Institut für Mineralogie

Thorsten Geisler-Wierwille Dr. rer. nat Diplom-Mineraloge
	Institut für Mineralogie WWU Münster Corrensstrasse 24 D-48149 Münster Fon +49 (0)251 83-33450 Fax +49 (0)251 83-38397 email: tgeisler"at"nwz.uni-muenster.de Office: Room 125  Scientific Career  Research & Teaching  Publications  Links & Downloads

Scientific Career

1995 Graduation in Mineralogy at the University of Hamburg (Germany). 1996-1999 Doctoral degree at the Mineralogisch-Petrographisches Institut in Hamburg (Germany): U-Th-total Pb dating of zircons by electron microprobe: Methodology and application examples 1999-2000 DFG scholar at the Curtin University of Technology in Perth (Australia) 2000-2001 DFG scholar at the Mineralogisch- Petrographisches Institut in Hamburg (Germany) 2001-2002 Postdoctoral Research Associate at the Department of Earth Sciences in Cambridge (UK) since April 2002 Assistant professor (C1) at the Institut für Mineralogie in Münster (Germany)

Research & Teaching

Research interests

Current research mainly focuses on following projects: Stability of ceramic materials proposed as nuclear waste forms under experimental hydrothermal conditions Based on present familiarity with production technology, the two best candidate materials for the immobilization of high-level nuclear waste (e.g., 99Tc, 129I, 79Se, 135Cs, 239Pu, and 137Np) are glasses and crystalline ceramics. The main objectives of the research are to understand the fundamental atomic-scale mechanisms at the fluid-ceramic interface and their dependence on self-irradiation damage, the thermodynamics, and kinetics of fluid-ceramic interaction under moderate P-T conditions expected in deep borehole repositories and near-surface environments. Hydrothermal experiments with natural samples under different physicochemical conditions are linked (i) to detailed studies on natural analogues, which were altered under geological conditions and thus representing real case scenarios, and (ii) to carefully designed hydrothermal experiments with 238Pu-doped synthetic samples. Experiments with 238Pu-doped synthetic samples are carried out in collaboration with the V. G. Khlopin Radium Institute in St. Petersburg (Russia) and the Institute of Transuranium Elements (ITU) in Karlsruhe (Germany). Vibrational spectroscopy of self-irradiated minerals Self-irradiation of minerals due to incorporated actinides such as 238Pu, U, and Th can cause (i) the swelling of the unit-cell due to the accumulation of defects, (ii) amorphization of the structure, and/or (iii) a complex microstructure, which affect their vibrational properties. Raman and infrared spectroscopy are powerful tools to analyse such structural disorder and are used to study the kinetics of thermal recovery and damage accumulation of various self-irradiated minerals. Vibrational spectroscopy of zircon solid-solutions Very little is known about the vibrational and thermodynamic properties of zircon solid solutions of the form (Zr1-x,REEx) (Si1-x,Px)O4 and (Zr1-x, Mx)SiO4 with M = U, Pu, Th, Np. Experimental investigations have shown that these solid solutions are characterized by a large miscibility gap. The reason is a large mismatch of the radius of the substituting atoms, which cause elastic strain fields. The length scale of the strain fields overlap with that of phonons, which allows studying the strain fields by vibrational spectroscopy. U-Th-total Pb dating of U- and Th-bearing minerals by electron microprobe The ability to determine trace U, Th and Pb contents accurately by modern electron microprobes (EMP) has caused renewed interest in chemical dating of U- and Th-bearing accessory minerals like zircon, allanite, pyrochlore, gadolinite, and monazite. Although the U, Th, and Pb analyses by EMP are by far less precise compared to mass-spectrometric analytical techniques, the high spatial resolution of the electron beam potentially allows age relationships to be resolved within altered and/or polygenetic minerals on a µm-scale. Geochronology of the Eckergneis (Harz Mountains, Germany) The Eckergneiss Complex (EGC) is a geologically unique medium- to high-grade mainly metasedimentary metamorphic unit within the Rhenohercynian domain of the Mid-European Variscides. The high-grade metamorphism, which is a matchless feature within the low-grade Rhenohercynian domain, and a “Cadomian” age of the metamorphism obtained from conventional U-Pb zircon data has led to controversial speculations about the tectonic setting of the EGC. Currently, we are carrying out detailed SHRIMP work on detrital zircons and U-Pb dating of metamorphic minerals to unravel the source provenance and the geological history of the EGC. Further research interest is located within the fields of Quaternary Geology and indicator rock studies for the reconstruction of Pleistocene ice-sheet movements.

