liquid absent aqueous fluid inclusions and phase equilibria in the system cacl2naclh2o abstract raman spectra and microthermometric data are reported for a new class of aqueous fluid inclusions in quartz from the bushveld complex the inclusions which are approximated by the system cacl2 nacl h2o hold special interest because they display the following properties 1 1 the inclusions do not contain a liquid phase at room temperature but they homogenize to an aqueous liquid at elevated temperatures 2 2 initial melting occurs at a reaction point at 29 c rather than at the cacl2 nacl h2o eutectic point at 52 c as is generally the case for fluid inclusions approximated by this system 3 3 ice is absent in the subsolidus assemblage despite the high h2o contents of the inclusions an aqueous liquid is generated upon heating through decomposition of incongruently melting hydrate daughter minerals 4 4 the most abundant minerals in the subsolidus assemblages are antarcticite cacl2 6h2o and a second hydrate that may be a new mineral probably a polymorph of cacl2 4h2o and 5 5 the fluid compositions fall outside the compositional limits defined by previous studies of natural fluid inclusions the inclusions are characterized by a high ca na ratio and a very high concentration of total dissolved solids greater than 52 wt aqueous fluid inclusions that do not contain a liquid phase at ambient temperature may be commonly overlooked or misinterpreted as mineral inclusions the liquid absent aqueous inclusions from the bushveld complex are spatially associated with a second type of fluid inclusion comprised of antarcticite halite vapor and liquid at 20 c the two types of inclusions have similar bulk compositions but they differ radically in melting behavior because their compositions lie on opposite sides of a subsolidus join given the topology of the cacl2 nacl h2o phase diagram small variations in bulk composition in the vicinity of a phase boundary or subsolidus join can result in large differences in the initial melting temperature equilibrium melting sequence and phase proportions at 20 c conversely significant constraints on fluid composition may be derived from qualitative observations of the equilibrium melting sequence

a study of soil water movement combining soil water potential with stable isotopes at two sites of shallow groundwater areas in the north china plain in the shallow groundwater areas of the north china plain ncp precipitation infiltration and evapotranspiration in the vertical direction are the main processes of the water cycle in which the unsaturated zone plays an important role in the transformation process between precipitation and groundwater in this paper two typical sites in cangzhou cz and hengshui hs of hebei province with shallow water tables were selected to analyse the relationship among precipitation soil water and groundwater at each site precipitation soil water at depths 10 20 30 50 70 100 150 200 300 cm and groundwater were sampled to analyse the stable isotope compositions of hydrogen and oxygen the soil water potentials at the corresponding depths were observed although the climates at the two sites are similar there are some differences in the infiltration process soil water movement and groundwater recharge sources evaporation occurred at the upper depths which led to the decrease of soil potential and the enrichment of heavy isotopes at the cz site precipitation infiltrated with piston mode and an obvious mixture effect existed during the infiltration process preferential flow may exist in the soil above 100 cm depth however at the hs site soil water moved in piston mode and groundwater was mainly recharged by precipitation when precipitation recharged the groundwater it experienced a strong evaporation effect the results of the soil water movement mechanism provides the transformation relationship among precipitation soil water and groundwater in the middle and eastern ncp copyright 2009 john wiley sons ltd

