Christian de Capitani

University of Basel | UNIBAS · Department of Environmental Sciences

The Mogok Metamorphic Belt (MMB) of Myanmar formed during the Paleogene collision between the West Burma block and the Shan-Thai block. The MMB is mainly composed of medium to high-grade metamorphic marble, calc-silicate rocks, gneiss, quartzite, peridotite and igneous rocks such as granite, syenite and gabbro. The Mogok area in the central part of...

The Cubito-Moura Unit is a high-P metamorphic succession that occurs in the southern part of the Ossa-Morena Complex (SW Iberian Massif). It includes a series of metasedimentary, metafelsic and metamafic rocks affected by a high-P, low to intermediate-T metamorphic event during Late Devonian times. Geochemistry of the metabasic rocks reveals that t...

The Upper Units of the allochthonous complexes of the NW Iberian Massif constitute a terrane with continental affinity. They represent the vestiges of a Cambrian magmatic arc developed in the periphery of Gondwana (West African Craton) which was involved in the Devonian Variscan collision, undergoing high‐pressure, high‐temperature metamorphism. Th...

High‐pressure (HP) granulites provide telling records of mineral reactions at upper mantle to lower crustal levels and key information on the fate of material in subduction systems. The latter especially applies when they abut eclogite and mantle dunite, because such rock associations are crucial for the understanding of the incompletely known proc...

The Mogok Stone Tract is mainly composed of high-grade metamorphic rocks such as marbles, calc-silicate rocks, gneisses, peridotites and igneous rocks such as granites, syenites and gabbros, etc. Furthermore, the Mogok Stone Tract is eminent for its finest quality gemstones like rubies, sapphires, spinels and others semi-precious gemstones. This st...

Petrographic, petrologic and geochemical investigations on Cr-jadeite rocks from Kenterlau-Itmurundy near Lake Balkhash (Kazakhstan) reveal five different rock groups. Jadeitites show irregular, medium-grained white sections made up of decussate jadeite crystals and fine-grained sections made up of aligned Cr-jadeite. Omphacite jadeitites show a ho...

Fluid inclusion analysis including Raman spectroscopy within in the famous vibrant red spinels from Mansin (East-Mogok) have revealed that the spinels are formed from sulfur-dominated chloride carbonate melt in an extremely reduced acid environment. It is the first comprehensive model for the formation of Burmese spinels that may also help to under...

Understanding the relationships between metamorphism and spatio-thermal variations at convergent plate boundaries is important for deciphering the present-day dynamics of subduction zones. In particular, the interaction between densification due to mineralogical phase transitions and slab pull forces is subject to ongoing investigations. We have th...

Understanding the relationships between density and spatio-thermal variations at convergent plate boundaries is important for deciphering the present-day dynamics and evolution of subduction zones. In particular, the interaction between densification due to mineralogical phase transitions and slab pull forces is subject to ongoing investigations. W...

Worldwide increases in fluvial fine sediment are a threat to aquatic animal health. Fluvial fine sediment is always a mixture of particles whose mineralogical composition differs depending on the sediment source and catchment area geology. Nonetheless, whether particle impact in aquatic organisms differs between mineral species remains to be invest...

Granulites form at low water activities whose exact value is often unknown. This complicates the calculation of equilibrium assemblage phase diagrams and metamorphic pressure (P) and temperature (T) conditions by isopleth thermobarometry, because the fluid characteristics distinctly affect the results. To evaluate the significance of this influence...

Jadeitite boulders from north-central Myanmar show a wide variability in texture and mineral content. This study gives an overview of the petrography of these rocks, and classifies them into five different types: (1) jadeitites with kosmochlor and clinoamphibole, (2) jadeitites with clinoamphibole, (3) albite-bearing jadeitites, (4) almost pure jad...

Petrographic, petrologic and geochemical investigations on kosmochlor-bearing rocks from the so-called Jade Mine Tract, near Hpakan, Kachin State (Myanmar) reveal five different lithologies. Kosmochlor(-bearing)-clinoamphibole-jadeite rocks and schists show aggregates of radiating dark green kosmochlor formed around strongly corroded chromite grain...