Co-operations

Boris Burakov (The V.G. Khlopin Radium Institute, St. Petersburg, Russia), Rudy Konings (Institute of Transuranium Elements, Karlsruhe, Germany), Ewan Madrell (British Nuclear Fuels, Sellafield, UK), Gregory R. Lumpkin (University of Cambridge, UK), Robert T. Pidgeon (Curtin University of Technology, Perth, Australia), Ulrike Poller (MPI Mainz, Germany), Meinert K.W. Rahn (HSK, Villigen-HSK, Schweiz), Abdel A. Rashwan (Banha University, Cairo, Egypt), Susana Ríos (University of Cambridge, UK), Helmut Schleicher (University of Hamburg, Germany), Jochen Schlüter (University of Hamburg, Germany), Anne-Magali Seydoux-Guillaume (Université Paul Sabatier, Toulouse, France), Kostya Trachenko (University of Cambridge, UK), Shrinivas Viladkar (University of Bombay, India), Roland Vinx (University of Hamburg, Germany), Michael Wiedenbeck (GeoForschungsZentrum Potsdam, Germany), Richard Wirth (GeoForschungsZentrum Potsdam, Germany), Ming Zhang (University of Cambridge, UK)

Teaching

I have held following lectures in the last 5 years: At the Mineralogisch-Petrographisches Institut, University of Hamburg (Germany) Macroscopic rock determination (practical) Introduction to statistics for geoscientists / Modelling of magmatic processes (external university teaching position) Introduction to electron microprobe analysis (external university teaching position) At the Department of Earth Sciences, University of Cambridge (UK) Module 2: Disordered materials: Radiation damage Module A: Structure of materials (Practical of Materials and Mineral Sciences) At the Institut für Mineralogie, University of Münster  Optics/polarisation microscopy Vibrational spectroscopy in mineralogy Diffusion in condensed matter Mineralogical practical (Raman and IR spectroscopy, X-ray diffraction analysis)

Computer programs

ChemAge: a Windows program for the calculation of chemical U-Th-total Pb age of accessory minerals, including algorithms for electron microprobe data reduction (program BgReg). CirMap: a Windows program for the presentation of indicator rock counts according to the Circle-Map-Method of Smed (1992). Both programs are running under Windows 95/98/2000 and NT and are available on request.