the variety of lithologies in the yamato 86032 lunar meteorite implications for formation processes of the lunar crust abstract we performed a petrologic mineralogical geochemical and isotopic study of several lithologies in the y 86032 feldspathic breccia this study leads us to conclude that y 86032 likely originated on the lunar farside y 86032 is composed of several types of feldspathic clasts granulitic breccias and minor basaltic clasts set in a clastic matrix we identify an an97 anorthosite that has an contents similar to those of nearside fans mg molar mg mg fe 100 values vary significantly from 45 to 80 covering the ranges of both nearside fans and the mg gap between fans and the mg suite a light gray feldspathic lg breccia making up 20 of the investigated slab 5 2 3 6 cm2 mainly consists of fragments of anorthosites an93 anorthosite more sodic than nearside fans lg also contains an augite plagioclase clast which either could be genetically related to the an93 anorthosite or to slowly cooled basaltic magma intruded into the precursor rock the na rich nature of both an93 anorthosite and this clast indicates that the lg breccia was derived from a relatively na rich but incompatible element poor source the mg variation indicates that the an97 anorthosite is a genomict breccia of several types of primary anorthosites granulitic breccias in y 86032 have relatively high mg in mafic minerals the highest mg values in mafic minerals for the an97 anorthosite and granulitic breccias are similar to those of mg rich lithologies recently described in dhofar 489 basaltic clasts in the dark gray matrix are aluminous and the zoning trends of pyroxene are similar to those of vlt or lt basalts the crystallization of these basaltic clasts pre date the lithification age of the clastic matrix at 3 8 ga the low k contents of plagioclase in both the anorthositic and basaltic clasts and generally low incompatible element abundances in all the lithologies in y 86032 indicate that kreep was not involved during the formation of the precursor lithologies this observation further suggests that urkreep did not exist in the source regions of these igneous lithologies all these facts support the idea that y 86032 was derived from a region far distant from the pkt and that the lithic clasts and fragments are indigenous to that region an an97 anorthositic clast studied here has distinct sm nd isotopic systematics from those previously found for another an97 anorthositic clast and an93 anorthosite and suggests either that an97 anorthosites come from isotopically diverse sources or that the sm nd isotopic systematics of this clast were reset 4 3 ga ago these lines of geochemical isotopic and petrologic evidence suggest that the lunar crust is geochemically more heterogeneous than previously thought

an isotopic study 2h and 18o of water movements in clayey soils under a semiarid climate we applied the natural variations of stable isotopes in water to the study of infiltration in clayey soils and to the study of groundwater recharge in the small drainage basin of barogo in west africa the comparison between the variations in isotopic contents of soil water and rainwater in 1988 and 1989 led us to characterize two infiltration processes 1 an infiltration through the soil matrix of rainwater that mixed with mobile water which was held in the superficial part of the soil and was enriched in heavy isotopes by evaporation and 2 a fast and deeper infiltration by preferential flow along macropores that bypassed the superficial part of the soil the study of the variations in groundwater isotopic content led us again to separate the recharge process into two components 1 a slow infiltration through the soil matrix and the weathered basement distributed recharge and 2 a fast and direct recharge through conducting fissured zones localized recharge a schematic and local representation of groundwater recharge in the barogo basin allowed us to estimate that direct recharge represented around 70 of the total recharge in 1989

modern and long term evaporation of central andes surface waters suggests paleo archives underestimate neogene elevations abstract central andean paleoelevations reconstructed from stable isotope and paleofloral data imply a large magnitude 2 km miocene to modern surface uplift however the isotopic relationships between precipitation surface waters and soil waters upon which these reconstructions are based remain poorly constrained for both past and in many cases modern conditions we quantify the relationships between central andean precipitation and surface waters by measuring the isotopic composition of 249 stream water samples 18o and d collected between april 2009 and october 2012 the isotopic compositions of stream waters match precipitation along the eastern flank in contrast altiplano surface waters possess a lower d 18o slope 4 59 vs 8 for meteoric waters not observed in precipitation which signals heavy isotope evaporative enrichment in surface waters paleoclimate models indicate that highly evaporative conditions have persisted on the plateau throughout andean uplift and that conditions may have been more evaporative when the andes were lower thus more ancient proxy materials may have a greater evaporative bias than previously recognized and paleoelevation reconstructions from stable isotope based central andean plateau proxy materials likely overstate miocene to present surface uplift we propose altiplano paleoelevations of 1 2 km at 24 5 ma 1 5 2 9 km by 11 45 ma and modern elevations by 6 ma based on the lightest isotopic compositions observed in altiplano proxy materials which are least likely to be influenced by evaporation these constraints limit total late miocene to modern uplift to

