimulang collision-related porphyry copper deposits (PCDs) located within the western Gangdese, Tibet. Based on morphology and high-resolution mapping, the tourmaline is classified into three paragenetic generations. The first generation of schorlitic Tur-1 occurs in the …
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What is Magma Mixing?
In 1851, the chemist Bunsen published a work suggesting that mixing of magmas might originate most of the compositional variability observed in igneous rocks.Several petrologists criticized ferociously this work and the magma mixing idea was rejected for almost one century (see e.g. Wilcox 1999 for a historical overview). The rise of fractional crystallization …
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Magma mixing as a source for Pinatubo sulphur | Nature
Access through your institution. Change institution. Buy or subscribe. Subscribe to this journal. ... Snyder, D. & Tait, S. Magma mixing by convective entrainment. Nature 379, 529–531 (1996).
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Alkali Suite Anorthosites and Norites: Flotation Cumulates …
Alkali Suite Anorthosites and Norites: Flotation Cumulates from Pristine KREEP with Magma Mixing and the Assimilation of Older Anorthosite
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Magma mixing, fractional crystallization and volatile degassing during
The 1883 magma chamber was compositionally and thermally zoned with an upper portion of homogenous rhyodacite at a temperature of 880-890 °C overlying more mafic dacite at 890-913 °C, and andesite at 980-1000 °C. Mafic dacite represents a hybrid magma formed by mixing small amounts of andesite with larger amounts of evolved rhyodacite.
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Magma mixing in the genesis of the Kalatongke dioritic …
The dioritic suite formed from a mixed magma of an evolved mantle-derived basaltic magma by partial melting of subduction-modified mantle source in response to slab breakoff and a crustal-derived granitic magma at ~ 308 Ma. Before mixing with granitic magmas, basaltic magmas underwent fractional crystallization of olivine to form ferrodiorite.
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Degassing and magma mixing during the eruption of
Try logging in through your library or institution to get access to these tools. Find your institution now. Preview Available; ... Degassing and magma mixing during the eruption of Surtsey Volcano (Iceland, 1963-1967): the signatures of a dynamic and discrete rift propagation event.
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Decrypting Magma Mixing in Igneous Systems
This chapter is intended to give an overview on the fundamental concepts behind the processes of magma mixing, broadly considering interactions between different magmas.
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Magma mixing in the subvolcanic environment: petrology of the …
The mechanisms by which felsic and mafic magmas interact and approach a uniform hybrid composition through the processes of mingling and mixing have been studied in a high-level subvolcanic setting in the Spanish Hercynian at Gerena, near Seville. The compositions involved are calc-alkaline and the situation is one of tonalite-quartz diorite synplutonic dykes injected …
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Magma Mixing: History and Dynamics of an Eruption Trigger
Detailed images of the mixing features present at Grizzly Lake (Yellowstone) (a, b) and Soufrière Hills volcano (Montserrat) (c, d).Figure 1a shows the rhyolitic magma (white) has apparently intruded into the basaltic magma and the hybrid portions are present at the contact between the two end-members. Two large basaltic enclaves are visible at the bottom left and …
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Magma mixing: petrological process and volcanological tool
Magma mixing can help volcanologists "see" into the rather stagnant sub- surface reservoirs of melt. During magma mixing, magmas from different envi- ronments interact and …
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Magma mixing and crust-mantle interaction in the Triassic …
Mafic microgranular enclaves (MMEs) are common in the monzogranites from the Yangba pluton in the Bikou Terrane of central China. Zircon LA-ICP-MS U-Pb dating yields ages of 208.7 ± 0.7 Ma and 209.3 ± 0.9 Ma for the host monzogranites, and 211.9 ± 0.8 Ma for the MMEs, indicating formation from coeval magmas. The field occurrence and textures including spheroidal shapes, …
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Water transfer during magma mixing events: Insights into …
Many plutons preserve evidence of magma mixing between hydrous mafic magmas and resident felsic crystal-rich mushes. To investigate water transfer processes in such systems following thermal equilibration, we conducted 24 h experiments to establish the petrological evolution of a water-undersaturated (4 wt% H 2 O in the interstitial melt) quartz-bearing dacite …
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Tracing magma mixing in granite genesis: in situ U-Pb …
In situ zircon U-Pb and Hf-isotopic data have been determined for mafic microgranular enclaves and host granitoids from the Early Cretaceous Gudaoling batholith in the Liaodong Peninsula, NE China, in order to constrain the sources and petrogenesis of granites. The zircon U-Pb age of the enclaves (120 ± 1 Ma) is identical to that of the host monzogranite (120 ± 1 Ma), establishing …
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Magma Mixing in Igneous Systems
Since the first hypothesis, evidences of magma mixing processes have been accumulated in the literature allowing this natural phaenomenon to be defined as fundamental petrological processes playing a role in activating volcanic eruptions and generating compositional variability in igneous systems. Here, we review the key concepts to provide the best understanding of the physical …
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Magmatic Ore Deposits | SpringerLink
Irvine, T. N. (1986) Magma mixing and the origin of the stratiform oxide zones in the Bushveld and Stillwater complexes, in B. Carter (ed), Metallogeny of basic and ultrabasic rocks, Institute of Mining and Metallurgy, ... Western Australia, Institution of Mining and Metallurgy, London, ...
