DOCSLIB.ORG

MELT INCLUSION RECORD of MAGMATIC IMMISCIBILITY in CRUSTAL and MANTLE MAGMAS Vadim S. Kamenetsky School of Earth

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
MELT INCLUSION RECORD of MAGMATIC IMMISCIBILITY in CRUSTAL and MANTLE MAGMAS Vadim S. Kamenetsky School of Earth CHAPTER 4: MELT INCLUSION RECORD OF MAGMATIC IMMISCIBILITY IN CRUSTAL AND MANTLE MAGMAS Vadim S. Kamenetsky School of Earth Sciences and ARC Centre of Excellence in Ore Deposits, University of Tasmania, Private Bag 79, Hobart, Tasmania 7001, Australia E-mail: [email protected] INTRODUCTION process. If separation of immiscible phases was Immiscibility (unmixing of melts and fluids) efficient, the residual magma should be significantly should be almost inevitable at some point in the depleted in incompatible volatiles and metals evolution of most mantle and crustal magmas relative to the parental magma, and reconstructing during cooling and crystallization. Formation of two the original metal and volatile content is extremely immiscible phases “results in a major geochemical difficult. One rapidly developing approach to this fractionation – all chemical species present, the problem is the use of melt and fluid inclusions elements (and their isotopes), and their various trapped and preserved in magmatic minerals (e.g., compounds, become distributed between these two Roedder 1992, De Vivo & Frezzotti 1994, Bodnar phases…the compositional divergence between the 1995, Lowenstern 1995, Student & Bodnar 1999, two phases is…extreme” (Roedder 2003). The Frezzotti 2001, Kamenetsky et al. 2003, variations in compositions of melts undergoing Lowenstern 2003 and references therein). Such immiscibility, and physical parameters of their inclusions provide the closest approximation to evolution in the plutonic environments, mean that samples of continuously evolving (and thus each intrusion should be expected to show ephemeral) melts and magmatic fluids. Many differences in the processes of exsolution and studies of magmatic inclusions have made possible compositions of exsolving phases. One of the the recognition of several types of magmatic immiscible phases is universally volatile-rich, and immiscibility (e.g., between silicate melts, sulfide this has important consequences for further magma melts, aqueous and carbonic liquids and vapors, evolution and geological processes related to it. hydrosaline liquids and various combinations of More specifically, volatile-rich phases generally these). For brevity, in this work only those have significant density and viscosity contrasts with examples from plutonic systems of which the author parental silicate magmas, and thus rapid separation has first-hand experience will be presented and of the newly exsolved phases is expected. Further, discussed in detail. the exsolution of volatile-rich phases exerts major controls on the chemistry of a magmatic system, TYPES OF MAGMATIC IMMISCIBILITY particularly on metal partitioning between Immiscible silicate melts immiscible melts and fluids, so the volatile phase is Among the reports on silicate-silicate melt highly efficient at sequestering the metals (e.g., immiscibility (e.g., Roedder & Weiblen 1970, De Candela 1989, Candela & Piccoli 1995, Williams et 1974, Dixon & Rutherford 1979, McBirney 1980, al. 1995, Heinrich et al. 1999, Webster 2004). Philpotts 1982, Jakobsen et al. 2005) only a few are Magmatic immiscibility and the related formation of related to mineralized magmatic systems (e.g., volatile-rich melts and fluids are prerequisites for pegmatites of the Ehrenfriedersdorf Sn–W deposit, the origin of mineralized hydrothermal solutions Germany, Thomas et al. 2000, the La Copa felsic that may transport metals to a suitable depositional intrusions within the Rio Blanco Cu–Mo deposit, site. Immiscible separation, however, is not Chile, Davidson & Kamenetsky 2001, Davidson et restricted to magmas that form mineralized rocks. al. 2005). The fugitive nature of magmatic immiscibility Quartz-hosted silicate melt inclusions from involves problems in unraveling physical and the La Copa complex, coexisting within the same chemical characteristics of this fundamental grains and growth planes, belong to two contrasting Mineralogical Association of Canada Short Course 36, Montreal, Quebec, p. 1-xx 81 V.S. KAMENETSKY types: clear rhyolitic glass with one or several mapping, is elevated metal (Fe, Mn, Cu, Zn, Pb) shrinkage bubbles, and dark fine-grained crystalline and alkali element abundances in a volatile-rich aggregates of feldspar, mica and quartz (Fig. 4-1, silicate melt (Fig. 4-2). Davidson & Kamenetsky 