mineralogy chemistry and fluid aided evolution of the pea ridge fe oxide y ree deposit southeast missouri usa the kiruna type pea ridge iron oxide apatite ioa deposit is hosted by a sequence of 1 47 ga rhyolite tuffs of the st francois mountains southeast missouri usa it consists of a series of altered zones composed mainly of amphibole magnetite hematite and quartz together with the presence of several rare earth element y ree rich breccia pipes in many cases the fluorapatite within these zones is rich in inclusions of monazite iron oxide and quartz inclusions plus minor xenotime monazite and minor xenotime are also found intergrown as inclusions in the fluorapatite as well as in surrounding recrystallized magnetite and hematite in the magnetite ore monazite and xenotime typically occur as inclusions within both oxides monazite ce and xenotime y are both relatively poor 2 wt in tho2 and uo2 no significant compositional differences exist in the y ree chemistry between monazite and xenotime inclusions in fluorapatite compared to grains intergrown with magnetite and hematite suggesting that these two ree rich minerals are cogenetic monazite xenotime geothermometry and geochronology of monazite inclusions in fluorapatite provide evidence that formation remobilization of the y ree phosphates took place at ca 50 to 400 c approximately 5 to 10 m y after emplacement of the main iron oxide phosphate orebody evidence from field relationships and fluid inclusion chemistry together with the massive recrystallization and remobilization of fluorapatite monazite xenotime and iron oxides at pea ridge suggest a subvolcanic origin coupled with a strong metasomatic reworking of the ioa deposit

numerical model to determine the composition of h2o nacl cacl2 fluid inclusions based on microthermometric and microanalytical data natural fluids approximated by the h2o nacl cacl2 system are common in a wide range of geologic environments including sedimentary basins associated with hydrocarbon occurrences and mvt deposits submarine hydrothermal systems and other metamorphic magmatic and hydrothermal environments we present a comprehensive numerical model and microsoft excel based computer program to determine the compositions of fluid inclusions in the h2o nacl cacl2 system based on microthermometric and microanalytical data the model consists of six polynomial correlation equations that describe liquid salinity as a function of nacl cacl2 ratio and melting temperature on each of the ice hydrohalite halite antarcticite cacl2 4h2o and cacl2 2h2o vapor saturated liquidus surfaces the cotectic and peritectic boundaries are determined from the intersections of the liquidus surfaces the model is implicitly internally consistent and topologically correct the model expands upon the compositional range of applicability and the data types that can be used for compositional determination it reproduces experimental data for all compositions that lie within the h2o nacl cacl2 4h2o compositional triangle in the h2o nacl cacl2 system and yields accurate reproductions of the h2o nacl and h2o cacl2 binaries furthermore in comparison to previously published models the one presented here eliminates systematic errors wavy isotherms and cotectic and peritectic curves with local bumps

europium mass balance in polymict samples and implications for plutonic rocks of the lunar crust abstract from correlations of sm concentration and sm eu ratio with th concentration for a large number of polymict samples from various locations in the lunar highlands and the value of 0 91 g g for the mean th concentration of the highlands surface crust obtained by the orbiting gamma ray experiments we estimate the mean concentrations of sm and eu in the lunar surface crust to be between 2 and 3 g g sm and 0 7 and 1 2 g g eu the compositional trends indicate that there is no significant enrichment or depletion of eu on the average compared to sm relative to chondritic abundances i e there is no significant eu anomaly in average upper crust although rich in plagioclase 70 the upper crust does not offer evidence for a gross vertical separation of plagioclase from the final liquid from which it crystallized this and the chondritic ratio of eu al in average highlands material imply that the net effect of the processes that led to formation of the lunar crust was to put most of the al and incompatible elements in the crust the concentration of eu in most polymict samples from the highlands exceeds that which can be supplied by the fraction of kreep necessary to supply the incompatible trace elements plus the fraction of plagioclase necessary to supply the al if the plagioclase has the composition of that in ferroan anorthosite among plutonic rocks only plagioclase in rocks from the magnesian suite can supply the excess eu in the polymict rocks owing to the intermediate value of the mean mg fe ratio of the crust a significant fraction of the mafic rocks of the lunar highlands must have lower mg fe ratios than the norites and troctolites of the magnesian suite of plutonic rocks a large fraction of the plagioclase in the lunar crust is associated not with ferroan anorthosite but with more mafic rocks e g norite anorthositic norite there is little evidence in the eu data that the lunar crust ever consisted of a thick shell of nearly pure plagioclase as envisioned in some formulations of the magma ocean model of its formation

