Fluid Inclusion Trails in Granite Quartz: Evidence for Aqueous Fluid Infiltration in the Oughterard Granite, Eastern Connemara

2006 ◽  
Vol 24 (-1) ◽  
pp. 1-11 ◽  
Author(s):  
Martin Feely ◽  
James Conliffe ◽  
Kevin Faure ◽  
Siobhain Power
Keyword(s):  
Fluid Inclusion ◽  
Aqueous Fluid ◽  
Fluid Infiltration ◽  
Inclusion Trails

Isotope geochemistry and origin of illite-smectite and kaolinite from the Seilitz and Kemmlitz kaolin deposits, Saxony, Germany

Clay Minerals ◽  
2003 ◽  
Vol 38 (1) ◽  
pp. 95-112 ◽  
Author(s):  
H. A. Gilg ◽  
B. Weber ◽  
J . Kasbohm ◽  
R. Frei
Keyword(s):  
Fluid Inclusion ◽  
Melt Inclusions ◽  
Isotope Geochemistry ◽  
Volcanic Rocks ◽  
Volcanic Glass ◽  
Aqueous Fluid ◽  
Silicic Volcanic ◽  
Inclusion Trails ◽  
Kaolin Deposit ◽  
Glassy Silicate

AbstractResidual clays that developed on Permian and Carboniferous glass-rich silicic volcanic rocks (pitchstones, ignimbrites) at the Seilitz and Kemmlitz kaolin deposits, Saxony, Eastern Germany, contain locally abundant lath-shaped illite-rich illite-smectite mixed-layer minerals (I-S). Analyses by XRD and TEM-AES reveal a large illite percentage (>∼90%) and R3 ordering in I-S from Seilitz (>∼90%) and smaller illite percentage (∼70%) and R1 ordering in I-S from Kemmlitz. The clays never suffered a deep burial and there is no geological, petrographic or fluid inclusion evidence for aeolian input or hydrothermal origin of I-S at either deposit. The I-S formed exclusively at the expense of volcanic glass and not from K-feldspar. Residual quartz phenocrysts in the clays still preserve primary glassy silicate melt inclusions and lack secondary aqueous fluid inclusion trails. The dD and δ18O values of kaolinite and I-S are suggestive of low formation temperatures (<40ºC). Rb-Sr and K-Ar dating of I-S-bearing clay separates yield Lower Cretaceous ages at Seilitz and indicates the presence of excess or inherited 40Ar in illite-rich I-S. In contrast, Triassic to Jurassic Rb-Sr ages are obtained for I-S from the Kemmlitz kaolin deposit.

Giant quartz vein formation and high-elevation meteoric fluid infiltration into the South Armorican Shear Zone: geological, fluid inclusion and stable isotope evidence

2012 ◽  
Vol 169 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Jérémie Lemarchand ◽  
Philippe Boulvais ◽  
Martin Gaboriau ◽  
Marie-Christine Boiron ◽  
Romain Tartèse ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Fluid Inclusion ◽  
Shear Zone ◽  
Quartz Vein ◽  
High Elevation ◽  
The South ◽  
Vein Formation ◽  
Fluid Infiltration ◽  
Isotope Evidence

Chronology and orientation of N2–CH4, CO2-H2O, and H2O-rich fluid-inclusion trails in intrametamorphic quartz veins from the Cuiabá gold district, Brazil

1990 ◽  
Vol 54 (375) ◽  
pp. 245-255 ◽  
Author(s):  
C. J. S. de Alvarenga ◽  
M. Cathelineau ◽  
J. Dubessy
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Low Grade ◽  
Fluid Circulation ◽  
Raman Spectrometry ◽  
Mato Grosso ◽  
Spectrometry Analysis ◽  
Quartz Veins ◽  
Three Generations ◽  
Inclusion Trails

AbstractThe upper Proterozoic Cuiabá group of Mato Grosso, Brazil, is composed of low-grade clastic meta-sediments which have been folded by several successive tectonic events. Three generations of quartz veins are associated with the structural evolution of this area. The first veins are deformed by the main tectonic phases and show a complex deformational patterns. The second set is parallel to the cleavage and was formed syntectonically during the main folding phase, whilst the last quartz veins are related to a later stage of deformation. A systematic study of fluid inclusions in relation with a statistical study of microstructural markers (fluid inclusion trails, opened microcracks) was carried out on quartz veins from three localities. On the basis of microthermometric studies and Raman spectrometry analysis, four differents types of fluids have been distinguished, each trapped in specific fluid inclusion trails: (i) CO2-rich liquids and vapours (Lc, Vc) at Casa de Pedra, (ii) Lc and Vc inclusions with variable amounts of CO2, CH4, N2 in the vapour phase at BR-70, (iii) CH2-N2-rich vapours (Vn-m), and (iv) aqueous inclusions (L) with variable salinities representing the last fluid generations at all localities.At Casa de Pedra and BR-70, most fluids are observed within the three generations of quartz veins, indicating an important fluid circulation associated with the last phase of brittle deformation. Fluid inclusions of type (iii) and (iv) are oriented along several well defined directions. The study shows the importance of integrated microstructural and fluid-inclusion studies for understanding the geometry and chronology of fluid circulation.