2001, Davidson et al. Davidson & Kamenetsky (2001) 2005). Dark inclusions may also contain daughter emphasized that dark silicate melt inclusions, crystals of sphalerite, chalcopyrite, Fe oxides and enriched in volatiles and metals, are important to hydroxides, halite, carbonates and unidentified the understanding of late-stage magmatic phases. They are also characterized by a significant immiscibility and suggested revisiting the results of and variable amount of fluid components, identified other studies on similar inclusions. For example, the by laser Raman spectroscopy as vapor and liquid melt inclusions from the Lower Bandelier Tuff H2O. A common feature of dark inclusions is an (Dunbar & Hervig 1992) can be “strongly associated halo of aqueous vapor-dominated devitrified” and “darker in color…and some contain bubbles (< 5 µm) forming a discontinuous rim, clots of crystals”, and also contain up to 8 wt.% which probably formed as a result of post- H2O, in contrast to clear glass inclusions (3–5 wt.% crystallization decrepitation of inclusions. H2O). It is possible that crystallization of trapped Decrepitation of seemingly intact large dark melts was promoted by high H2O abundances. The inclusions at T~600°C is responsible for their interpretation of coexisting volatile-poor, and failure to melt and homogenize during heating volatile-rich, silicate melts (melt inclusions) as experiments. Some smaller inclusions show melting immiscible liquids at La Copa (Davidson & at 750–800°C, although complete homogenization Kamenetsky 2001) was partly based on the phase (bubble disappearance) was not achieved even at diagram derived from homogenization experiments higher temperatures. with melt inclusions from the Ehrenfriedersdorf Clear evidence of silicate-silicate melt pegmatite (Thomas et al. 2000). According to their immiscibility in the La Copa samples is observed in ground-breaking study, the original H2O- inclusions that comprise both clear glass and undersaturated felsic magma separates at a certain rounded, commonly spherical, crystalline and temperature into two immiscible liquids, a volatile- amorphous dark masses of dominantly silicate poor silicate melt and a volatile-rich silicate melt (or phases with interstitial aqueous fluid (Fig. 4-2). The a silicate-bearing fluid). The latter inevitably relative proportions of trapped immiscible melts in evolves via one or more consecutive unmixing such composite inclusions are highly variable, and events into aqueous metal-, salt-rich their compositions are distinctly different (Fig. 4-2). (“hydrothermal”) fluids with a potential for The main difference, as indicated by PIXE economic mineralization (see below). FIG. 4-1. A growth plane in a quartz phenocryst from La Copa complex, Chile (Davidson & Kamenetsky 2006), containing coexisting crystallized silicate melt inclusion (1), glass inclusions (2) and two-phase aqueous fluid inclusions (3). The two- phase aqueous inclusions show Brownian motion of the vapor bubbles, and freeze at low temperature. 82 MELT INCLUSION RECORD OF MAGMATIC IMMISCIBILITY IN CRUSTAL AND MANTLE MAGMAS FIG. 4-2. Optical images and proton-induced X-ray emission (PIXE) element maps of quartz-hosted composite inclusions from La Copa complex, Chile (Davidson et al. 2005). The inclusions are composed of clear silicate glass and a globule of crystallized volatile-rich melt (dark). Outlines on element maps mark boundaries of inclusions and their volatile-rich silicate globules. Scale bars are 15 µm. Immiscible silicate melt and aqueous saline fluids trapped in the same growth plane, is provided in Quartz phenocrysts in felsic intrusive rocks Fig. 4-1 (after Davidson & Kamenetsky 2006). commonly contain numerous aqueous fluid Notably, the dark silicate melt inclusion in Fig. 4-1 inclusions, but in most cases they are clearly later belongs to the volatile-rich type described above. than the silicate melt inclusions (if present) in the Another example of explicit immiscibility between same grains. Trails of secondary aqueous inclusions the silicate melt and magmatic aqueous fluid prior commonly obliterate any evidence of primary to or simultaneous with quartz crystallization is aqueous inclusions, at least presenting a recorded by Davidson & Kamenetsky (2006) as considerable challenge to their confident composite inclusions containing very large numbers identification. An unambiguous example of silicate of one- or two-phase aqueous bubbles in a silicate melt and aqueous two-phase fluid inclusions, co- glass (microemulsion, Fig. 4-3). 83 V.S. KAMENETSKY FIG. 4-3. Optical images and proton-induced X-ray emission (PIXE) element maps of quartz-hosted composite inclusions from La Copa complex, Chile (Davidson et al. 2005). The inclusions are composed of clear silicate glass and numerous bubbles of aqueous fluid (vapor- and liquid-rich). Outlines on element maps mark boundaries of inclusions and aqueous bubbles (on B). Scale bars are 25 µm. On the other hand, in cases where post-entrapment exsolution of the aqueous fluid. crystallization occurs deeper than the magma Partly crystallized silicate melt inclusions saturation in H2O, primary aqueous fluid inclusions from both localities are