Publications

Reviewed Articles

Geisler T. (1996) The Permocarboniferous dolerites in Scania, south Sweden: Petrographical and geochemical characteristics and their significance as Indicator Geschiebe. Archiv für Geschiebekunde, 2 (2): 105-117 (in German). Geisler T. (1999) CirMap: A 32 bit Windows program for the analysis and presentation of indicator counts by the Circle Map Method. Archiv für Geschiebekunde, 2 (8), 597-600 (in German). Geisler T. and Schleicher, H. (2000) Improved U-Th-total Pb dating of zircons by electron microprobe using a new background modeling method and Ca as a chemical criterion of fluid-induced U-Th-Pb discordance in zircon. Chem. Geol., 163, 269-285. Geisler T. and Schleicher, H. (2000) Composition and U-Th-total Pb model ages of polygenetic zircons from the Vånga granite, south Sweden: An electron microprobe study. Geol. Fören. Förh., 122, 227-235. Geisler T., Ulonska M., Schleicher H., Pidgeon R.T., and van Bronswijk W. (2001) Leaching and differential recrystallization of metamict zircon under experimental hydrothermal conditions. Contrib. Mineral. Petrol., 141, 53-65. Geisler T., Pidgeon R.T., van Bronswijk W., and Pleysier R. (2001) Kinetics of thermal recovery and recrystallization of partially metamict zircon: a Raman spectroscopic study. Eur. J. Mineral., 13, 1163-1176. Geisler T. and Pidgeon R.T. (2001) Significance of radiation damage on the integral SEM cathodoluminescence intensity of zircon: An experimental annealing study. N. Jhb. Mineral. Monatsh., 10, 433-445. Geisler T. (2002) Isothermal annealing of partially metamict zircon: evidence for a three-stage recovery process. Phys. Chem. Min., 29, 420-429. Geisler T. and Pidgeon R.T. (2002) Raman scattering from metamict zircon: Comments on “Metamictisation of natural zircon: accumulation versus thermal annealing of radioactivity-induced damage” by Nasdala et al., 2001 (Contributions to Mineralogy and Petrology, 141, 125-144). Contrib. Mineral. Petrol., 143, 750-755. Geisler T., Pidgeon R.T., van Bronswijk W., and Kurtz R. (2002) Transport of uranium, thorium, and lead in metamict zircon under low-temperature hydrothermal conditions. Chem. Geol., 191, 141-154. Geisler T., Rashwan A.A., Rahn M., Poller U., Zwingmann H., Pidgeon R.T., Schleicher H., and Tomaschek F. (2003) Low-temperature hydrothermal alteration of natural metamict zircons from the Eastern Desert, Egypt. Mineral. Mag., 67, 485-508. Geisler T., Zhang M., and Salje E.K.H. (2003) Recrystallization of almost fully amorphous zircon under hydrothermal conditions: An infrared spectroscopic study. J. Nucl. Mater., 320, 280-291. Geisler T., Pidgeon R.T., Kurtz R., van Bronswijk W., and Schleicher H. (2003) Experimental hydrothermal alteration of partially metamict zircon. Am. Mineral., 86, 1496-1518. Geisler T., Trachenko K., Ríos S., Dove M., and Salje E.K.H. (2003) Impact of self-irradiation damage on the aqueous durability of zircon (ZrSiO4): Implications for its suitability as nuclear waste form. J. Phys: Condens. Matter, 15, L597-L605. Trachenko K., Dove M.T., Geisler T., Todorov I., and Smith B. (2004) Radiation damage effects and percolation theory. J. Phys.: Condens. Matter, 16, S2623-S2627. Trachenko K., Dove M.T., Pruneda M., Artacho E., Salje E.K.H., Geisler T., Todorov I., and Smith B. (2004) Radiation-induced structural changes, percolation effects, and resistance to amorphization. Mat. Res. Soc. Symp. Proc., 792, R.6.2.1. Zhang M., Salje E.K.H., Ewing R.C., Daniel P., and Geisler T. (2004) Application of near-infrared FT-Raman spectroscopy in metamict and annealed zircon: oxidation state of U ions. Phys. Chem. Min., 31, 405-414. Geisler T., Seydoux-Guillaume A.