Speleothem water content as a proxy for past moisture variability in stalagmites from Milandre Cave, Switzerland

2020 ◽  
Author(s):  
Stéphane Affolter ◽  
Dominik Fleitmann ◽  
Anamaria Häuselmann ◽  
Markus Leuenberger
Keyword(s):  
Fluid Inclusion ◽  
Water Content ◽  
Central Europe ◽  
Fluid Inclusions ◽  
Quantitative Estimation ◽  
Isotope Analysis ◽  
Water Isotopes ◽  
The University ◽  
Nw Switzerland ◽  
Moisture Variability

<p>Speleothems are powerful archives able to gain relevant paleoclimate information on temperature, moisture source or rainfall. Specifically, there is a need for new proxy related to past moisture availability, which would allow reconstruction especially in Europe, where such records are lacking. Among speleothem-based records, quantitative estimation of the water content (hereafter WC) remains rare as it is generally a collateral result of more challenging analyses such as isotope determinations of fluid inclusions or noble gases. Using a recently developed method to analyse speleothem fluid inclusion water isotopes (Affolter et al., 2014), we obtained a record of more than 250 WC data covering the Younger Dryas and Holocene intervals with a decadal to multi-decadal resolution measured on two Swiss stalagmites from Milandre Cave, NW Switzerland. The crushing of samples in the measuring line resulted in a mean WC of 1.9 microlitre of water per gram of crushed calcite from both stalagmites. The comparison with other paleohumidity-related indicators from central Europe suggests that the WC is related to past moisture variability. In addition, trace elements strontium (Sr) and magnesium (Mg) measurements as proxies for the water residence time and growth rate respectively are ongoing at the Department of Environmental Sciences at the University of Basel, which will further help with the interpretation of the WC. New reconstruction of past moisture variability together with speleothem fluid inclusion temperature estimates (Affolter et al., 2019) would allow a better understanding of the central European climate variability during the Holocene.</p><p>Affolter, S., Häuselmann, A., Fleitmann, D., Edwards, R. L., Cheng, H., and Leuenberger, M.: Central Europe temperature constrained by speleothem fluid inclusion water isotopes over the past 14,000 years, Sci Adv, 5, eaav3809, 10.1126/sciadv.aav3809, 2019.</p><p>Affolter, S., Fleitmann, D., and Leuenberger, M.: New online method for water isotope analysis of speleothem fluid inclusions using laser absorption spectroscopy (WS-CRDS), Clim Past, 10, 1291-1304, DOI 10.5194/cp-10-1291-2014, 2014.</p>

scholarly journals Synchrotron FTIR imaging of OH in quartz mylonites

Solid Earth ◽  
2017 ◽  
Vol 8 (5) ◽  
pp. 1025-1045 ◽  
Author(s):  
Andreas K. Kronenberg ◽  
Hasnor F. B. Hasnan ◽  
Caleb W. Holyoke III ◽  
Richard D. Law ◽  
Zhenxian Liu ◽  
...  
Keyword(s):  
Water Content ◽  
Point Defects ◽  
Fluid Inclusions ◽  
Hanging Wall ◽  
Molecular Water ◽  
Main Central Thrust ◽  
Absorption Bands ◽  
Uniform Equilibrium ◽  
Quartz Grains ◽  
Water Contents