Load more

Recommended publications
  • Bursting the Bubble of Melt Inclusions†K
    American Mineralogist, Volume 100, pages 672–673, 2015 HIGHLIGHTS AND BREAKTHROUGHS Bursting the bubble of melt inclusions†k JACOB B. LOWENSTERN1,* 1U.S. Geological Survey, Volcano Science Center, Menlo Park, California 94025, U.S.A. Abstract: Most silicate melt inclusions (MI) con- crystal and trapped liquid create conditions that strongly favor tain bubbles, whose significance has been alternately creation of a low-density phase. In studies of FI, the bubbles are calculated, pondered, and ignored, but rarely if ever studied intensively (Samson et al. 2003). Experimental heating directly explored. Moore et al. (2015) analyze the and homogenization provide insight into the temperature of en- bubbles, as well as their host glasses, and conclude trapment and the conditions of formation. Raman spectroscopy and other techniques can provide quantitative information on that they often hold the preponderance of CO2 in gas species within bubbles. the MI. Their findings entreat future researchers Surprisingly, little has been done to analyze the bubbles within to account for the presence of bubbles in MI when MI—perhaps partly because of interference from the surround- calculating volatile budgets, saturation pressures, ing glass greatly complicates spectroscopic and other analytical and eruptive flux. Keywords: Melt inclusion, glass methods. Many authors recognize that bubbles can contain a inclusion, bubble, volatile, CO2 significant percentage of the volatiles in an inclusion, particularly for those with low solubility in the melt such as CO2 (Anderson On page 806, of this issue, Lowell Moore and colleagues and Brown 1993). But there is little consensus on how to account contribute an exciting, scholarly, and admirably thorough trea- for the presence of bubbles.
    [Show full text]
  • Mineral Processing
    Mineral Processing Foundations of theory and practice of minerallurgy 1st English edition JAN DRZYMALA, C. Eng., Ph.D., D.Sc. Member of the Polish Mineral Processing Society Wroclaw University of Technology 2007 Translation: J. Drzymala, A. Swatek Reviewer: A. Luszczkiewicz Published as supplied by the author ©Copyright by Jan Drzymala, Wroclaw 2007 Computer typesetting: Danuta Szyszka Cover design: Danuta Szyszka Cover photo: Sebastian Bożek Oficyna Wydawnicza Politechniki Wrocławskiej Wybrzeze Wyspianskiego 27 50-370 Wroclaw Any part of this publication can be used in any form by any means provided that the usage is acknowledged by the citation: Drzymala, J., Mineral Processing, Foundations of theory and practice of minerallurgy, Oficyna Wydawnicza PWr., 2007, www.ig.pwr.wroc.pl/minproc ISBN 978-83-7493-362-9 Contents Introduction ....................................................................................................................9 Part I Introduction to mineral processing .....................................................................13 1. From the Big Bang to mineral processing................................................................14 1.1. The formation of matter ...................................................................................14 1.2. Elementary particles.........................................................................................16 1.3. Molecules .........................................................................................................18 1.4. Solids................................................................................................................19
    [Show full text]
  • Understanding a Volcano Through a Droplet: a Melt Inclusion Approach
