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Relics suggesting an early high-pressure eclogite facies stage have been identified in the garnet and clinopyroxene-bearing amphibolites of the Tatra Mountains, in the Variscan basement of the Western Carpathians, Slovakia. In these rocks, primary omphacite (Cpx I) has been wholly converted to symplectites of diopside (Cpx II) and plagioclase. Apart from minor inclusions in the garnet cores, amphibole...
High-pressure clinopyroxenes in metasomatic mafic rocks (rodingites and metagabbros containing titanoclinohumite) and eclogites from the Voltri Massif (Ligurian Western Alps) retain primary, two-phase aqueous inclusions (H 2 O + NaCl ± KCl). In the metasomatized rocks the inclusions align with the c axes and the cleavage planes of diopside. The eclogites display mylonitic textures: primary...
In this paper the first fluid-inclusion data are presented from Late Archaean Scourian granulites of the Lewisian complex of mainland northwest Scotland. Pure CO 2 or CO 2 -dominated fluid inclusions are moderately abundant in pristine granulites. These inclusions show homogenization temperatures ranging from − 54 to + 10 °C with a very prominent histogram peak at − 16 to − 32 °C....
The densities of fluid inclusions in quartz from high-pressure, low-temperature metamorphic rocks are generally inconsistent with the P-T conditions derived from solid-phase equilibria. Therefore, some process of change must regularly have occurred during exhumation. However, evidence of decrepitation is frequently lacking. Consideration of the rates of change of P and T in metamorphic rocks shows...
The densities of fluid inclusions in quartz from high-pressure, low-temperature metamorphic rocks are generally inconsistent with the P-T conditions derived from solid-phase equilibria. Therefore, some process of change must regularly have occurred during exhumation. However, evidence of decrepitation is frequently lacking. Consideration of the rates of change of P and T in metamorphic rocks shows...
The Ogcheon metamorphic belt (OMB) comprises Late Proterozoic to Paleozoic metasedimentary and metavolcanic sequences which are intruded by Mesozoic granitoid plutons. To delineate the metamorphic evolution of the OMB, we have investigated mineral parageneses, metamorphic reactions and P-T conditions of pelitic and mafic schists in the Chungju area, northwestern part of the OMB. The regional metamorphic...
The metabasite bodies of the Mt. Emilius continental unit (western Italian Alps) underwent a stage of Alpine eclogite-facies metamorphism (1.1-1.3 GPa and 450-550 o C) accompanied by polyphase deformation and recrystallization. The metabasites consist of two main rock types: (1) eclogites (omphacite+garnet+glaucophane+epidote+phengite/paragonite) preserving no relics of their precursors; (2)...
Idiomorphic quartz crystals in topaz-bearing granite from the Salmi batholith contain primary inclusions of silicate melt and abundant mostly secondary aqueous fluid inclusions. Microthermometric measurements on melt inclusions give estimates for the granite solidus and liquidus of 640-680 o C and 770-830 o C, respectively. Using published solubility models for H 2 O in granitic...
Fluid inclusions whose composition can be approximated by the ternary system NaCl-CaCl 2 -H 2 O are common in the Fe-oxide-Cu-Au deposits, and associated alteration, in the Cloncurry hydrothermal system, NW Queensland, Australia. Detailed microthermometric work indicates that a multi-staged CaCl 2 -bearing fluid trapping was involved during the formation of mineralization and...
The paper gives an overview of the phase relations in carbonic fluid inclusions with pure, binary and ternary mixtures of the system CO 2 -CH 4 -N 2 , compositions, which are frequently found in geological materials. Phase transitions involving liquid, gas and solid phases in the temperature range between -192 o C and 31 o C are discussed and presented in phase...
The fluid inclusions preserved in high and ultrahigh pressure rocks provide direct information on the compositions of fluid phases evolved during subduction zone metamorphism, and on fluid-rock interactions occurring in such deep environments. Recent experiments and petrologic studies of eclogite-facies rocks demonstrate that stability of a number of hydrous phases in all rock systems allows fluid...
The principal aim of this paper is to consider some of the special problems involved in the study of fluid inclusions in ore deposits and review the methodologies and tools developed to address these issues. The general properties of fluid inclusions in hydrothermal ore-forming systems are considered and the interpretation of these data in terms of fluid evolution processes is discussed. A summary...
H 2 O, CO 2 , CH 4 , CO, H 2 and O 2 are the most important species in crustal fluids. The composition of these C-O-H fluids can be calculated if the pressure, temperature, carbon activity, and either the oxygen fugacity or the atomic H/O ratio of the fluid is known. The calculation methods are discussed and calculation results are illustrated with isobaric...
Fluid inclusions in olivine and pyroxene in mantle-derived ultramafic xenoliths in volcanic rocks contain abundant CO 2 -rich fluid inclusions, as well as inclusions of silicate glass, solidified metal sulphide melt and carbonates. Such inclusions represent accidentally trapped samples of fluid- and melt phases present in the upper mantle, and are as such of unique importance for the understanding...
Radiogenic isotopes studied in fluid inclusions are still a limited field, with great potential for expansion as analytical techniques improve. The main limitation for Sr, Ar and He isotope work is the very small number of radiogenic atoms produced in a typical fluid inclusion. The requirements to analysts are correspondingly high. Examples show that isotopic tracing on fluid inclusion fluids can...
Aqueous solutions that contain volatile (gas) components are one of the most important types of fluid in the Earth's crust. The record that such fluids have left in the form of fluid inclusions in minerals provides a wealth of insight into the geochemical and petrologic processes in which the fluids participated. This article reviews the systematics of CO 2 -H 2 O fluid inclusions...
The transmission electron microscope (TEM) allows a detailed characterization of textural and chemical features of fluid inclusions (shape, inner compositions and inner textures), at a resolution higher than that attainable with an optical microscope (OM). TEM investigation indicates that most fluid inclusions appear as perfectly euhedral negative crystals, with variable shape (from prismatic to equant)...
A procedure of fluid inclusion studies is proposed with emphasis on the criteria of selecting fluid inclusions for detailed (microthermometry and spectroscopic) analysis. An overview of descriptive and genetic classifications of fluid inclusions in single crystals and in massive rocks is given with the intention of further differentiating the commonly used terms 'primary' and 'secondary' fluid inclusions...
Basic principles for the study of fluid inclusions in metamorphic rocks are reviewed and illustrated. A major problem relates to the number of inclusions, possibly formed on a wide range of P-T conditions, having also suffered, in most cases, extensive changes after initial trapping. The interpretation of fluid inclusion data can only be done by comparison with independent P-T estimates derived from...
Some of the major problems in sedimentary geology can be solved by using fluid inclusions in sedimentary and diagenetic minerals. Important fluids in the sedimentary realm include atmospheric gases, fresh water of meteoric origin, lake water, seawater, mixed water, evaporated water, formation waters deep in basins, oil, and natural gas. Preserving a record of the distribution and composition of these...
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