Abstract. Previous measurements of water in deformed quartzites using conventional Fourier transform infrared spectroscopy (FTIR) instruments have shown that water contents of larger grains vary from one grain to another. However, the non-equilibrium variations in water content between neighboring grains and within quartz grains cannot be interrogated further without greater measurement resolution, nor can water contents be measured in finely recrystallized grains without including absorption bands due to fluid inclusions, films, and secondary minerals at grain boundaries.Synchrotron infrared (IR) radiation coupled to a FTIR spectrometer has allowed us to distinguish and measure OH bands due to fluid inclusions, hydrogen point defects, and secondary hydrous mineral inclusions through an aperture of 10 µm for specimens > 40 µm thick. Doubly polished infrared (IR) plates can be prepared with thicknesses down to 4–8 µm, but measurement of small OH bands is currently limited by strong interference fringes for samples < 25 µm thick, precluding measurements of water within individual, finely recrystallized grains. By translating specimens under the 10 µm IR beam by steps of 10 to 50 µm, using a software-controlled x − y stage, spectra have been collected over specimen areas of nearly 4.5 mm2. This technique allowed us to separate and quantify broad OH bands due to fluid inclusions in quartz and OH bands due to micas and map their distributions in quartzites from the Moine Thrust (Scotland) and Main Central Thrust (Himalayas).Mylonitic quartzites deformed under greenschist facies conditions in the footwall to the Moine Thrust (MT) exhibit a large and variable 3400 cm−1 OH absorption band due to molecular water, and maps of water content corresponding to fluid inclusions show that inclusion densities correlate with deformation and recrystallization microstructures. Quartz grains of mylonitic orthogneisses and paragneisses deformed under amphibolite conditions in the hanging wall to the Main Central Thrust (MCT) exhibit smaller broad OH bands, and spectra are dominated by sharp bands at 3595 to 3379 cm−1 due to hydrogen point defects that appear to have uniform, equilibrium concentrations in the driest samples. The broad OH band at 3400 cm−1 in these rocks is much less common. The variable water concentrations of MT quartzites and lack of detectable water in highly sheared MCT mylonites challenge our understanding of quartz rheology. However, where water absorption bands can be detected and compared with deformation microstructures, OH concentration maps provide information on the histories of deformation and recovery, evidence for the introduction and loss of fluid inclusions, and water weakening processes.

Formation of emeralds at pegmatite-ultramafic contacts based on fluid inclusions in Kianjavato emerald, Mananjary deposits, Madagascar

2006 ◽  
Vol 70 (2) ◽  
pp. 141-158 ◽  
Author(s):  
Ye. Vapnik ◽  
I. Moroz ◽  
M. Roth ◽  
I. Eliezri
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
East Coast ◽  
Fluid Inclusion Data ◽  
Pan African ◽  
Probe Analysis ◽  
Raman Probe

AbstractKianjavato emerald (Mananjary deposits, East coast of Madagascar) was formed during metasomatic processes at the contact between pegmatites and hornblendites. The metasomatic exchange was related to a Pan-African tectonometamorphic event.Fluid inclusions in the Kianjavato emerald and quartz were studied by means of microthermometry and Raman probe analysis. Three main types of inclusions were revealed: CO2-rich, CH4-rich and aqueous-rich, with a salinity of ∼2 wt.% NaCl equiv. The inclusions occurred along the same primary and pseudosecondary trails and were considered to be formed simultaneously. Based on fluid-inclusion data, the conditions of emerald growth were 250°C < T < 450°C and P = 1.5 kbar.The fluid inclusion data for Kianjavato emerald were compared to the data for another Madagascar emerald, Ianapera. The latter is of similar age, but its genesis was determined by a shearing event. Our fluid inclusion data suggested that shearing was also important as a mechanism of introducing CO2-rich fluid for the genesis of the Kianjavato emerald.

scholarly journals Fluid Evolution of Fuzishan Skarn Cu-Mo Deposit from the Edong District in the Middle-Lower Yangtze River Metallogenic Belt of China: Evidence from Petrography, Mineral Assemblages, and Fluid Inclusions

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-25
Author(s):  
Lu Zhang ◽  
Shao-Yong Jiang ◽  
Suo-Fei Xiong ◽  
Deng-Fei Duan
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Yangtze River ◽  
Homogenization Temperature ◽  
Lithostatic Pressure ◽  
Lower Permian ◽  
Fluid Evolution ◽  
Metallogenic Belt ◽  
Lower Yangtze ◽  
Vapor Liquid