    Journal of Geochemical Exploration 171 (2016) 4–19 Contents lists available at ScienceDirect Journal of Geochemical Exploration journal homepage: www.elsevier.com/locate/jgeoexp Understanding a volcano through a droplet: A melt inclusion approach C. Cannatelli a,b,⁎,A.L.Dohertya, R. Esposito c,A.Limaa, B. De Vivo a a Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università di Napoli Federico II, Italy b Department of Geology and Andean Geothermal Centre of Excellence (CEGA), Universidad de Chile, Plaza Ercilla 803, Santiago, Chile c Earth, Planetary and Space Sciences, UC Los Angeles, CA, USA article info abstract Article history: This review paper is intended to be a guideline to novices on how to conduct research on silicate melt inclusions Received 29 January 2015 in volcanic environments, which analytical techniques are more suitable to gather the desired data and the major Revised 9 July 2015 pitfalls scientist may encounter. Silicate melt inclusions (SMIs) are small quantities of silicate melt that are Accepted 3 October 2015 trapped in minerals during their growth or crystallization. They contain liquids formed in equilibrium with Available online 23 October 2015 their host minerals and therefore record the liquid line of descent of magmatic systems. Upon trapping, SMIs be- come ideally closed to the surrounding environment, and behave as time capsules, giving important information Keywords: Melt inclusions about processes that originated magmas and the nature of their mantle source. A melt inclusions investigation
    [Show full text]
  • Melt Inclusions in Chassignites: a Connection Between Martian Meteorites and in Situ Evolved Rocks at Gale Crater
    51st Lunar and Planetary Science Conference (2020) 2342.pdf MELT INCLUSIONS IN CHASSIGNITES: A CONNECTION BETWEEN MARTIAN METEORITES AND IN SITU EVOLVED ROCKS AT GALE CRATER. P. Wu1, E. Gazel1, and A. Udry2 1Department of Earth and Space Sciences, Cornell University ([email protected], [email protected]); 2Department of Geoscience, UNLV ([email protected]). Introduction: UnderstandinG the compositional Methods: We used six parental magma composi- diversity of igneous rocks is the key to investigate tions calculated from NWA 2737 melt inclusions by conditions of meltinG and sources within the martian He et al. [3] as startinG compositions for the modeling. interior. Meteorites, our only martian samples, can be He et al. [3] analyzed nine melt inclusions in a sinGle analyzed with the most advanced laboratory analytical thin section of NWA 2737. Measured phase composi- techniques and thus has dominated our knowledge of tions and phase abundances are used to calculate the martian iGneous chemistry. Most martian meteorites bulk composition of inclusions [3]. are classified into three major cateGories, sherGottite, AmonG the nine melt inclusions, olivine, low-Ca nakhlite, and chassignite (SNC). As a type of olivine pyroxene, kaersutitic amphibole, augite, apatite, chro- cumulates with abundant melt inclusions, chassiGnites mite, sulfide, alkali-rich Glass, and some Ti-biotite can provide key information on the compositions of were identified [3]. Since MI-4 and MI-5 are likely parental magmas, volatile budgets, and early crystalli- off-center cuts and MI-6 includes some biotite and zation processes. Chassigny, Northwest Africa (NWA) may represent composite Grains, we excluded MI-4, 2737 and Northwest Africa (NWA) 8694 are the only MI-5, and MI-6 from our study.
    [Show full text]
  • Thirty-Fourth List of New Mineral Names
    MINERALOGICAL MAGAZINE, DECEMBER 1986, VOL. 50, PP. 741-61 Thirty-fourth list of new mineral names E. E. FEJER Department of Mineralogy, British Museum (Natural History), Cromwell Road, London SW7 5BD THE present list contains 181 entries. Of these 148 are Alacranite. V. I. Popova, V. A. Popov, A. Clark, valid species, most of which have been approved by the V. O. Polyakov, and S. E. Borisovskii, 1986. Zap. IMA Commission on New Minerals and Mineral Names, 115, 360. First found at Alacran, Pampa Larga, 17 are misspellings or erroneous transliterations, 9 are Chile by A. H. Clark in 1970 (rejected by IMA names published without IMA approval, 4 are variety because of insufficient data), then in 1980 at the names, 2 are spelling corrections, and one is a name applied to gem material. As in previous lists, contractions caldera of Uzon volcano, Kamchatka, USSR, as are used for the names of frequently cited journals and yellowish orange equant crystals up to 0.5 ram, other publications are abbreviated in italic. sometimes flattened on {100} with {100}, {111}, {ill}, and {110} faces, adamantine to greasy Abhurite. J. J. Matzko, H. T. Evans Jr., M. E. Mrose, lustre, poor {100} cleavage, brittle, H 1 Mono- and P. Aruscavage, 1985. C.M. 23, 233. At a clinic, P2/c, a 9.89(2), b 9.73(2), c 9.13(1) A, depth c.35 m, in an arm of the Red Sea, known as fl 101.84(5) ~ Z = 2; Dobs. 3.43(5), D~alr 3.43; Sharm Abhur, c.30 km north of Jiddah, Saudi reflectances and microhardness given.