scholarly journals Emeralds from the Delbegetey deposit (Kazakhstan): mineralogical characteristics and fluid-inclusion study

2006 ◽  
Vol 70 (2) ◽  
pp. 159-173 ◽  
Author(s):  
E.V. Gavrilenko ◽  
B. Calvo Pérez ◽  
R. Castroviejo Bolibar ◽  
D. García del Amo
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Isotope Composition ◽  
Aqueous Fluid ◽  
Fluid Inclusion Study ◽  
Refractive Indices ◽  
Mineralogical Characteristics ◽  
Primary Fluid ◽  
Inclusion Study ◽  
Characteristic Features

AbstractThe aim of this study is to provide the first detailed mineralogical and fluid-inclusion description of emeralds from the Delbegetey deposit (Kazakhstan). The characteristic features of Delbegetey emeralds are established: they have dissolution figures on crystal faces, bluish colour and distinct colour zoning; the refractive indices are ω = 1.566–1.570, ε = 1.558–1.562, and the specific gravity is 2.65±0.005, relatively low for natural emeralds; they have very small concentrations of the impurities (Fe, Mg, Na and others) typical of other emeralds, and contain Cr and V; there is a significant preponderance of vapour in fluid inclusions of all types and there is liquid-to-vapour homogenization of primary fluid inclusions (at 395–420°C). The lattice oxygen isotope composition data obtained (δ18O SMOW value of 11.3%o) situate the deposit within the range characteristic of other granite-related emerald deposits. Emerald crystallization took place in low-density (0.40–0.55 g/cm3) aqueous fluid, with the following chemical composition (mol.%): 75.6-97.4 H2O, 0.0-18.4 CO2, 0.0-0.9 CH4, and 4.06-9.65 wt.% NaCl equiv. salinity. According to the calculated isochores, the pressure of formation of the Delbegetey emeralds can be estimated at 570–1240 bar.

Fluid inclusion and thermobarometric study of interaction between mafic xenoliths and plagiogranites in the Lotta River Area, Lapland Granulite Belt

2020 ◽  
Author(s):  
Valentina Butvina ◽  
Maria Golunova ◽  
Oleg Safonov
Keyword(s):  
Carbon Dioxide ◽  
Fluid Inclusion ◽  
Aqueous Fluid ◽  
Coarse Grained ◽  
Granulite Metamorphism ◽  
Granulite Belt ◽  
Lapland Granulite Belt ◽  
Compositional Variations ◽  
Granulite Xenoliths ◽  
Subordinate Amount

&lt;p&gt;Thermobarometric data and fluid inclusions data of conditions of interaction between mafic granulite xenoliths and plagiogranites in the Lotta river area, Lapland Granulite Belt, confirm the conclusion that leucocratic garnet-bearing plagiogranites of the Lapland complex are associated with the anatexis of country khondalites during peak of metamorphism.&lt;/p&gt;&lt;p&gt;The formation of plagiogranitic magmas, probably, occurred at depths of about 25-30 km. As they ascended, they captured numerous xenoliths (Kozlov, Kozlova, 1998). The most remarkable of them are two-pyroxene-plagioclase granulite xenoliths (orthopyroxene &amp;#177; clinopyroxene + plagioclase &amp;#177; quartz + magnetite + ilmenite + pyrrhotite). The xenoliths show extensive amphibole formation, which is manifested as coronas of K-bearing pargasite-edenite amphibole and coarse-grained amphibole-quartz symplectites in contacts of pyroxenes, magnetite, ilmenite and pyrrhotite with plagioclase.&lt;/p&gt;&lt;p&gt;The more calcic composition of plagioclase and the lower Mg-number of pyroxenes in the amphibolized portions of xenoliths correspond to the amphibole formation via reaction: Opx + Ilm + Mt + Pl = Amph &amp;#177; Qtz. Amphibole formation is locally accompanied by biotite, indicating the addition of potassium into the xenoliths.&lt;/p&gt;&lt;p&gt;A pressure of 6.0-6.4 kbar was estimated from the equilibrium of clinopyroxene + orthopyroxene + plagioclase + quartz in non-amphibolized portions of xenoliths. The corresponding temperatures 800-860&amp;#176;C are within the range of temperatures estimated for the plagiogranite crystallization (Kaulina et al., 2014) as well as peak temperatures of the M2 tectonic-thermal event in the Lapland complex (Mints et al., 2007). Amphibole-plagioclase equilibrium (Blundy, Holland, 1990) recorded the temperatures of the amphibole formation 740-780&amp;#176;C at a pressure of 5.0-5.5 kbar. Compositional variations of amphibole toward tremolite indicate further cooling. It was, probably, due to the interaction of an essentially aqueous fluid issued from plagiogranitic magma with xenoliths as they were captured and transported.&lt;/p&gt;&lt;p&gt;Indeed, xenoliths are crossed by plagiogranitic veins. Abundance of aqueous-salt (17-20 wt. % NaCl eq.) inclusions and the subordinate amount of carbon dioxide inclusions in plagiogranite minerals confirm this assumption. Thus, plagiogranites of the Lapland complex and associated fluids were formed inside the complex at P-T parameters comparable to the peak conditions of granulite metamorphism. During ascension, these granite magmas could only produce fluid effects on the country rocks including xenoliths.&lt;/p&gt;