[1] This study presents the theory, applicability, and merits of the new THERIAK_D add-on for the open source Theriak/Domino software package. The add-on works as an interface between Theriak and user-generated scripts, providing the opportunity to process phase equilibrium computation parameters in a programming environment (e.g., C or MATLAB®). T...

[1] This study presents the theory, applicability, and merits of the new THERIAK_D add-on for the open source Theriak/Domino software package. The add-on works as an interface between Theriak and user-generated scripts, providing the opportunity to process phase equilibrium computation parameters in a programming environment (e.g., C or MATLAB®). T...

Orogens with multiple (ultra)high‐pressure ((U)HP) and (ultra)high‐temperature ((U)HT) metamorphic events provide a complex but telling record of oceanic and continental interaction. The Early Paleozoic history of the “Heart of China,” the Qinling orogenic collage, offers snapshots of at least three (U)HP and two (U)HT metamorphic events. The prese...

Whiteschists appear in numerous high- and ultrahigh-pressure rock suites and are characterized by the mineral assemblage kyanite + talc (+-quartz or coesite). We demonstrate that whiteschist mineral assemblages are well stable up to pressures of more than 4 GPa but may already form at pressures of 0.5 GPa. The formation of whiteschists largely depe...

We perform bimodal atomic force microscopy measurements on a Br-doped NaCl (001) surface to investigate the mechanisms behind frequency shift and energy dissipation contrasts. The peculiar pattern of the dissipated energy in the torsional channel, related to frictional processes, is increased at the positions of Br impurities, otherwise indistingui...

We conducted a series of experiments on granitoid cataclasites under mid-crustal conditions (Pc∼500 MPa, T=300 °C) and slow displacement rates (10−8 ms−1<ḋ<10−7 ms−1) i.e. within an order of magnitude of plate tectonic velocities. The samples reach high peak strength (1250<τ<1375 MPa) then weaken slightly (by ∼40 MPa) and continue to deform without...

Thermodynamic databases are an essential tool to predict complex equilibrium mineral assemblages and mineral properties like mineral volumes. They consist of numerous thermodynamic data of various minerals, extracted from experiments. Each database follows its own methodology in calculating chemical and physical properties. Therefore a direct compa...

The Tongbai is a segment of the multi-stage Qinling-Tongbai-Hong'an-Dabie-Sulu orogen located in east-central China. Within a narrow slice, Silurian granulites form elongated lenses included in gneisses. Although been sub-ject of several studies, the composition of the fluid present during granulite facies metamorphism has not been addressed yet, b...

The extent to which kinetic barriers to nucleation and growth delay the onset of prograde metamorphic reaction, commonly known as overstepping, is related to the macroscopic driving force for reaction, termed reaction affinity. Reaction affinity is defined in the context of overstepping as the Gibbs free-energy difference between the thermodynamica...

The formation of metamorphic garnet during isobaric heating is simulated on the basis of the classical nucleation and reaction rate theories and Gibbs free energy dissipation in a multi-component model system. The relative influences are studied of interfacial energy, chemical mobility at the surface of garnet clusters, heating rate and pressure on...

In this paper, the term "equilibrium assemblage diagrams" refers to diagrams strictly based on assemblages predicted by Gibbs free energy minimization. The presented Theriak/Domino software uses a unique algorithm of scanning and bookkeeping, which allows to compute completely and automatically a great variety of diagrams: phase diagrams, pseudo-bi...

A new discovery of lawsonite eclogite is presented from the Lancône glaucophanites within the Schistes Lustrés nappe at Défilé du Lancône in Alpine Corsica. The fine-grained eclogitized pillow lava and inter-pillow matrix are extremely fresh, showing very little evidence of retrograde alteration. Peak assemblages in both the massive pillows and wea...

The upper end of the CH4-zone in the External part of the Central Alps of Switzerland results from an oxidation reaction of methane into water and carbon dioxide at 270 ± 5 °C [Tarantola, A., Mullis, J., Vennemann, T., Dubessy, J., de Capitani, C., 2007. Oxidation of methane at the CH4 / H2O–(CO2) transition zone in the external part of the Central...

t is generally accepted that two factors determine the localization of seismogenic areas: the temperature and the fluid pressure. Beneath accretionary sedimentary prisms, the transition to aseismic stable sliding is temperature controlled. The maximum temperature for seismic behavior in crustal rocks is ~350°C. In addition, great earthquake rupture...