    [Show full text]
  • High Pre-Eruptive Water Contents Preserved in Lunar Melt Inclusions
    REPORTS and the catalyst tolerates useful substrate func- 10. P. P. Fu, R. G. Harvey, Chem. Rev. 78, 317 (1978). 25. L. H. Heitman et al., J. Med. Chem. 52, 2036 tional groups, including aromatic and heteroatom 11. T. Moriuchi, K. Kikushima, T. Kajikawa, T. Hirao, (2009). Tetrahedron Lett. 50, 7385 (2009). 26. R. A. Sheldon, J. M. Sobczak, J. Mol. Catal. 68, substituents. With the development of improved 12.C.S.Yi,D.W.Lee,Organometallics 28, 947 1 (1991). methods for safe and scalable aerobic oxidation (2009). 27. J. E. Bercaw, N. Hazari, J. A. Labinger, J. Org. Chem. 73, reactions (30), dehydrogenation methods of this 13.P.F.Schuda,W.A.Price,J. Org. Chem. 52, 1972 8654 (2008). type could have an important impact on laboratory- (1987). 28. J. E. Bercaw, N. Hazari, J. A. Labinger, P. F. Oblad, Angew. Chem. Int. Ed. 47, 9941 (2008). and industrial-scale chemical synthesis. 14. J. Muzart, J. P. Pete, J. Mol. Catal. 15, 373 (1982). 15. T. T. Wenzel, J. Chem. Soc. Chem. Commun. 1989, 932 29. G. E. Dobereiner, R. H. Crabtree, Chem. Rev. 110,681 (1989). (2010). 30. X. Ye, M. D. Johnson, T. Diao, M. H. Yates, S. S. Stahl, References and Notes 16. J. Muzart, Eur. J. Org. Chem. 2010, 3779 (2010). Green Chem. 12, 1180 (2010). 1. J. H. P. Tyman, Synthetic and Natural Phenols (Elsevier, Acknowledgments: We are grateful to the NIH New York, 1996). 17. D. R. Buckle, in Encyclopedia of Reagents for Organic Synthesis, D. Crich, Ed. (Wiley, New York, 2010).
    [Show full text]
  • A Melt Inclusion Study on Volatile Abundances in the Lunar Mantle
    Available online at www.sciencedirect.com ScienceDirect Geochimica et Cosmochimica Acta 249 (2019) 17–41 www.elsevier.com/locate/gca A melt inclusion study on volatile abundances in the lunar mantle Peng Ni (倪鹏) a,⇑, Youxue Zhang (张有学) a, Sha Chen (陈沙) a, Joel Gagnon b a Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005, USA b Department of Earth and Environmental Sciences, University of Windsor, Windsor, Ontario N9B 3P4, Canada Received 22 December 2017; accepted in revised form 23 December 2018; Available online 08 January 2019 Abstract Earth’s Moon was thought to be highly depleted in volatiles due to its formation by a giant impact. Over the last decade, however, evidence has been found in apatites, lunar volcanic glass beads, nominally anhydrous minerals and olivine-hosted melt inclusions, to support a relatively ‘‘wet” Moon. In particular, based on H2O/Ce, F/Nd, and S/Dy ratios, recent melt inclusion (MI) work estimated volatile (H2O, F, and S) abundances in lunar rocks to be similar to or slightly lower than the terrestrial depleted mantle. Uncertainties still occur, however, in whether the limited numbers of lunar samples studied are representative of the primitive lunar mantle, and whether the high H2O/Ce ratio for pyroclastic sample 74220 is due to local heterogeneity. In this paper, we report major element, trace element, volatile, and transition metal data in MIs for 5 mare basalt samples (10020, 12040, 15016, 15647 and 74235) and a pyroclastic deposit (74220). With our new lunar MI data, H2O/Ce ratios are still found to vary significantly among different lunar samples, from 50 for 74220, to 9 for 10020, 3 for 74235, 1.7 to 0.9 for 12008, 15016, and 15647, and 0.5 for 12040.
    [Show full text]
  • Mineral-Hosted Melt Inclusions How Do We Read the Stories They Have to Tell?