The Fuzishan Cu-Mo deposit is located in the Edong district of the Middle-Lower Yangtze River Metallogenic Belt, China. The orebodies mainly occurred as lenticular and bedded shapes in the skarn zone between the Lower Permian Qixia Formation carbonate rocks and the quartz diorite. Four paragenetic stages have been recognized based on petrographic observations: (1) prograde skarn stage, (2) retrograde skarn stage, (3) quartz-sulfide stage, and (4) carbonate stage. Six fluid inclusion types were recognized: S1(vapor + liquid + halite ± other daughter minerals), S2(vapor + liquid + daughter minerals except halite), LV(rich liquid + vapor), VL(rich vapor + liquid), V (vapor), and L (liquid) types. Fluid inclusion studies show distinct variations in composition, final homogenization temperature, and salinity in four stages. Daughter minerals of the primary fluid inclusions include chalcopyrite, molybdenite, hematite, anhydrite, calcite, and halite in the prograde skarn stage and hematite, calcite, and sulfide (?) in the retrograde skarn stage. No daughter minerals occurred in the quartz-sulfide and carbonate stages. Final homogenization temperatures recorded in these stages are from 405 to >550°C, from 212 to 498°C, from 150 to 485°C, and from 89 to 223°C, respectively, while salinities are from 3.7 to 42.5, from 2.6 to 18.5, from 2.2 to 17.9, and from 0.2 to 11.5 wt.% NaCl equivalent, respectively. The coexisting VLand S1type fluid inclusions show similar homogenization temperature of 550 to about 650°C in the prograde skarn stage, indicating that immiscibility occurred at lithostatic pressure of 700 bars to perhaps 1000 bars, corresponding to a depth of 2.6 km to about 3.7 km. The coeval VLand LVtypes fluid inclusions with homogenization temperature of 350 to 400°C in the late retrograde skarn and quartz-sulfide stages suggest that boiling occurred under hydrostatic pressure of 150 to 280 bars, equivalent to a depth of 1.5 to 2.8 km. Mo mineralization in the retrograde stage predated Cu mineralization which mainly occurred in the quartz-sulfide stage. Fluid compositions indicate that ore-forming fluid has highfO2and rich Cu and Mo concentration in the early stage, while relatively lowerfO2and poor Cu and Mo concentration in the middle to late stages. Microthermometric data show a decreasing trend in temperature and salinity in the fluid evolution process. Decreasing temperature and boiling event may be the main factors that control the ore precipitation.

scholarly journals Mineralogical and Fluid Inclusions Study of Epithermal Type Veins Intruding the Volcanic Rocks of the Kornofolia Area, Evros, NE Greece.

2019 ◽  
Vol 55 (1) ◽  
pp. 202
Author(s):  
Foteini Aravani ◽  
Lambrini Papadopoulou ◽  
Vasileios Melfos ◽  
Triantafillos Soldatos ◽  
Triantafillia Zorba ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fluid Inclusion ◽  
Hydrothermal Alteration ◽  
Fluid Inclusions ◽  
Volcanic Rocks ◽  
The Other ◽  
Calc Alkaline ◽  
Ft Ir ◽  
Host Rocks

The volcanic rocks of Kornofolia area, Evros, host a number of epithermal-type veins. The host rocks are Oligocene calc-alkaline andesites to rhyo-dacites. The andesites form hydrothermal breccias and show hydrothermal alteration. The veins comprise mainly silica polymorphs such as quartz, chalcedony and three types of opal (milky white, transparent and green). Amethyst also forms in veins at the same area. Apart from the silica polymorphs, the veins are accompanied by calcite and zeolites. The main aim of this study is the characterization of the silica polymorphs. Using FT-IR analyses, variations in the crystal structure of the three opals were recognized. The green opal is found to be more amorphous than the other two types. Fluid-inclusion measurements were performed in calcite and were compared with amethyst from previous studies. The Th is between 121-175 °C and the Te between -22.9 and -22.4 °C. The salinities range from 0.9 to 4.5 wt % NaCl equiv.

scholarly journals Technical Note: Noble gas extraction procedure and performance of the Cologne Helix MC Plus multi-collector noble gas mass spectrometer for cosmogenic neon isotope analysis

2021 ◽  
Author(s):  
Benedikt Ritter ◽  
Andreas Vogt ◽  
Tibor J. Dunai
Keyword(s):  
Mass Spectrometer ◽  
Noble Gas ◽  
Primary Standard ◽  
Isotope Analysis ◽  
Extraction Procedure ◽  
Technical Note ◽  
High Mass ◽  
Experimental Setup ◽  
And Performance ◽  
The University

Abstract. We established a new laboratory for noble gas mass spectrometry that is dedicated for the development and application to cosmogenic nuclides at the University of Cologne (Germany). At the core of the laboratory are a state-of-the-art high mass resolution multicollector Helix MCPlus (Thermo-Fisher) noble gas mass spectrometer and a novel custom-designed automated extraction line. The Mass-spectrometer is equipped with five combined Faraday Multiplier collectors, with 1012 Ω and 1013 Ω pre-amplifiers for faraday collectors. We describe the extraction line and the automized operation procedure for cosmogenic neon and the current performance of the experimental setup. Performance tests were conducted using gas of atmospheric isotopic composition (our primary standard gas); as well as CREU-1 intercomparison material, containing a mixture of neon of atmospheric and cosmogenic composition. We use the results from repeated analysis of CREU-1 to assess the performance of the current experimental setup at Cologne. The precision in determining the abundance of cosmogenic 21Ne is equal or better than those reported for other laboratories. The absolute value we obtain for the concentration of cosmogenic 21Ne in CREU is indistinguishable from the published value.

