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Experimental studies on the behaviour of rare earth elements and tin in granitic systems [Elektronische Ressource] / vorgelegt von Quach Duc Tin

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139 pages
Experimental studies on the behaviour of rare earth elements and tin in granitic systems DISSERTATION zur Erlangung des Doktorgrades der Naturwissenschaften der Geowissenschaflichen Fakultät der Eberhard-Karls-Universität Tübingen vorgelegt von QUACH DUC TIN aus Hanoi (Vietnam) - 2007 - Tag der mündlichen Prüfung: Dekan: Prof. Dr. Peter Grathwohl 1. Berichterstatter: Prof. Dr. Hans Keppler 2. Berichterstatter: Priv. Doz. Dr. Wolfgang Siebel iii Acknowledgements This thesis is the results of the scientific research mainly at Institute for Geosciences, University of Tuebingen (EBERHARD-KARLS-UNIVERSITÄT TÜBINGEN). Some parts were carried out at the University of Hannover and Swiss Federal Institute of Technology in Zürich (ETH Zürich). With a great sense of appreciation, I take the opportunity to thank those people who have helped, supported and encouraged me along the way. I would like to thank my colleagues and other people I had the opportunity to work with. I am greatly indebted to my supervisor, Prof. Dr. Hans Keppler, whose comments, valuable scientific discussions and critical ideas are highlights of various aspects of this research. Without his financial aid, sound guidance, supervision, motivation, kindness and continual support, this research would have not reached its present form.
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Experimental studies
on the behaviour of rare earth elements
and tin in granitic systems




DISSERTATION

zur Erlangung des Doktorgrades der Naturwissenschaften


der Geowissenschaflichen Fakultät
der Eberhard-Karls-Universität Tübingen



vorgelegt von


QUACH DUC TIN
aus Hanoi (Vietnam)








- 2007 -
























Tag der mündlichen Prüfung:
Dekan: Prof. Dr. Peter Grathwohl
1. Berichterstatter: Prof. Dr. Hans Keppler
2. Berichterstatter: Priv. Doz. Dr. Wolfgang Siebel
iii

Acknowledgements

This thesis is the results of the scientific research mainly at Institute for Geosciences,
University of Tuebingen (EBERHARD-KARLS-UNIVERSITÄT TÜBINGEN). Some parts
were carried out at the University of Hannover and Swiss Federal Institute of Technology in
Zürich (ETH Zürich). With a great sense of appreciation, I take the opportunity to thank those
people who have helped, supported and encouraged me along the way. I would like to thank
my colleagues and other people I had the opportunity to work with.

I am greatly indebted to my supervisor, Prof. Dr. Hans Keppler, whose comments, valuable
scientific discussions and critical ideas are highlights of various aspects of this research.
Without his financial aid, sound guidance, supervision, motivation, kindness and continual
support, this research would have not reached its present form. With his patience and
encouragement, he gave me the confidence to complete this thesis. I also highly appreciate his
support by sending me to other scientific institutions to do the research as well as solving the
financial matters related to the research. Moreover, his personal qualities, inter-personal skills
and good humor created an excellent working environment at Institute for Geosciences.

Most of this work was funded by the DFG Leibniz award of my supervisor, Prof. Hans
Keppler. In addition, the German Academic Exchange Service (DAAD) fellowship program
sponsored this work.

I would also like to acknowledge and extend my thanks to Dr. Andreas Audetat for his ideas
about inclusion trapping experimental set-up and for many helpful discussions and
suggestions during the course of the research. I thank him for arranging the working session
in ETH Zürich, for providing technical assistance with Laser-ablation ICP-MS and for his
patience and creativity when working with me.

My thanks and appreciation go out to all the others who helped me with scientific and
technical aspects of this project, including PD. Dr. Thomas Wenzel for teaching and
providing me technical assistance in working with electron microprobe (JEOL 8900), Dr.
Christoph Berthold for helping me to carry out X-ray diffraction analysis, Prof. Detlef
Günther and Kathrin Hametner for arranging the LA- ICP-MS analysis in ETH, Zurich, Prof.
Marcus Nowak for arranging the experiments at Hannover University and Mr. Norbert iv

Walker for his assistance in maintaining the high temperature and pressure vessels system in
the lab.