Results from forward modelling of garnet growth and U–Th–Pb chemical dating suggest three periods of metamorphism that affected metapelitic rocks of the Rappold Complex (Eastern European Alps). Garnet first grew during Barrovian-type metamorphism, possibly during the Carboniferous Variscan orogeny. The second period of metamorphism produced monazit...

In this paper we show that thermodynamic forward modelling, using Gibbs energy minimisation with consideration of element fractionation into refractory phases and/or liberated fluids, is able to extract information about the complex physical and chemical evolution of a deeply subducted rock volume. By comparing complex compositional growth zonation...

Garnet in metapelites from the Wölz Complex of the Austroalpine crystalline basement east of the Tauern Window characteristically consists of two growth phases, which preserve a comprehensive record of the geothermal history during polymetamorphism. From numerical modelling of garnet formation, detailed information on the pressure–temperature–time...

We present the software program THERIA_G, which allows for numerical simulation of garnet growth in a given volume of rock along any pressure–temperature–time (P–T–t) path. THERIA_G assumes thermodynamic equilibrium between the garnet rim and the rock matrix during growth and accounts for component fractionation associated with garnet formation as...

Considering the localization of seismogenic zones during subduction processes, two factors are generally accepted for their determination: temperature and fluid pressure. Beneath large sedimentary accretion wedges the transition to aseismic stable sliding is temperature controlled. In this case the maximum temperature for seismic behavior in subduc...

Abstract We have used internally-consistent thermodynamic data to present calculated phase equilibria for the system Na2O-CaO-MgO-Al2O3-SiO2-H2O (NCMASH), in the range 0–500° C and 0.1–10 kbar, involving the phases anorthite, glaucophane, grossular, heulandite, jadeite, laumontite, lawsonite, paragonite, prehnite, pumpellyite, stilbite, tremolite,...

With the aim of understanding the mechanisms that control the metamorphic transition from the CH4– to the H2O–(CO2)-dominated fluid zone in the Helvetic domain of the Central Alps of Switzerland, fluid inclusions in quartz, illite “crystallinity” index, vitrinite reflectance, and the stable isotope compositions of vein and whole rock minerals and f...

Garnet in metapelites from the Wolz and Rappold Complexes of the Austroalpine basement east of the Tauern Window typically shows two distinct growth zones. A first garnet generation usually forms the cores of garnet porphyroblasts and is separated by a prominent microstructural and chemical discontinuity from a second garnet generation, which forms...

Magnesian metamorphic rocks with metapelitic mineral assemblage and composition are of great interest in metamorphic petrology for their ability to constrain P–T conditions in terranes where metamorphism is not easily visible. Phase–assemblage diagrams for natural and model magnesian metapelites in the system KFMASH are presented to document how ph...

In subduction zones, many observations indicate that the backarc thermal state is particularly hot and that the upper lithosphere is thin, even if no recent extension episode has occurred. This might result from free thermal convection favored by low viscosities in the hydrated mantle wedge. We perform 2-D numerical experiments of the convective ma...

During the subduction-collision processes, the Earth's crust is squeezed, thickened and uplifted. Therefore rocks will be exposed to changing temperature, pressures and stress regimes and they may undergo metamorphism or partial melting. Meanwhile less attention has been paid to other important aspects of the metamorphic processes. The formation of...

The metamorphic evolution of metapelites from the eastern part of the Monte Rosa nappe and the Camughera–Moncucco unit, both situated in the upper Penninic units SW of the Simplon line, were investigated using microstructural relationships and equilibrium phase diagrams. The units under consideration experienced pre-Alpine amphibolite-facies condit...

A thermodynamic model for the quaternary white mica solid solution with end-members muscovite–Mg-celadonite–paragonite–Fe-celadonite (Ms–MgCel–Pg–FeCel) is presented. The interaction energies for the MgCel–Pg join, the FeCel–Pg join and the ternary interactions were obtained from natural coexisting phengite–paragonite pairs. Phengite–paragonite pai...