hydrological factors in the interpretation of stable isotopic proxy data present and past a european perspective in the context of this paper stable isotopic proxies are those preserving directly or via known or calculable fractionation factors a record of 18o 16o and or 2h 1h in the water which contributed to their growth suitable proxies include amongst others tree ring cellulose bone phosphate lake sediment minerals and speleothem fluid inclusions a principal aim of studying isotopic proxies is to gain more information about past climates through a knowledge of how rainfall isotope compositions have changed over time however converting back from proxy to rainfall is not necessarily straightforward because however well the isotopic fractionation due to proxy growth or formation is understood a variety of modifying processes may have intervened between this and the actual rainfall events three main reservoirs of environmental water may contribute to the isotopic compositions of terrestrial proxy indicators surface waters soil moisture and groundwater each of these can in principle be isotopically modified compared to rainfall in the locality this review examines these effects and how they may change under different european climate types at the present day it is concluded that while groundwater isotopic compositions typically represent closely the bulk composition of rainfall under a variety of climatic regimes soil and particularly lake waters require detailed study if their isotope systematics are to be adequately understood the review also finds that to a large extent the present is the key to the past in terms of recharge processes during the late pleistocene though glaciation may have had profound isotopic consequences in certain areas while a more general aridity led to the apparent absence of recharge in most areas for much of the late devensian

combining soil water balance and clumped isotopes to understand the nature and timing of pedogenic carbonate formation abstract pedogenic carbonate is an important archive for paleoclimate paleoecology and paleoelevation studies however it can form under seasonal environmental conditions that differ significantly from the mean growing season environment or mean annual conditions potentially complicating its use for proxy reconstructions the observed seasonal temperature is typically but not always biased high relative to mean annual air temperature mat to evaluate the annual timing of pedogenic carbonate formation ten different soils were sampled across the western united states sites were selected to span a variety of precipitation regimes and soil orders precipitation regimes ranged from arid sites mean annual precipitation map 50 cm dominated by summer precipitation pedogenic carbonate formation temperatures derived from clumped isotope measurements ranged between 6 and 22 c with most samples falling at or below mat clumped isotope temperatures were compared to monthly precipitation normals and modeled monthly values of evapotranspiration and soil water content results show that carbonate formation temperatures agree with the annual timing of soil water depletion suggesting soil moisture content is a primary control on the timing of pedogenic carbonate formation although the seasonal bias is a function of environmental factors that are difficult to reconstruct in paleo studies the use of other paleosol proxies can help to assess if changes in clumped isotope temperatures are a function of changes in air temperature or hydrology these results have important implications for the production of accurate paleoclimate and paleoelevation estimates

use of δ18o tracer to identify stream and spring origins of a mountainous catchment a case study from liddar watershed western himalaya india summary water samples from precipitation streams and springs were collected and analyzed for oxygen isotope composition to identify the stream and spring origins in liddar watershed nw himalaya india samples were collected from eight precipitation sites 14 streams and six springs on bimonthly basis from january march 2008 to january 2009 the data generated indicated a strong spatial and temporal variation in oxygen isotope composition an altitude effect of 0 1 to 0 5 100 m change in elevation mean altitude effect 0 19 100 m was discernible in precipitation isotopic composition the precipitation was 18 o depleted in cooler seasons months and at higher elevations the 18 o of precipitation showed a narrow range 2 5 during the periods months of more precipitation and wide range 8 13 during the other months like precipitation the isotopic composition of streams is also controlled by the elevations of their catchments the stream water was 18 o depleted in the mountain areas with their catchments at higher altitudes than at lower elevations the streams tributaries were most 18 o depleted in may and least depleted in september the oxygen isotope composition of springs is similar to that observed in the streams being most 18 o depleted in may and least 18 o depleted in september on the basis of local vertical isotopic gradient of oxygen the mean altitude of the recharge by rainfall infiltration was estimated the widespread melting of snow the high discharges of the streams and the springs and 18 o depleted stream and spring waters indicate the dominant contribution of snow melt in may negligible snow melting precipitation in the form of snow only less stream and spring discharges and less variance indicate the contribution from baseflow in january while as exhausted snow moderate stream and spring discharges and 18 o enriched stream and spring water indicate the contribution from rainfall the best correlation was observed between the 18 o of springs and streams