Great appreciation is given to my colleagues and friends in the Institute for Geosciences, who
were always willingly to discuss and never hesitated to help me out in whatever way they
could. To name a few, Mrs. Dagmar Dimitrovice, Dr. Katrin Mierdel, Dr. Nguyen Thi Bich
Thuy, Dr. Bernd Binder, Dr. Johannes Baier, Dr. Syvatoslav Shcheka, Dr. Udo Neumann,
Dipl. Volker Presser, Dr. Baldorj Baatartsogt, Dr. Michael Dorn, Dr. Giovanna Laudisio, Mr.
Gregor Seidel, Mr. Alexander Konschak, Dr. Michael Marks, Dr. Martin O’Connell, Miss.
Jasmin Koehler, Miss. Gesa Graser, Mr. Thomas Krumrei and all my friends in the institute.

Last but not least, I would like to express special thanks to my parent, sisters, brothers, my
wife and daughter, who all supported and encouraged me in pursuing my study. Without them
a little could have been achieved. They make my life filled with love and happiness.

v

Table of contents

Acknowledgements ............................................................................................................................ iii
Table of contents ..................................................................................................................................v
List of figures ................................................................................................................................... viii
List of tables .......................................................................................................................................xv
Abstract ........................................................................................................................................ xviii
Zusammenfassung.............................................................................................................................xxi
Part I: Monazite and xenotime solubility in haplogranitic melts.......................................2
1. Introduction.............................................................................................................................3
1.1. General geochemistry of rare earth elements ...........................................................................3
1.2. The abundances of lanthanides in various reservoirs ...............................................................5
1.3. REE in the mantle .....................................................................................................................8
1.4. The oxidation state of REE in geological systems .................................................................10
1.5. Rare earth elements in basaltic systems..................................................................................11
1.5.1. Partition coefficient.................................................................................................................11
1.5.2. REE in different basaltic setting .............................................................................................12
1.6. REE partition coefficient patterns for some major basaltic minerals .....................................14
1.6.1. Olivine ....................................................................................................................................14
1.6.2. Clinopyroxene.........................................................................................................................15
1.6.3. Orthopyroxene ........................................................................................................................16
1.6.4. Garnet......................................................................................................................................17
1.6.5. Plagioclase ..............................................................................................................................18
1.7. Rare earth elements in granitic systems..................................................................................19
1.7.1. Distribution of REE in granitic rocks .....................................................................................19 vi

1.7.2. Crystal structure of monazite and xenotime ...........................................................................20
1.7.3. Monazite and xenotime solubility in granitic melts................................................................22
1.8. Lanthanide tetrad effect ..........................................................................................................26
2. Experimental procedures and methods ..............................................................................29
2.1. Starting materials and preparation of sample capsules...........................................................29
2.1.1. Synthesis of glasses ................................................................................................................29
2.1.2. Hydrothermal growth of monazite and xenotime...................................................................33
2.1.3. Preparation of sample capsules for monazite and xenotime solubility experiments ..............36
2.2. High pressure apparatus and technique...................................................................................37
2.2.1. Cold seal systems (CSS) .........................................................................................................37
2.2.2. Internally heated pressure vessels (IHPV)..............................................................................40
2.3. Investigation of run products ..................................................................................................40
2.3.1. Electron Microprobe Analyses (EMPA).................................................................................40
2.3.2. Powder X-ray diffraction (XRD)............................................................................................42
2.3.3. Near Infrared (FTIR) measurement of hydrous glasses..........................................................42
2.3.4. Raman spectroscopy ...............................................................................................................45
3. Results ....................................................................................................................................46
3.1. The influence of phosphorus on the solubility of monazite in haplogranitic melts................46
3.2. The effect of the alkali/aluminium ratio on monazite and xenotime solubility in
haplogranitic melts .............................................................................................................................54
3.3. The effect of fluorine on REE solubility in haplogranitic melts.............................................69
3.4. The effect of temperature on solubility...................................................................................74
4. Discussion and geological applications ...............................................................................76
4.1. The dissolution mechanism of monazite and xenotime in haplogranitic melts......................76
4.2. Rare earth element fractionation by monazite and xenotime..................................................77
4.3. The origin of the lanthanide tetrad effect in granitic rocks.....................................................78 vii