An unusual occurrence of blackwall rock occurs on a promontory in Lake Kvesjöen, in the Norwegian Caledonides, at the contact between a lens of ultramafic rock (Fo-En-rock) 200 m in diameter and amphibolite-facies metapelitic country-rocks. The blackwall contains corundum, staurolite, tourmaline and four micas: muscovite, paragonite, margarite and...

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A ternary solid solution model for omphacite with the end-members jadeite (NaAlSi2O6), diopside (CaMgSi2O6) and hedenbergite (CaFeSi2O6) was derived from experimental data from the literature. The subregular solution model, fitted by linear programming, is best suited to omphacites with very little aegirine component in common eclogites. Applying t...

This study analyses the mineralogical and chemical transformations associated with an Alpine shear zone in polymetamorphic metapelites from the Monte Rosa nappe in the upper Val Loranco (N-Italy). In the shear zone, the pre-Alpine assemblage plagioclase + biotite + kyanite is replaced by the assemblage garnet + phengite + paragonite at eclogite fac...

During the subduction-collision processes, the Earth's crust is squeezed, thickened and uplifted. Therefore rocks will be exposed to changing temperature, pressures and stress regimes and they may undergo metamorphism or partial melting. Petrological data on metamorphic rocks provide a good record of P-T-t paths of subduction and continental collis...

In low-grade metamorphic rocks, pumpellyite (Pmp) is an important index mineral found in basic rocks metamorphosed at various pressures and under low-temperature conditions, resulting in the prehnite-pumpellyite (Prh-Pmp), the pumpellyite-actinolite (Pmp-Act) and the blueschist facies. Therefore, pumpellyite is diagnostic of two of the principal fa...

Reactions producing Al-rich index minerals in the south-eastern part of the Lepontine Dome (Central Alps, Switzerland) are investigated using mineral distribution maps, microstructural observations and equilibrium phase diagrams. The apparent staurolite mineral zone boundary corresponds to the paragonite breakdown reaction Pg + Grt + Qtz = Pl + Al2...

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A data set of 71 samples from 42 localities within the external part of the Central Alps is used to compare illite "crystallinity" (IC) and deconvolution fitted peak parameters with fluid inclusion homogenization temperatures from fibre quartz. Fluid inclusions are filled with methane-bearing fluid and were trapped within a temperature range of 200...

In New Caledonia, pumpellyite occurs in association with epidote, chlorite and amphibole in metabasites, metapelites and metatuffs. The metamorphism in New Caledonia is related to two subduction events, one during Cretaceous time and a second one during Oligocene time. Metamorphism in the different metamorphic zones displays an increase in metamorp...

A thermodynamic solution model for FeMg-chlorite has been calibrated to predict the composition and the stability limits of FeMg-chlorite as a function of pressure, temperature and bulk rock composition. Available site-mixing activity models for chlorite do not expand to a Gibbs free energy function required to compute chemical equilibria by G-mini...

Coexisting liquids in the CaO-MgO-SiO2-TiO2 system were synthesized and quenched at ambient pressure in air from 1600 °C using a Rh-Pt resistance furnace and from 1800 to 2000 °C using a laser heated air levitation setup. Compositions of quenched glasses determined by electron microprobe analysis are reproduced in detail by weighted extrapolations...

Coexisting liquids in the SiO2-TiO2-Al2O3 system have been synthesized at 2000 K to 2500 K with a laser-heated air levitation set-up in order to determine the SiO2-TiO2 miscibility gap and its extrapolation to the Al2O3-bearing system. Compositions of quenched coexisting liquids in the SiO2-TiO2 and SiO2-TiO2-Al2O3 system demonstrate the dramatic d...

High-pressure metamorphism in the Penninic Adula nappe (Central Alps, Switzerland) reached eclogite facies conditions. Besides abundant mafic eclogite lenses, very few metapelitic rocks also preserved high-pressure relics, even though most of the felsic lithologies were retrogressed during a later amphibolite facies overprint. Calculations of equil...