late oligocene to early miocene humidity change recorded in terrestrial sequences in the ili basin south eastern kazakhstan central asia enhanced aridification of central asia driven by the combined effects of orogenic surface uplift paratethys retreat changes in atmospheric moisture transport and global cooling is one of the most prominent cenozoic climate change events of the northern hemisphere deciphering regional long term patterns of central asian hydrology is therefore a key element in understanding the role of northern hemisphere mid latitude drying in the global hydrological system this study characterizes long term palaeoenvironmental conditions between the late oligocene and early miocene in south eastern kazakhstan based on stable isotopes elemental geochemistry and laser ablation uranium lead geochronology from alluvial fluvial and pedogenic deposits sedimentary facies and geochemical weathering indices suggest an increased surface and ground water discharge fed by orographically enhanced precipitation in the tien shan hinterland in contrast pedogenic stable isotope data and elevated rates of magnesium fixation in clay minerals mirror enhanced rates of evaporation in the vadose zone due to protracted aridification this study posits that pronounced surface uplift of the tien shan mountains during the oligocene miocene transition promoted regionally increased orographic precipitation and the development of fluvial discharge systems this article is protected by copyright all rights reserved

sixth foray for pristine nonmare rocks and an assessment of the diversity of lunar anorthosites eleven nonmare samples are characterized generally both compositionally and petrographically five are almost certainly pristine ferroan anorthosite 10056c alkali anorthosite 14047c ferroan anorthosite 14312c anorthositic troctolite 14321c3 and granite 14321c4 and four are probably pristine norite 14318c noritic anorthosite 67215 quasi pristine ferroan anorthosite 73217c and norite 78527 five are unique anorthosites extending the diversity of lunar anorthosites considerably alkali anorthosites particularly 14047c are extremely rich in incompatible elements the first anorthosite from apollo 11 with manifestations of pristinity 10056c appears to be a normal member of the ferroan group however the first pristine ferroan anorthosites from apollo 14 and 17 to be studied in detail 14312c and 73217c both have unusually sodic plagioclase by ferroan standards with only 75 plagioclase 67215 is the first large 273 g probably pristine ferroan sample with less than 83 plagioclase the nature of the correlations between longitude and such parameters as eu and sm concentrations and sc sm ti sm and ca na ratios among pristine ant samples has been elucidated because five of the new pristine samples are from a western site apollo 14 interestingly ferroan anorthosite 14312c has ca na sc sm and ti sm ratios close to the normal ferroan values but significantly displaced in the direction of the nonferroan western pristine rocks this suggests that the composition longitude relationships are as old as the late stages of the crystallization of the putative magma ocean

synthetic fluid inclusions viii vapor saturated halite solubility in part of the system nacl cacl2 h2o with application to fluid inclusions from oceanic hydrothermal systems abstract halite solubility along part of the vapor saturated liquidus in the system nacl cacl 2 h 2 o has been determined using the synthetic fluid inclusion technique data allow the construction of liquidus isotherms for temperatures up to 500 c and bulk compositions containing 60 wt total salt and as much as 25 wt cacl 2 combined with previous data for the binary system nacl h 2 o and for the ternary system nacl cacl 2 h 2 o in the low salinity low temperature region a preliminary ternary phase diagram can be constructed that remains incomplete only in the cacl 2 rich region results are applied to the interpretation of saline fluid inclusions from quartz veins in oceanic metagabbros and can be applied to many other natural inclusions containing aqueous solutions with nacl and cacl 2 the dominant solutes microthermometric measurements at equilibrium of the melting temperature of ice tm ice and of the dissolution temperature of halite tm halite are sufficient to determine the bulk composition of the nacl cacl 2 h 2 o fluid

sulfate brines in fluid inclusions of hydrothermal veins compositional determinations in the system h2o na ca cl so4 sulfate is among the most abundant ions in seawater and sulfate bearing brines are common in sedimentary basins among other environments however the properties of sulfate bearing fluid inclusions during microthermometry are as yet poorly constrained restricting the interpretation of fluid inclusion compositions where sulfate is a major ion the schwarzwald mining district on the eastern shoulder of the upper rhinegraben rift is an example of a geologic system characterized by sulfate bearing brines and constraints on the anion abundances chloride versus sulfate would be desirable as a potential means to differentiate fluid sources in hydrothermal veins in these regions here we use the pitzer type formalism to calculate equilibrium conditions along the vapor saturated liquidus of the system h2o na ca cl so4 and construct phase diagrams displaying the predicted phase equilibria we combine these predicted phase relations with microthermometric and crush leach analyses of fluid inclusions from veins in the schwarzwald and upper rhinegraben to estimate the compositions of these brines in terms of bulk salinity as well as cation and anion loads sodium versus calcium and chloride versus sulfate these data indicate systematic differences in fluid compositions recorded by fluid inclusions and demonstrate the application of detailed low temperature microthermometry to determine compositions of sulfate bearing brines thus these data provide new constraints on fluid sources and paleo hydrology of these classic basin hosted ore forming systems moreover the phase diagrams presented herein can be applied directly to compositional determinations in other systems