    Mineral-Hosted Melt Inclusions How do we read the stories they have to tell? Woods Hole Oceanographic Institution Woods Hole, MA, USA August 10-12, 2018 Thank you to our sponsors. Mineral-Hosted Melt Inclusions, Woods Hole, MA, USA, 10-12 August 2018 Welcome to Mineral-Hosted Melt Inclusions: How do we read the stories they have to tell? Thank you to our sponsors. The study of mineral-hosted melt inclusions traces Over the next two days, fifteen invited speakers its origins all the way back to the mid-nineteenth will discuss the state of our knowledge with respect century. In 1857, Henry Clifton Sorby recognized to mineral-hosted melt inclusions. Topics range that the presence of “glass cavities” demonstrates from the origin and fidelity of mineral-hosted that the host crystals had a magmatic – rather than melt inclusions to the application of state-of-the- an aqueous – origin and used this observation to art micro-analytical techniques to quantify their argue that granite is the product of fusion rather compositions. Each talk will be followed by a than precipitation from a fluid. Today, these small discussion session intended to promote interaction pockets of silicate melt entrapped within growing among all the attendees. One objective is to mineral grains are used to study everything from develop guidelines for publication of data from melt mantle heterogeneity to pre-eruptive magmatic inclusion studies to be summarized in a collegial volatiles and the oxidation state of the upper mantle. manuscript that the organizers will submit for The information recorded in melt inclusions is publication shortly after the workshop.
    [Show full text]
  • New Insights from Olivine-Hosted Melt Inclusions from Multiple Samples
    JOURNAL OF PETROLOGY VOLUME 53 NUMBER 4 PAGE S 6 65 ^ 6 98 2012 doi:10.1093/petrology/egr075 Melting and Crustal Processes at the FAMOUS Segment (Mid-Atlantic Ridge): New Insights from Olivine-hosted Melt Inclusions from Multiple Samples MURIEL LAUBIER*, ALLISON GALE AND CHARLES H. LANGMUIR DEPARTMENT OF EARTH AND PLANETARY SCIENCES, HARVARD UNIVERSITY, 20 OXFORD STREET, CAMBRIDGE, Downloaded from MA 02138, USA RECEIVED SEPTEMBER 29, 2010; ACCEPTED DECEMBER 2, 2011 ADVANCE ACCESS PUBLICATION FEBRUARY 10, 2012 http://petrology.oxfordjournals.org/ Most published studies of olivine-hosted melt inclusions from (MREE/HREE) ratios.The high Al2O3 and low SiO2 contents, mid-ocean ridges have been based on a single sample. Here we present as well as positive Sr anomalies in some of the high-Al melt inclu- a comprehensive melt inclusion study of major and trace elements sions, are best explained by assimilation of plagioclase-bearing cu- from a single ocean ridge segment, the FAMOUS segment of the mulates. The trace element variability in the high-Mg melt Mid-Atlantic Ridge. The melt inclusion dataset includes 312 inclusions is not consistent with a simple continuous melting column olivine-hosted (Mg-number 85^92) melt inclusions from 14 samples and requires pooling of near-fractional melts within the melting distributed along the segment.This permits a more comprehensive as- regime and a variable mantle source composition. Because the mean at Harvard University on June 4, 2012 sessment of the variability within melt inclusions from a single composition of these melt inclusions reflects greater extents of melting region, and of the relationship between melt inclusion and lava com- than the lavas, we propose that the melt inclusions come from the positions.