A petrological and fluid inclusion study of calc-silicate–charnockite associations from southern Kerala, India: implications for CO2 influx

1998 ◽  
Vol 135 (1) ◽  
pp. 27-45 ◽  
Author(s):  
M. SATISH-KUMAR ◽  
M. SANTOSH
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusion Study ◽  
Infiltration Model ◽  
Fluid Infiltration ◽  
Carbonic Fluid ◽  
Inclusion Study ◽  
Peak Metamorphism ◽  
Isothermal Decompression ◽  
Kerala Khondalite Belt ◽  
Khondalite Belt

Recent discovery of wollastonite-bearing calc-silicate assemblages adjacent to gneiss–charnockite horizons in the supracrustal terrain of the Kerala Khondalite Belt, southern India, provides an opportunity to evaluate the carbonic fluid infiltration model proposed for charnockite formation. Petrological and fluid inclusion studies across these horizons in three representative localities are presented in this study. The calc-silicate assemblages define peak metamorphic conditions of ∼800°C at 5 kbar and define a low aCO2. Adjacent charnockite assemblages developed through dehydration involving the breakdown of garnet, biotite and quartz to produce orthopyroxene under low aH2O conditions. Retrograde reactions preserved in the calc-silicate rocks, such as scapolite–quartz symplectites, and the partial breakdown of wollastonite previously has been attributed to a near isothermal decompression during which infiltration of CO2-rich fluids occurred. Fluid inclusion studies indicate that the earliest generation of fluids preserved in the calc-silicate assemblages are aqueous (with salinity ∼8 wt% NaCl equivalent), consistent with mineral phase equilibria defining low aCO2. The estimation of NaCl content in brines coexisting with scapolite, based on the Cl content of the scapolite, indicates the presence of up to 20 wt % NaCl during the formation of scapolite consistent with the saline primary fluid inclusions. Primary carbonic inclusions occur within the retrogressed calcite+quartz assemblage after wollastonite, and are considered to represent the post-peak metamorphic carbonic fluid infiltration event, synchronous with the development of charnockites in the adjacent gneisses. These inclusions have identical characteristics to those in the charnockites. We envisage that the Kerala Khondalite Belt fluid regime was largely internally buffered during the prograde path, and that CO2 infiltration post-dated peak metamorphism. Influx of CO2 was mostly structurally controlled, and occurred along a near-isothermal uplift path. Graphite-bearing pegmatitic dykes with abundant CO2-rich inclusions in these localities attest to the transfer of carbonic fluids through magmatic conduits.

Late-kinematic gold mineralisation during regional uplift and the role of nitrogen: an example from the La Codosera area, W. Spain

1993 ◽  
Vol 57 (388) ◽  
pp. 437-450 ◽  
Author(s):  
S. J. Dee ◽  
S. Roberts
Keyword(s):  
Fluid Inclusion ◽  
Aqueous Fluid ◽  
Ductile Deformation ◽  
Ammonium Ion ◽  
Rock Interaction ◽  
Fluid Inclusion Data ◽  
Quartz Veins ◽  
Vein Formation ◽  
Peak Metamorphism ◽  
Lowermost Part

AbstractVein formation occurred throughout a deformation sequence which involved early transpressive ductile deformation through to late-kinematic transpressive brittle structures which host a series of gold prospects. Fluid inclusion data from (S1) fabric parallel veins associated with early deformation suggest that a low-salinity aqueous fluid, with a mean salinity of 6.4 wt.%, was present during peak metamorphism, Pelite mineralogy and isochores constrain peak metamorphism to the lowermost part of the upper greenschist facies at 325 to 425°C and 1.4 to 3.4 kbar.Fluid inclusion data from auriferous and barren late-kinematic quartz veins, both containing unmixing assemblages of aqueo-carbonic inclusions with low salinities of ≈2.7 wt.% NaCl equiv., indicate unmixing occurred at 300°C and 1.5 kbar.Volatiles (CO2, N2, CH4) are observed in all the late-kinematic veins. The N2contents of veins with elevated gold grades are typically higher than those with low gold grades. N2reaches 8.7 mole% in a vein with 0.49−4.6 p.p.m. Au compared to <1 mole% in a vein with <0.05 p.p.m. Au. The CH4content of late kinematic veins is generally less than 1 mole% and shows no relative enrichment in mineralised veins. The generation of N2in the mineralising fluid most likely results from interaction of fluid with the ammonium ion, NH4+, in micas and feldspars. This interaction could take place either at source, due to metamorphic devolatisation reactions, or along those structures which acted as fluid conduits due to fluid-rock interaction.

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