-M., Wiedenbeck M., Berndt J., Wirth R., Zhang M., Mihailova B., Putnis A., Salje E.K.H., and Schlüter J. (2004) Periodic precipitation pattern formation in hydrothermally treated, metamict zircon. Am. Mineral., 89, 1341-1347. Geisler T., Berndt J., Meyer H.-W., Pollok K., Putnis A. (2004) Low-temperature aqueous alteration of crystalline pyrochlore: Correspondence between nature and experiment. Mineral. Mag., 68, 905-922. Geisler T., Burakov B.E., Yagovkina M., Garbuzov V., Zamoryanskaya M., Zirlin V., and Nikolaeva L. (2005) Structural recovery of self-irradiated natural and 238Pu-doped zircon in an acidic solution at 175°C. J. Nucl. Mater., 336, 22-30. Geisler T., Vinx R., Martin-Gombojav N., and Pidgeon R.T. (2005) Ion microprobe (SHRIMP) dating of detrital zircon grains from quartzites of the Eckergneiss Complex, Harz Mountains (Germany): Implications for the provenance and geological history. Int. J. Earth Sci., 94, 369-384. Geisler T., Seydoux-Guillaume A.-M., Pöml P., Golla-Schindler U., Berndt J., Wirth R., Pollok K., Janssen A., and Putnis A. (2005) Experimental hydrothermal alteration of crystalline and radiation-damaged pyrochlore. J. Nucl. Mater., 344, 17-23. Geisler T., Pöml P., Stephan T., Janssen A., and Putnis A. (2005) Experimental observation of an interface-controlled pseudomorphic replacement reaction in a natural crystalline pyrochlore. Am. Mineral., 90, 1683-1687. Geisler T., Burakov B.E., Zirlin V., Nikolaeva L., and Pöml P. (2005) A Raman spectroscopic study of high-uranium zircon from the Chernobyl “lava”. Eur. J. Mineral., 17, 883-894. Geisler T., Popa K., Konings R.J.M., Popa A.F. (2006) A Raman spectroscopic study of the phase transition of BaZr(PO4)2: evidence for a trigonal structure of the high-temperature polymorph. J. Solid State Chem., 197, 1489 - 1495. Pöml P., Geisler T., and Konings R.J.M. (2006) High-temperature heat capacity of zirconolite (CaZrTi2O7). J. Chem. Thermodynamics, 38, 1013-1016. Popa K., Konings R.J.M., Beneš, Geisler T., and Popa A.F. (2006) Thermodynamic and spectroscopic studies of the phase transitions of BaHf(PO4)2. Thermochem. Acta, 451, 1-4. Popa K., Konings R.J.M., Bouëxière D., Popa A.F., and Geisler T. (2006) Synthesis and characterisation of BaMIV(PO4)2 in the view of conditioning of the actinides. Adv. Sci. Techn., 45, 2012-2017. Putnis C.V., Geisler T., Stephan T., Schmid-Beurmann P., and Giampaolo C. (2007) An experimental study of the replacement of leucite by analcime. Amer. Mineral., 92, 19-26. Pidgeon R.T., Nemchin A.A., van Bronswijk W., Geisler T., Meyer C., Compston W., and Williams I.S (2007) Complex history of a zircon aggregate from lunar breccia 73235. Geochim. Cosmochim. Acta, 71, 1370-1381.  