    [Show full text]
  • 9 Microthermometry and Raman Spectroscopy Of
    Rom. J. Mineral Deposits, vol. 92 (2019), No. 1-2, p. 9-32 MICROTHERMOMETRY AND RAMAN SPECTROSCOPY OF FLUID AND MELT INCLUSIONS IN THE ALPINE PORPHYRY COPPER DEPOSITS FROM ROMANIA: INSIGHTS ON MICROMETALLOGENY Ioan PINTEA1*, Sorin Silviu UDUBAŞA2, Elena Luisa IATAN3, Ion BERBELEAC3, Daniel BÎRGĂOANU1, Oana Claudia CIOBOTEA-BARBU1, Eduard GHINESCU1 1Geological Institute of Romania, 1, Caransebeș Str., 012271 Bucharest, Romania; 2Univ. of Bucharest, 1, N. Bălcescu Blv., 010041 Bucharest, Romania; 3Institute of Geodynamics of Romanian Academy, 19-21, J.-L. Calderon Str., 020032 Bucharest, Romania. * [email protected] Abstract: The paper presents complementary analyses of Raman spectroscopy and high-temperature microthermometry on fluid/melt inclusions from alpine porphyry copper and associated epithermal and skarn deposits from Romania. It reveals a complex phase association and multistage evolution during the magmatic-to- hydrothermal processes underlying the deep-seated MASH zones of the related subduction factories. Important differences in P-T-X properties were found for the main mineralizing processes between the two porphyry copper deposit clusters, one in the Banat region of the South Carpathians (Upper Cretaceous) and other in the Metaliferi Mountains of the South Apuseni Mountains (Miocene). These differences ranged up to 300oC in temperature, more than 1-3 kbar of pressure and 20-30 wt% NaCl eq. salinity. Although the magmatic-hydrothermal transitions are characterized by melt-melt-fluid immiscibility at high P-T conditions
    [Show full text]
  • The November 2002 Eruption of Piton De La Fournaise, Réunion: Tracking the Pre-Eruptive Thermal Evolution of Magma Using Melt Inclusions
    Bull Volcanol (2009) 71:1077–1089 DOI 10.1007/s00445-009-0287-5 RESEARCH ARTICLE The November 2002 eruption of Piton de la Fournaise, Réunion: tracking the pre-eruptive thermal evolution of magma using melt inclusions Nathalie Vigouroux & A. E. Williams-Jones & Paul Wallace & Thomas Staudacher Received: 19 November 2007 /Accepted: 29 April 2009 /Published online: 6 June 2009 # Springer-Verlag 2009 Abstract The November 2002 eruption of Piton de la estimate eruption temperatures. The November 2002 melt Fournaise in the Indian Ocean was typical of the activity of inclusion compositions suggest that they were at temper- the volcano from 1999 to 2006 in terms of duration and atures between 1,070°C and 1,133°C immediately before volume of magma ejected. The first magma erupted was a eruption and quenching. This relatively wide temperature basaltic liquid with a small proportion of olivine phenocrysts range may reflect the fact that most of the melt inclusions (Fo81) that contain small numbers of melt inclusions. In were from olivine in lava samples and therefore likely subsequent flows, olivine crystals were more abundant and underwent minor but variable amounts of post-eruptive 2+ richer in Mg (Fo83–84). These crystals contain numerous melt crystallization and Fe loss by diffusion due to their and fluid inclusions, healed fractures, and dislocation relatively slow cooling on the surface. In contrast, melt features such as kink bands. The major element composition inclusions in tephra samples from past major eruptions of melt inclusions in this later olivine (Fo83–84)isoutof yielded a narrower range of higher eruption temperatures equilibrium with that of its host as a result of extensive post- (1,163–1,181°C).
    [Show full text]
  • Fluid Inclusions in Rocks
    Inclusion research: melts and fluids in rocks (geology) - SmarterSc... http://www.smarterscience.com/inclusion-research.html Fluid inclusions in rocks http://www.smarterscience.com - Phone: +44 23 9234 2909 - Bubbles in Amsterdam: melt and fluid inclusion research at the Vrije Universiteit This article was also published in The Geochemical News, the newsletter of the Geochemical Society, number 112, in July 2002. It is also online Smithsonian's Department of Mineral Science and of course at the Geochemical Society, and used as teaching text at a Danish university. Angelina Souren On March 29, 2001, the University of Liège in Belgium awarded an honorary doctorate (Docteur Honoris Causa) to Jacques Touret. On September 19, 2001, the VU organized a symposium in Jacques’s honor: "Fluids at depth" . In addition, the journal Lithos dedicated an entire issue to Jacques. Jacques Touret, having reached the Dutch retirement age, was leaving. He has bought a house in France and moved back to his home country, where his wife works as a mineralogist and curator at the Musée de Mines of the École des Mines in Paris. After the recent graduation of Bin Fu, Jacques still has one Ph.D. student left in Amsterdam (Eduardo Campos). Jacques Touret is also a member of the Royal Netherlands Academy of Sciences and as such is currently concerned with documenting the history of the earth sciences. So instead of traveling back and forth to France, he now travels back and forth to The Netherlands, where he will always be very welcome. The Dutch like Jacques, not only because of his scientific contributions but also because of his friendly nature.
    [Show full text]