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Magma mixing and forced exsolution of CO 2 during the …
Oldoinyo Lengai is probably most famous for being the only active volcano on Earth which is erupting natrocarbonatitic magma. However, the mildly explosive natrocarbonatitic activity is alternating with highly explosive, nephelinitic eruptions of which the most recent episode occurred in September 2007 (and lasted until April 2008).
Here we present petrographic …اقرأ أكثر
Origin of Minette by Mixing of Lamproite and Dacite …
The magma-mixing model explains the reverse zoning and resorption features of phlogopite macrocrysts commonly recognized in calcalkaline lamprophyres elsewhere. Therefore, this mixing mechanism may be globally applicable for the origin of minettes associated with calcalkaline granitic plutonism in post-orogenic settings.
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Magma Mixing and the Production of Compositional …
Magma mixing or mingling is a popular hypothesis, generally proposed in terms of blending between a crustal melt and mafic material from the mantle that caused that melting.
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Magma mixing: a mechanism for triggering acid explosive eruptions
The 1875 plinian eruption of Askja, Iceland is an example of an explosive eruption triggered by magma mixing. ... Access through your institution. Change institution. Buy or subscribe.
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The roles of partial melting of metasomatised mantle, magma mixing …
Polytope Vector Analysis allowed an integrated quantitative characterization of magma differentiation, including magma mixing and subsequent fractional crystallization. The identification of mixing and fractionation processes in calc-alkaline minettes genesis, which otherwise does not show spatial and temporal association in the field with ...
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Dynamic mixing in magma bodies: Theory, simulations, and …
The mixing time (t mix) is defined as the time required for the intensity of segregation to decay to a certain value. Magma mixing occurs by complex time-dependent flows with numerous flow reversals associated with local unmixing events superimposed on a larger time scale process in which the intensity of segregation decays to zero.
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Open-system dynamics and mixing in magma mushes
Here we use a discrete-element numerical model that resolves crystal-scale granular interactions and fluid flow, to simulate the open-system dynamics of a magma mush.
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(PDF) Mineralogical Constraints on the Magma …
We show that magma mixing plays a significant role in the origins of diverse volcanism in the middle Okinawa Trough; more specifically, two of the three types of andesites (types B and C) and one ...
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The importance of fractional crystallization and
Contrib Mineral Petrol (2011) 162:573597. DOI 10.1007/s00410-011-0613-8. ORIGINAL PAPER. The importance of fractional crystallization and magma mixing in controlling chemical differentiation at Sphan stratovolcano, eastern Anatolia, Turkey
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Magma Mixing and Crustal Recycling Recorded in Ternary …
About 25–30% of the feldspar phenocrysts contain evidence for magma mixing in the form of (1) partial to severe dissolution–resorption rims, (2) distinct zones of drastically different compositions and (3) overgrowth textures on formerly resorbed crystals. ... If you are a member of an institution with an active account, you may be able to ...
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