synthetic fluid inclusions xix experimental determination of the vapor saturated liquidus of the system h2o nacl fecl2 abstract magmatic hydrothermal fluids associated with felsic to intermediate composition magmas are generally dominated by na k cl but often the fluids also contain significant concentrations of fecl 2 previously fluid inclusions containing such fluids were interpreted using the properties of h 2 o nacl because the effect of fecl 2 on the phase equilibrium and volumetric pvtx properties of aqueous fluids was essentially unknown in this study synthetic fluid inclusion experiments have been conducted to determine the vapor saturated liquidus phase relations of the system h 2 o nacl fecl 2 microthermometric and microanalytical measurements on synthetic fluid inclusions have been combined with the limited existing data as well as with predictions based on pitzer s formalism to determine the ternary cotectic and peritectic phase boundaries and liquidus fields the liquidus is qualitatively similar to those of other ternary systems of h 2 o nacl plus divalent cation chlorides mgcl 2 and cacl 2 and has been characterized through empirical equations that represent the liquid salinity on the ice and halite liquidus surfaces the ice and halite liquidi intersect at a metastable cotectic curve which can be used to determine fluid compositions in this system if metastable behavior is observed furthermore based on the experimentally determined liquidus bulk salinities of natural fluid inclusions can be determined from the last dissolution temperatures of ice and or halite using the new empirical equations

mineralogy and geochemistry of lunar meteorite queen alexandra range 93069 queen alexandra range que 93069 is a glass rich regolith breccia derived from the lunar highlands the high abundance of glassy fragments the presence of agglutinates the small size of all mineral and glass fragments the presence of mostly melt rocks and the low abundance of pristine lunar crustal rocks all indicate that que 93069 is derived from a mature regolith this conclusion is also supported by its high siderophile element content the most common mafic mineral is pyroxene with compositions that indicate derivation from ferroan ant suite rocks rare gabbro differentiation products may be indicated by the presence of silica fayalitic olivine and one pyroxferroite grain lithic fragments are mostly meta melt rocks of ant composition the glass compositions are dominated by troctolitic anorthosite compositions followed by gabbroic anorthosite and noritic anorthosite most glasses are ol normative in composition some rare basic glasses of noritic composition were observed glass fragments and matrix glasses are alkali poor except for some rare alkali rich shards the bulk chemical composition of que 93069 as well as the rare earth element ree abundance pattern is very similar to that of other highlands meteorites such as mac 88105 and y 86032 and to average lunar highlands crust one small porous clast was found to be very rich in volatile elements as well as in most lithophile and siderophile elements as this sample also contains abundant sulfides the enrichments could be related to element mobilization and redistribution by volatile sulfur species

origin of ree mineralization in the bastnas type fe ree cu mo bi au deposits bergslagen sweden the bastnas type deposits with mineral assemblages of fe oxides ca mg silicates rare earth element ree silicates ree fluorocarbonates and cu fe mo bi sulfides are associated with marble horizons in a strongly na k and or mg altered metavolcanic succession over a distance of at least 80 km in a sw ne trending zone in western bergslagen two subtypes occur 1 enriched relative to the other type in light ree lree and fe exemplified by the bastnas and rodbergsgruvan deposits and 2 enriched in heavy ree hree y mg ca and f represented by deposits in the norberg district bastnasite hosts primary fluid h2o co2 inclusions with salinities of 6 29 eq wt cacl2 and with total homogenization temperatures th tot of ca 300 400 c subtype 2 has late stage fluorite with fluid inclusions that show 1 16 eq wt nacl and th tot of ca 90 150 c molybdenite re os ages obtained from three deposits are 1 904 6 1 863 4 and 1 842 4 ma nd isotopic data from five different ree minerals yielded no defined isochron but a range in end 1 88 ga of 0 2 to 1 6 the oxygen isotope values 18osmow of dolomite and calcite from the associated ree mineralized skarn and recrystallized carbonate assemblages lie in the range 6 1 8 6 overlapping with those of the host marbles carbon isotope values 13cpdb show typical magmatic signatures of 6 7 to 4 4 while the host marbles group around ca 2 4 the sulfur isotope 34scdt values of associated sulfides range between 10 8 and 0 2 the combined evidence suggests ree mineralization beginning at 1 9 ga from mainly svecofennian juvenile magmatic 400 c fluids carrying si f cl s co2 and the ree in addition to other metals mineralization occurred through reactions with dolomitic layers in the supracrustal units coevally with regional metasomatic alteration associated with fluid circulation through an extensive active volcano plutonic complex