Popa K., Konings R.J.M., and Geisler T. (2007) High-temperature calorimetry of (La1-xLnx)PO4 solid solutions. J. Chem. Thermodynamics, 39, 236-239. Geisler T., Schaltegger U., and Tomaschek F. (2007) Re-equilibration of zircon in aqueous fluids and melts. Elements, 3, 45-51. Menneken M., Nemchin A.A., Geisler T., Pidgeon R.T., and Wilde S.A. (2007) Hadean diamonds in zircon from Jack Hills, Western Australia. Nature, 448, 917-920. Pöml P., Menneken M., Stephan T., Niedermeier D., Geisler T., and Putnis A. (2007) Mechanism of hydrothermal alteration of natural self-irradiated and synthetic titanate-based pyrochlore. Geochim. Cosmochim. Acta, 71, 3311-3322. Popa K., Bregiroux D., Konings R.J.M., Gouder T., Popa A.F., Geisler T., and Raison P.E. (2007) The chemistry of the phosphates of barium and tetravalent cations with 1:1 stoichiometry. J. Sol. State Chem., 180, 2346-2355. Geisler T., Pollok K., Burakov B.E., and Garbuzov M.V. (2007) Raman scattering of nano-zircon: Implications for the interpretation of Raman spectra from partially metamict zircon. Contrib. Mineral. Petrol., submitted. Geisler T. (2007) The Eckergneiss Complex (Harz, Germany). In: T. McCann (ed.) The Geology of Central Europe. Geol. Soc. London, Spec. Publ., in press. Nemchin A.A., Whitehouse M.J., Menneken M., Geisler T., Pidgeon R.T., and Wilde S.A. (2007) Light carbon reservoir in the early Earth revealed by diamond and graphite inclusions in 3050 to 4250 Myr old zircon from Jack Hills, Western Australia. Nature, in review. Geisler T., Pollok K., Burakov B.E., and Garbuzov M.V. (2007) Raman scattering of nano-zircon: Implications for the interpretation of Raman spectra from partially metamict zircon. Phys. Chem. Min., in review. Janssen A., Pöml P., Benes A., Geisler T., and Konings R.J.M. (2007) High-temperature heat capacity of Gd2Ti2O7. J. Chem. Thermodynamics, submitted. Manuscripts (in preparation) Nemchin A.A., Timms N., Geisler T., and Pidgeon R.T. (in prep.) History of the Moon recorded by the oldest zircon grain. To be submitted to Science. Geisler T., Scheiter D., Stephan, T., and Janssen A. (in prep.) Nuclear waste glass alteration mechanism revised. To be submitted to Science. Plümper O., Schepers A., Beerlage K., and Geisler T. (in prep.) Hydrothermal stability of Y-stabilized ceria-zirconia solid solutions. To be submitted to J. Nucl. Mater.  Golla-Schindler U. and Geisler T. (in prep.) Microstructure of experimentally altered, radiation-damaged zircon: A transmission electron microscopy study. To be submitted to Phys. Chem. Minerals. Niedermeier D.R.D., Putnis A., Geisler T., Golla-Schindler U., and Putnis C. (in prep.) The mechanism of cation and oxygen isotope exchange in alkali feldspars under hydrothermal conditions. To be submitted to Contrib. Mineral. Petrol. Soman A., Geisler T., Tomaschek F., Berndt J., Scherer E., and Putnis A. (in prep.) Alteration of crystalline zircon solid solutions: A case study of zircon from an alkali pegmatite from Malawi. To be submitted to Contrib. Mineral. Petrol. Pollok K., Geisler T., and Putnis A. (in prep.) The hydrothermal replacement of chlorapatite by hydroxyapatite: Textural observations and 18O isotopic tracing. To be submitted to Amer. Mineral.