A new occurrence of lazulite from the Main Central Thrust in Kumaun Himalaya, India: fluid inclusion, EPMA and Raman spectroscopy focusing on lazulite in a highly tectonized zone

2019 ◽  
Vol 481 (1) ◽  
pp. 211-230 ◽  
Author(s):  
Dinesh S. Chauhan ◽  
Rajesh Sharma ◽  
D. R. Rao
Keyword(s):  
Raman Spectroscopy ◽  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Structural Formula ◽  
Stability Field ◽  
Adjacent Area ◽  
Structural Level ◽  
Main Central Thrust ◽  
Kumaun Himalaya ◽  
D Values

AbstractThe present study reports and investigates ‘lazulite’ occurring in the vicinity of a highly tectonized zone of the Main Central Thrust (MCT) in the Himalaya. The azure blue lazulite, hosted in quartz veins, occurs in fractured Berinag quartzite, which forms the footwall of the MCT near Sobla village in NE Kumaun Himalaya, India. Lazulite was investigated using SEM-EDX, micro Raman spectroscopy, fluid inclusion microthermometry and electron probe microanalysis (EPMA). Lazulite contains inclusions of rutile and hematite and has Mg/(Mg+Fe) ratios of 0.86 to 0.90. The phosphorus in lazulite shows a negative trend with Mg+Al contents. This lazulite is an intermediate solid solution near the lazulite end-member with a cationic composition in the structural formula: Mg0.81–0.89Fe0.10–0.13 Al1.88–1.98P2.00–2.07. Its composition in the lazulite–scorzalite stability field points to a higher temperature of its formation. Fluids trapped as inclusions in lazulite and the associated quartz are generally C–O–H fluid. The fluid inclusion isochors for lazulite, together with the temperature calculated for metamorphism of the equivalent structural level in the adjacent area suggest 500–600°C and 7.25 to 9.25 kbar, which match the peak metamorphic temperature–pressure derived elsewhere for the Higher Himalayan Crystallines. Moderately enriched δD‰ values and H2O–CO2–low NaCl fluid suggest that water from a deep reservoir, more likely a metamorphic fluid, participated in lazulite formation. Classic sigmoidal fluid inclusions in lazulite reveal their development during MCT shearing, whereas the overpressured fluid inclusions suggest a post-lazulite uplift. The MCT lazulite is interpreted to have formed during Himalayan shearing and concurrent metamorphism. The present study also implies that this refractory mineral can sustain fluid inclusions within it against intense deformation conditions, such as in the MCT.

‘Buried Landscapes’ in Southern Italy

Antiquity ◽  
1949 ◽  
Vol 23 (90) ◽  
pp. 58-72 ◽  
Author(s):  
John Bradford
Keyword(s):  
Central Europe ◽  
Air Force ◽  
Southern Italy ◽  
Archaeological Sites ◽  
Royal Air Force ◽  
University Of Oxford ◽  
Association Meeting ◽  
The University ◽  
Capital Value ◽  
Dense Concentration