4.4. The use of monazite solubilities as geothermometer..............................................................81
References ..........................................................................................................................................83


Part II: Solubility of tin in magmatic-hydrothermal fluids ........................................96
II- 1. Introduction .................................................................................................................... ..........97
II- 2. Methods.....................................................................................................................................99
II- 2.1. Inclusion synthesis by the etched plate technique..................................................................99
II- 2.2. Inclusion synthesis by the in-situ cracking technique..........................................................100
II- 2.3. Analytical methods...............................................................................................................102
II- 3. Results .....................................................................................................................................105
II- 4. Discussion ...............................................................................................................................112
II- 5. Implications for fluid–melt partitioning..................................................................................115
II- 6. Conclusions .............................................................................................................................117
References ........................................................................................................................................118



viii

List of figures
Figure 1.1.Schematic chondrite normalized diagram showing idealized REE patterns
(Redrawn from Hollings and Wyman, 2004) ......................................................................7
Figure 1.2. A rare earth plot showing rare earth patterns for primitive mantle (McDonough
and Frey, 1989), lower continental crust (LCC), upper mantle crust (UCC) (Taylor
and McLennan, 1985) and depleted mantle (Salters and Stracke, 2004).............................9
Figure 1.3. A rare earth plot showing rare earth patterns for ocean island basalt (OIB) (Sun
and McDonough, 1989) and mid ocean ridge basalt (MORB) (Taylor and
McLennan, 1985)...............................................................................................................13
Figure 1.4. Rare earth elements patterns of some major mineral in basalts melts. Data sources:
Olivine: Kennedy et al. (1993); Orthopyroxene and Clinopyroxene: Green, T. H. et
al. (2000); Hornblende: Fujimaki et at (1984); Phlogopite and Plagioclas: Arth
(1976); Garnet: Barch (1997).............................................................................................14
Figure 1.5. Plot of the partition coefficient for REE between plagioclase and melt (log scale
vs. atomic number).............................................................................................................18
Figure 1.6. Chondrite normalized diagram showing negative Eu anomalies characteristic of
plagioclase fractionation (Hollings and Wyman, 2004) ....................................................18
Figure 1.7. Typical monazite (CePO ) and xenotime (YPO ) structure. Both arrangements are 4 4
based on [001] chains of alternating phosphate tetrahedra and REEO polyhedra in 8
xenotime or REEO polyhedra in monazite (Modified after Taylor and Ewing, 9
1978) ..................................................................................................................................21
Figure 1.8. Unit-Cell volume of pure REE(PO ) vs. REE ionic radii (Redrawn from Gratz and 4
Heinrich, 1997) ..................................................................................................................22
Figure 1.9. Solubility of monazite (expressed as REE concentration of melt in ppm) in felsic
melts (almost subaluminous compositions) containing approximately 6 wt% H O 2
(Modified after Montel et al., 1993) ..................................................................................24 ix