Conference Abstracts

Vinx R. and Geisler T. (1995) A new approach for high-resolution reconstruction of ice-sheet flow paths: The indicator sequence method. Terra Nova, 7, 267. Geisler T. and Schleicher H. (1996) U-Th-Pb dating of zircons by electron microprobe. Beih. Eur. J. Mineral., 8, 68 (in German). Geisler T. and Vinx R. (1996) Classification of tholeiitic and calc-alkaline basic rocks using the diagram Sr/Al vs. SiO2. Beih. Eur. J. Mineral., 8, 69 (in German). Vinx R., Geisler T., and Reese F. (1996) High-resolution of ice-sheet flow paths: Methodology and application of the indicator sequence method. Beih. DEUQUA’96, Gmunden, 46 (in German). Geisler T. and Schleicher H. (1997) Routine U-Th-Pb dating of zircons in thin sections by electron microprobe. Beih. Eur. J. Mineral., 9, 116. Ong K., Geisler T., and Niecke M. (1999) Proton-induced X-ray microanalysis (PIXE): III.1.6: Age dating of zircons. I. Institut für Experimentalphysik, Universität Hamburg, Jahresbericht 1997-1999, 57-59. Vellmer C. and Geisler T. (1999) Svecofennian crustal components within the Southwest Swedish Gneiss Province: Indications from chemical age dating of single zircons by electron microprobe. EGU, J. Conf. Abs., 4, 153. Schumann A., Barifaijo E., and Geisler T. (1999) Preliminary results on the origin of granitoid rocks of Eastern Uganda and around Kampala: Magmatic or metasomatic. J. African Earth Sci., 28, 71-72. Geisler T. (1999) ChemAge: a 32-bit Windows program for chemical age calculations and the graphical data presentation. Beih. Eur. J. Mineral., 11, 154. Geisler T., Ulonska M., and Schleicher H. (1999) Hydration-related ion exchange processes in metamict zircon under hydrothermal conditions: a preliminary experimental study. Beih. Eur. J. Mineral., 11, 155. Möller A., Geisler T., Schleicher H., and Todt W. (1999) The carbonatite of Pakkanadu, southern India: indications for a metamorphic overprint. Beih. Eur. J. Mineral., 11, 186. Möller A., Geisler T., Schleicher H., Todt W., Viladkar, S.G., and Subramanian, V. (2001) Interrelationships between carbonatite-pyroxenite-syenite complexes of Southern India. Symposium on carbonatites and associated alkaline rocks & field workshop on carbonatites of Tamil Nadu, 12th -18th Febr., Chennai, India, Abstr. Vol., 15-16. Geisler T., Pidgeon R.T., and van Bronswijk W. (2001) Alteration of zircon under experimental hydrothermal conditions. EGU, J. Conf. Abs., 6, 684. Geisler T. (2001). A macroscopic model for chemical transport in metamict zircon. Beih. Eur. J. Mineral., 13, 61. Geisler T., Nergui G., and Vinx R. (2001) A detrital zircon provenance study on metasediments of the Eckergneiss unit, Harz Mountains, Germany: application of the U-Th-total Pb dating method. Beih. Eur. J. Mineral., 13, 61. Geisler T., Zwingmann H., Rashwan A. A., and Schleicher H. (2001) Low-temperature hydrothermal alteration of natural zircon: A case study on metamict zircons from the Eastern Desert, Egypt. Beih. Eur. J. Mineral., 13, 62. Poller U., Geisler T., Huth, J., and Pidgeon R.T. (2002) Understanding CL in natural zircons. Goldschmidt Conference Abstracts, A609. Pidgeon R.T., Nemchin A.A., Geisler T., and van Bronswijk W. (2002) Radiation damage in > 4 Ga zircons from the Jack Hills, Western Australia. Goldschmidt Conference Abstracts, A601. Geisler T., Vinx R., Pidgeon R.T., and Martin G. (2002) A SHRIMP study on detrital-zircons from quartzites of the Ecker Gneiss unit, Harz Mountains (Germany). Beih. Eur. J. Mineral., 14, 50. Geisler T., Zhang M., Farnan I., and Salje E.K.H. (2002) Recrystallization of heavily metamict zircon under different hydrothermal P-T-t-X conditions. Beih. Eur. J. Mineral, 14, 51. Rahn M.K., Pidgeon R.T., and Geisler, T. (2002) Radiation damage in zircon and its significance for low-temperature geochronology. SMPG Annual meeting, Davos, September 18-20, 2002, Abstract volume. Geisler T., Zhang M., Wiedenbeck M., Salje E.K.H., and Putnis A. (2003) Pattern formation in metamict zircon under hydrothermal conditions. EUG, Geophys. Res. Abstracts, 5, 07196. Geisler T., Poller U., Huth J., and Meyer H.