In order to simplify the computation of phase relations in multicomponent systems, a generalized excess function based on Margules-type polynomials is presented. It includes a versatile extrapolation method to higher order systems. A less-common formulation of the Gibbs-Duhem equation is used to compute the activity coefficient from Gxs, omitting a...

Compositions of coexisting liquids in binary SiO2-TiO2, alkaline earth CaO-SiO2-TiO2, MgO-SiO2-TiO2, CaO-MgO-SiO2-TiO2 and Al-bearing CaO-SiO2-TiO2-Al2O3 systems have been determined. The excess Gibbs free energy of the melt in binary systems are modeled with subregular solution parameters. Experimental solvus data in ternary systems are reproduced...

Compositions of coexisting liquids in binary SiO2-TiO2, alkaline earth CaO-SiO2-TiO2, MgO-SiO2-TiO2, CaO-MgO-SiO2-TiO2 and Al-bearing CaO-SiO2-TiO2-Al2O3 systems have been determined providing direct constraints to non-ideal solution parameters. The excess Gibbs free energy of the melt in binary systems are modeled with subregular solution paramete...

Compositions of coexisting liquids in the CaO-SiO2-TiO2-Al2O3 system at 1600°C have been determined. In the Alfree ternary system, the miscibility gap is modelled in detail with weighted extrapolation of binary excess Gibbs free energy terms. Addition of few wt% Al2O3 reduces dramatically the extent and consolute temperature of the solvus. Extrapol...

Illite crystallinity, coal rank, percent 2M1 white K-mica polytype, and phase assemblages were determined for shales and shale-matrix melange from various areas in the Diablo Range. This study presents new constraints on the pressure-temperature evolution of the Franciscan units from the Diablo Range. Several shales indicate a lower pressure, possi...

On the basis of experimentally determined stabilities of common zeolites, including analcime, stilbite, heulandite, yugawaralite, laumontite and wairakite, T ‐ XQ,phase relations of these zeolites and plagioclase in the presence of excess quartz and H2O were constructed for the system CaAl2Si208 ‐ NaAlSi3O8 ‐ SiO2 ‐ H2O at Pfluid = 1000, 500, and 3...

A general algorithm for the computation of chemical equilibria in complex systems containing non-ideal solutions has been developed. The method is a G-minimization based on repeated linear and nonlinear programming steps. A computer program (THERIAK) based on this algorithm has been written and was used to solve a great variety of problems, ranging...

The thermodynamic properties of non-ideal binary solutions were investigated. By using reduced temperatures (T/T critical mixing) and comparing the width of the solvi in very different binary systems, a uniform relation for several systems is obtained for which the concept of corresponding solvi is introduced.A graphical method is developed to dete...

The solvus on the Mn-rich side in the system MnCO3-CaCO3 was studied experimentally at 10 kb and lower pressures. The critical point lies at 540 °C and Mn0.68Ca0.32CO3. Reaction rates of demising are extremely sluggish. X-ray calibration curves for (Mn, Ca)CO3 solid solutions are given. Depicting microprobe analyses of about 300 carbonates from man...

Fluid evolution and vein mineralization was investigated in Alpine veins of the Fibbia Granite formed during prograde and retrograde metamorphic conditions. During Alpine collision and uplift in Miocene time (Mullis et al. 1994) varying stress orientations with respect to S_1 lead to the formation of different vein types. V_1 veins formed during pr...

The Lochseiten calc-mylonite is a fine-grained limestone with abundant 0.1 to 1 mm thick veins of calcite, dolomite, quartz, pyrite and organic material. The footwall infrahelvetic flysch at the Lochseite locality consists of fine marly and silty slates alternating with fine- to coarse-grained sandstone layers. The Verrucano formation in the hangin...

Many fluid inclusion studies describing fluid evolution through the Central Alps, Switzerland (i.e. Frey et al., 1980; Mullis, 1987; Mullis et al., 1994) distinguish different fluid zones (HHC, CH_4, H_2O and CO_2) from diagenesis to medium-grade metamorphism. The aim of this study is to investigate the transition from the CH_4 to the H_2O-(CO_2) d...

Vita. Thesis (Ph. D.)--University of British Columbia, 1987. Includes bibliographical references (leaves 128-140). Microfiche. s