Figure 1.10. Solubility of REEPO crystals at 800°C, 2 kbar, under water-saturated 4
conditions, in SiO -A1 0 -Na O-K 0 melts.......................................................................24 2 2 3 2 2
Figure 1.11. Typical examples of M- and W-type tetrad effect observed in REE patterns of
granites and seawaters. M1- (Irber, 1999) and M2 patterns (Bau, 1996) are though
to be formed by the chemical complexation in an aqueous-like fluid system during
the final stage of granite crystallization. W1 (De Baar et al., 1985) and W2
(Piepgras and Jacobsen, 1992) showing a well-defined lanthanide tetrad effect with
four concave segments in seawater....................................................................................27
Figure 2.1. Temperature profile for glass synthesis. (a) Decarbonisation and (b) melting................33
Figure 2.2. Raman data showing changes in the crystal structure of the synthetic REE
phosphates. Spectra were obtained using Labram2 Raman spectrometer equipped
with Olympus microscope. ................................................................................................34
Figure 2.3. Typical samples of monazite (LaPO ) and xenotime (HoPO ) X-ray diffraction 4 4
patterns...............................................................................................................................35
Figure 2.4. XRD data for different crystal structures of the synthetic REE phosphates....................35
Figure 2.5. Rietveld refinement of the GdPO sample using XRD data yielded a mix of 4
separate crystals with 80-90 wt% monazite and 10-20 wt% xenotime, respectively. .......35
Figure 2.6. Monazite (CePO ) and xenotime (HoPO ) imaged by SEM ..........................................36 4 4
Figure 2.7. (a) Schematic overview of a cold seal system. (b) Cross section of a cold seal
vessel (bomb): 1- Socket for internal thermocouple; 2- Thermocouple mount; 3-
Screw; 4- Closure cone; 5- small retainer ring; 6- Pressured tubing; 7- Compression
seal; 8- Metal adaptor; 9- Closure bolt; 10- Closure nut; 11-Retainer collar; 12-
Double sealing cone; 13- Pressure vessel (outer - ∅ 39 mm); 14- Filler rod (nickel);
15- Type-K internal thermocouple; 16- Sample chamber (∅ 7 mm); 17- Capsule; 18
– External thermocouple well. ...........................................................................................38
Figure 2.8. Measuring point (MH302) and measuring profile (MH412) of run product at
o800 C and 2 kbar. Step interval away from the crystal glass interface is 20.05 μm..........41 x

Figure 2.9. Near-infrared absorption spectra obtained from a haplogranitic glass containing 6
wt% water. Sample thickness: 224 μm. Dashed line is linear baseline ............................43
Figure 3.1. Phase identification of mica from sample 4P75 (A) Raman spectrum obtained
using a Labram2 spectrometer equipped with Olympus microscope with a red laser
at 632.8 nm and (B) XRD result. .......................................................................................46
oFigure 3.2. Gadolinium concentration profile in glass adjacent to a monazite crystal at 800 C
and 2 kbar for 30-31 days. The solid curve represents the best-fit line of the
diffusion model. The model provide an estimated saturation concentration of REE
(Co) in alkaline haplogranite (ASI =0.8) ...........................................................................50
oFigure 3.3. Gadolinium concentration profile in glass adjacent to a monazite crystal at 800 C
and 2 kbar for 30-31 days. The solide curve represents the best-fit line of the
diffusion model. The model provide an estimated saturation concentration of REE
(Co) in metaluminous haplogranite(ASI =1) .....................................................................51
Figure 3.4. Plot of the average phosphate vs. average REE concentration for solubility
experiments of monazite in haplogranite. A) peralkaline (ASI = 0.8) and B)
metaluminous (ASI = 1) melt composition. The straight line is a fit linear function
of y = A + B/x, where x being phosphate concentration, y being a rare earth
concentration, and A is the equilibrium constant K1, while B is the product of K1
and K2. Fit function used only data of this study. .............................................................53
Figure 3.5. Plot of the average phosphate vs. estimated saturation REE concentration for
solubility experiments of monazite in haplogranites. A) peralkaline (ASI = 0.8) and
B) metaluminous (ASI = 1) melt composition. The straight line is a fit linear
function of y = A + B/x, where x being phosphate concentration, y being a rare
earth concentration, and A is the equilibrium constant K1, while B is the product of
K1 and K2 ..........................................................................................................................53
Figure 3.6. The effect of P O on the apparent solubility product of monazite in water 2 5
osaturated haplogranite melt at 2 kbar and 800 C. ASI refers to the molar Al/(Na+K)
of the melt. The error bars (1σ) are smaller than the symbol size. ....................................54

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