-W. (2003) Cathodoluminescence of zircon. Beih. Eur. J. Mineral., 15, 63. Geisler T., Trachenko K., S. Ríos, Dove M., and Salje E.K.H. (2003) Percolation-controlled alteration of metamict zircon under hydrothermal conditions. Beih. Eur. J. Mineral., 15, 64. Geisler T., Putnis A., Golla-Schindler U., Seydoux-Guillaume A.-M., Janssen A. (2004) Hydrothermal stability of crystalline and radiation-damaged pyrochlore. Goldschmidt Conference Abstracts, A111. Pollok K., Geisler T., Putnis A. (2004) How does a replacement front proceed? Observations on chlorapatite-hydroxylapatite replacements. Goldschmidt Conference Abstracts, A184. Golla-Schindler U., Veintemillas-Verdaguer S., Geisler T., and Putnis A. (2004) Investigations of nanoparticles and interfaces by using the O K-edge ELNES. Proc. 13th Eur. Microscopy Congress, Materials Sciences Vol. 2, 551-552. Lagos M., Ballhaus C., Holzheid A., Münker C., Berndt J., Geisler T. (2004) The partitioning behavior of Pb between metal and silicate melt: first results and possible implications for terrestrial core formation. Beih. Eur. J. Mineral., 16, 79. Pollok K., Geisler T., Putnis A. (2004) The replacement of chlorapatite by hydroxyapatite under hydrothermal conditions: Mechanisms and kinetics of re-equilibration. Beih. Eur. J. Mineral., 16, 107. Geisler T., Seydoux-Guillaume A.-M., Pollok K., Berndt J., Janssen A., and Putnis A. (2004) Mechanisms of the interaction of crystalline and radiation-damaged pyrochlore with hydrothermal fluids. Proc. 11th Symposium on Thermodynamics of Nuclear Materials in Karlsruhe, September 6-9, 36. Konings R.J.M., Geisler T., Popa, K. (2004) Investigation of the thermodynamic and vibrational properties of ceramics for the immobilization of actinides. ITU Annual Report 2004 (EUR 21511 EN), 47-48. Geisler T., Vinx R., Martin-Gombojav N., and Pidgeon R.T. (2005) Ion microprobe (SHRIMP) dating of detrital zircon grains from quartzites of the Eckergneiss Complex (Harz Mountains, Germany). Exkursionsführer und Veröffentlichung der Deutschen Gesellschaft für Geowissenschaften (DGG), 227, 11-12. Pöml P., Geisler T., Konings R.J.M. (2005) Structural investigations and thermodynamics of nuclear waste form zirconolite ceramics. Beih. Eur. J. Mineral., 17, 104. Menneken M., Geisler T., Stephan T., Pöml. P., and Putnis A. (2005) Hydrothermal alteration mechanism of US-type nuclear waste form pyrochlore. Beih. Eur. J. Mineral., 17, 89. Pollok K., Geisler T., Burakov B.E., Garbuzov V.M., Putnis A. (2005) Synthesis and characterization of uranium-doped nanocrystalline zircon. Beih. Eur. J. Mineral., 17, 104. Putnis C.V. and Geisler T. (2005) The replacement of leucite by analcime. Beih. Eur. J. Mineral., 17, 105. Geisler T., Burakov B.E., Zirlin V., Nikolaeva L., and Pöml P. (2005) Local structural heterogeneity in high-uranium zircon from the Chernobyl “lava” studied by Raman spectroscopy. Beih. Eur. J. Mineral., 17, 44. Van Bronswijk W., Geisler T., Pidgeon R.T. (2005) Probing the hydrothermal alteration of partially metamict zircon with Raman spectroscopy. Proc. 6th Austr. Conference on Vibrational Spectroscopy, Sydney, 31-32. Golla-Schindler U., Geisler T., and Putnis A. (2005) TEM investigations of hydrothermally treated zircons. PSI Proceedings 05-01, ISSN 1019-6447, 342. Putnis C.V., Geisler T., Stephan T., and Giampaolo C. (2006) 18O as a tracer to determine the mechanism of replacement of leucite by analcime. EGU, J. Conf. Abs. (submitted). Putnis C.V. and Geisler T. (2006) Compositional and textural equilibration of minerals in contact with aqueous crustal fluids. Geochim. Cosmochim. Acta 70, Suppl. 