It is widely known that war-time air photography has led to the discovery of many new archaeological sites of importance in Mediterranean lands. Many hundreds of tumuli have been added to the list, at such famous Etruscan cemeteries as Cerveteri and Tarquinia and complete systems of Roman land-partition by Centuriation have been identified round the coloniae of Iader and Salonae, on the shores of Dalmatia. But by far the most notable discoveries of all are those on the Foggia Plain, in the Province of Apulia, in Southeast Italy. Great numbers of Prehistoric, Roman, and Medieval sites are being identified, and some preliminary results have already been published in ANTIQUITY(' Siticulosa Apulia ', December 1946). Select examples were exhibited at the Classical Conference at Oxford and at the British Association Meeting, in 1948, and again for several months this year, in the Ashmolean Museum. These were chosen from a number which it was fortunately possible to acquire for the University of Oxford, now housed at the Pitt Rivers Museum, where they are being studied in detail. This collection was based on vertical photographs taken by the Royal Air Force, and oblique photographs taken by Major Williams-Hunt and myself (which were the first to reveal this dense concentration of sites, spread more thickly on the ground than almost anywhere else in Europe). This heavy concentration is of much more than local importance. During the last few years I have examined many thousands of air photographs of Southern and Central Europe taken at various seasons, in the course of my research. While these provide much interesting data and give us, as it were, an illustrated ' Domesday ' survey of Europe in the middle of the 20th century (of capital value to Anthropology), in no other area has there as yet been anything approaching the quantity of crop-marks, grass-marks, soil-marks and earthworks which have come to light in Apulia. There are various reasons for this and a detailed account must await a later report. For our present purposes, it will be enough to single out one or two areas, for comparison.

Comparison of fluid processes in coexisting wolframite and quartz from a giant vein-type tungsten deposit, South China: Insights from detailed petrography and LA-ICP-MS analysis of fluid inclusions

2019 ◽  
Vol 104 (8) ◽  
pp. 1092-1116 ◽  
Author(s):  
Jun-Yi Pan ◽  
Pei Ni ◽  
Ru-Cheng Wang
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
South China ◽  
Inductively Coupled Plasma ◽  
Fluid Phase ◽  
Fluid Temperature ◽  
Depositional Sequence ◽  
Ms Analysis ◽  
Icp Ms ◽  
Tungsten Mineralization

Abstract Granite-related wolframite-quartz veins are the world's most important tungsten mineralization and production resource. Recent progress in revealing their hydrothermal processes has been greatly facilitated by the use of infrared microscopy and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis of both quartz- and wolframite-hosted fluid inclusions. However, owing to the paucity of detailed petrography, previous fluid inclusion studies on coexisting wolframite and quartz are associated with a certain degree of ambiguity. To better understand the fluid processes forming these two minerals, free-grown crystals of intergrown wolframite and quartz from the giant Yaogangxian W deposit in South China were studied using integrated in situ analytical methods including cathodoluminescence (CL) imaging, infrared microthermometry, Raman microspectroscopy, and fluid inclusion LA-ICP-MS analysis. Detailed crystal-scale petrography with critical help from CL imaging shows repetition of quartz, wolframite, and muscovite in the depositional sequence, which comprises a paragenesis far more complex than previous comparable studies. The reconstruction of fluid history in coexisting wolframite and quartz recognizes at least four successive fluid inclusion generations, two of which were entrapped concurrently with wolframite deposition. Fluctuations of fluid temperature and salinity during precipitation of coexisting wolframite and quartz are reflected by our microthermometry results, according to which wolframite-hosted fluid inclusions do not display higher homogenization temperature or salinity than those in quartz. However, LA-ICP-MS analysis shows that both primary fluid inclusions in wolframite and quartz-hosted fluid inclusions associated intimately with wolframite deposition are characterized by strong enrichment in Sr and depletion in B and As compared to quartz-hosted fluid inclusions that are not associated with wolframite deposition. The chemical similarity between the two fluid inclusion generations associated with wolframite deposition implies episodic tungsten mineralization derived from fluids exhibiting distinct chemical signatures. Multiple chemical criteria including incompatible elements and Br/Cl ratios of fluid inclusions in both minerals suggest a magmatic-sourced fluid with the possible addition of sedimentary and meteoric water. Combined with microthermometry and Raman results, fluid chemical evolution in terms of B, As, S, Sr, W, Mn, Fe, and carbonic volatiles collectively imply fluid phase separation and mixing with sedimentary fluid may have played important roles in wolframite deposition, whereas fluid cooling and addition of Fe and Mn do not appear to be the major driving factor. This study also shows that fluid inclusions in both wolframite and coexisting quartz may contain a substantial amount of carbonic volatiles (CO2 ± CH4) and H3BO3. Ignoring the occurrence of these components can result in significant overestimation of apparent salinity and miscalculation of LA-ICP-MS elemental concentrations. We suggest that these effects should be considered critically to avoid misinterpretation of fluid inclusion data, especially for granite-related tungsten-tin deposits.

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