an assessment of the origin and variation of groundwater salinity in southeastern ghana groundwater from the major aquifers in southeastern part of ghana was sampled to determine the main controls on groundwater salinity in the area this paper uses multivariate statistical methods conventional graphical methods and stable isotope data to determine spatial relationships among groundwaters from the different hydrogeologic units in the area on the basis of salinity q mode hierarchical cluster analysis hca was used to spatially classify the samples whilst r mode factor analysis was used to reduce the dataset into two major principal components representing the sources of variation in the hydrochemistry analysis of the major chemical parameters suggests that the principal component responsible for salinity increment in the area is the weathering of minerals in the aquifers this factor is especially more significant in the upland areas away from the coast the second factor responsible for salinity in the area is the combined effects of seawater intrusion and anthropogenic activities this study finds that four major spatial groundwater groups exist in the area low salinity acidic groundwaters which are mainly derived from the birimian and togo series aquifers low salinity moderate to neutral ph groundwaters which are mainly from the voltaian buem and cape coast granitoids very high salinity waters which are not suitable for most domestic and irrigation purposes and are mainly from the keta aquifers and intermediate salinity groundwaters comprising groundwater from the keta basin aquifers with minor contributions from the other major terrains the major water type identified in this study is the ca mg hco3 type which degrades into predominantly na cl so4 more saline groundwaters toward the coast stable isotope data analyses suggest that groundwater in the voltaian aquifers is largely of recent meteoric origin the birimian and togo aquifers receive a component of recharge from the tributaries of the densu and volta rivers after the waters have undergone evaporative enrichment of the heavier isotopes in the keta basin recharge is mainly from precipitation but an observed enrichment of 2h and 18o isotopes is probably due to seawater and evaporative effects since the water table there is very shallow an analysis of the irrigation quality of groundwater from the six aquifers in the study area using sodium adsorption ratio and electrical conductivity suggests that most of the aquifers supply groundwater of acceptable quality for irrigation the only exception is the keta basin area where extremely high salinities and sar values render groundwater from this basin unsuitable for irrigation purposes

the constitution and structure of the lunar interior the current state of understanding of the lunar interior is the sum of nearly four decades of work and a range of exploration programs spanning that same time period missions of the 1960s including the rangers surveyors and lunar orbiters as well as earth based telescopic studies laid the groundwork for the apollo program and provided a basic understanding of the surface its stratigraphy and chronology through a combination of remote sensing surface exploration and sample return the apollo missions provided a general picture of the lunar interior and spawned the concept of the lunar magma ocean in particular the discovery of anorthite clasts in the returned samples led to the view that a large portion of the moon was initially molten and that crystallization of this magma ocean gave rise to mafic cumulates that make up the mantle and plagioclase flotation cumulates that make up the crust smith et al 1970 wood et al 1970 this model is now generally accepted and is the framework that unifies our knowledge of the structure and composition of the moon the intention of this chapter is to review the major advances that have been made over the past decade regarding the constitution of the moon s interior much of this new knowledge is a direct result of data acquired from the successful clementine and lunar prospector missions as well as the analysis of new lunar meteorites as will be seen results from these studies have led to many fundamental amendments to the magma ocean model much of what we know from sample analyses has been previously summarized elsewhere and only their most important aspects will be discussed in this chapter the reader is referred to the relevant chapters in the books basaltic volcanism on the terrestrial planets basaltic volcanism study project 1981 the