1, 44. Pöml P., Menneken M., Stephan T., Niedermeier D., Geisler T., and Putnis A. (2006) 18O-tracing of the hydrothermal alteration of pyrochlore. Geochim. Cosmochim. Acta 70, Suppl. 1, 34. Golla-Schindler U., Pöml. P., Geisler T., and Putnis A. (2006) Energy-filtered TEM/STEM applied to mineralogical issues. Geochim. Cosmochim. Acta 70, Suppl. 1, 208. Soman A., Tomaschek F., Berndt J., Geisler T., and Scherer E. (2006) Hydrothermal re-equilibration of zircon from an alkali pegmatite of Malawi. Beih. Eur. J. Mineral., 18, 132. Geisler T. and Tomaschek F. (2006) Re-equilibration textures of zircon: What are we actually dating? Beih. Eur. J. Mineral., 18, 44. Popa K., Konings R.J.M., Geisler T., Pöml P. (2006) Immobilization of IV+ cations in ceramics with monazite/brabantite structure. Czechoslovak Journal of Physics, 56, Suppl., in press. Popa K., Geisler T., Konings R.J.M. (2006) Thermodynamic and spectroscopic studies of the phase transitions of BaHf(PO4)2. ESTAC9, Krakow, Abstract volume, 79. Putnis A., Janssen, A., Geisler T., and Putnis C.V. (2007) The mechanism of hydrothermal alteration of ilmenite. Geophys. Res. Abstracts, 9, 06889. Geisler T., Pöml P.,A., Soman A., Menneken M., Plümper O.,Schepers A., Scheiter D., and Niedermeier D.R.D. (2007) Evaluation of the long-term performance of potential nuclear waste form materials. Frontiers in Mineral Sciences 2007, Programme and Abstracts, 197-198. Pöml P., Geisler T., Menneken M., Stephan T., Niedermeier D.R.D., and Putnis A. (2007) Mechanism of hydrothermal alteration of natural self-irradiated and synthetic crystalline titanate-based pyrochlore. Frontiers in Mineral Sciences 2007, Programme and Abstracts, 198-199.  Soman A., Geisler T., Tomaschek F., and Putnis A. (2007) Re-equilibration of natural pyrochlore from Malawi in aqueous fluids. Frontiers in Mineral Sciences 2007, Programme and Abstracts, 199-200. Putnis C.V. and Geisler T. (2007) A mechanism of ion exchange in fluid-mineral interaction. Frontiers in Mineral Sciences 2007, Programme and Abstracts, 277-278. Scheiter D., Janssen A., and Geisler T. (2007) Formation of Liesegang rings in borosilicate glass during experimental alteration. Geochim. Cosmochim. Acta, 71, Suppl. 1, A887. Menneken M., Nemchin A.A., Geisler T., Wilde S.A., and Pidgeon R.T. (2007) Oldest terrestrial diamonds in zircon from Jack Hills, Western Australia. Geochim. Cosmochim. Acta, 71, Suppl. 1, A652. Niedermeier D.R.D., Putnis A., and Geisler T. (2007) Hydrothermal alkali and oxygen-isotope exchange in alkali feldspars controlled by dissolution reprecipitation mechanisms. Geochim. Cosmochim. Acta, 71, Suppl. 1, A717. Janssen A., Geisler T., Putnis A., and Putnis C.V. (2007) The mechanism of oxidation and “leaching” of ilmenite during natural and experimental alteration. Geochim. Cosmochim. Acta, 71, Suppl. 1, A450. Putnis A., Janssen A., Geisler T., Putnis C.V., and Golla-Schindler U. (2008) The mechanism of experimental oxidation and leaching of ilmenite in acid solution. Submitted to the 9th International Congress for Applied Mineralogy (ICAM) in Brisbane, Australia 2008.

Links & Downloads

no contents