synthetic fluid inclusions in natural quartz i compositional types synthesized and applications to experimental geochemistry synthetic fluid inclusions having a wide range of geologically applicable compositions in the c o h s na k ca cl cu fe system have been formed by healing fractures in inclusion free natural quartz and by precipitating new quartz overgrowths on an original seed crystal inclusion types synthesized include 1 1 liquid rich pure h2o inclusions of primary and secondary origin 2 2 pure h2o inclusions with the critical density 3 3 liquid rich inclusions containing undersaturated aqueous solutions of nacl or kcl or cacl2 or mixtures of the three salts 4 4 h2o nacl inclusions containing halite daughter minerals 5 5 h2o nacl kcl inclusions containing halite and sylvite daughter minerals 6 6 h2o co2 inclusions of various compositions containing liquid h2o and either co2 vapor or co2 liquid or both at 25 c 7 7 h2o co2 nacl inclusions containing an aqueous phase liquid and vapor co2 and halite at 25 c 8 8 c o h inclusions containing liquid h2o a co2 ch4 liquid phase and graphite daughter minerals at 25 c 9 9 h2o nacl inclusions that contain a chalcopyrite daughter mineral and 10 10 inclusions representing trapping of the coexisting immiscible fluids in the h2o nacl h2o co2 nacl and na c o h systems the inclusions exhibit uniform phase ratios at room temperature and the temperatures of various phase changes within individual inclusions agree with those predicted from experimental and theoretical data indicating that the inclusion fluid has the same composition and density as the parent solution these miniature autoclaves thus may be used to study various problems related to fluid inclusion research to calibrate analytical equipment used to study natural inclusions and to study phase equilibria solubility and pvt relations of a variety of chemical systems

data model comparison of soil water δ 18 o at a temperate site in n spain with implications for interpreting speleothem δ 18 o summary an understanding of how seasonal and longer term 18 o signals in meteoric precipitation 18 o p are modified by percolation through soils is essential to link temporal changes in speleothem 18 o to surface climatic conditions this study focuses on modifications that occur in a relatively thick soil above a temperate cave site la garma n spain monthly soil water 18 o 18 o sw values at a depth of 60 cm through the year are only 14 of the range in 18 o p implying substantial homogenisation and attenuation of seasonal signals a striking feature is that 18 o sw values at 60 cm depth are lowest in summer and highest in winter the opposite anti phase to that observed in rainfall soil water residence times of up to circa 6 months in the upper 60 cm of soil and a matrix flow piston type infiltration behaviour with mixing are inferred evaporative effects on recovered soil water 18 o are minimal at this wet temperate site in contrast with published results from arid and semi arid sites a soil water model is presented to estimate monthly 18 o sw as a function of air temperature and 18 o p incorporating effects such as variations in the amount of infiltrated water changes in the ratio between evaporation and transpiration mixing with antecedent soil moisture and small enrichments in 18 o linked to evaporation and summer moisture deficits our model reproduces the observed 18 o sw results and produces 18 o outputs in excellent agreement with 18 o data for two monitored drip water sites at la garma cave that exhibit seasonal 18 o variability we conclude that simple evapotranspiration models that permit infiltration during months that have a positive hydrological balance only tend to underestimate summer rainfall contributions overall the study provides an improved framework for predicting 18 o sw trends at temperate sites such as la garma that have a relatively thick soil cover as well as for understanding seasonal ranges and trends in 18 o in cave drip sites

salt crust development in paddy fields owing to soil evaporation and drainage contribution of chloride and deuterium profile analysis summary in northeast thailand lowlands with shallow saline watertable rainfed paddy fields often present high salt concentration in the dry season forming patches or spots of salt crusts on the soil surface in this context the mechanisms implied in salt concentration during dry season were studied by establishing salt budget with evaporation and drainage estimates inside and outside a saline patch drainage was estimated by hydrus 1d modelling constrained by an hydrodynamic characterization and the profile of water contents at the end of dry season evaporation rates at the end of the dry season were computed by interpreting natural detailed profiles of deuterium d and chloride cl contents because of the drastic diminution of hydraulic conductivity at saturation with depth and the decrease of groundwater level at the end of the cropping season simulated hydrological balance with hydrus 1d pointed out zero cumulated fluxes for depths of 39 5 cm outside the saline patch and 37 5 cm inside the saline patch therefore all the chloride accumulated in the very upper layers during dry season comes from the chloride that was present in the 0 39 5 cm layers before the beginning of the drying inside the saline patch the tentative cl budget is coherent with the hypothesis of saturation of the profile by aquifer saline water during the flooding evaporation rates computed from the diffusion of chloride and deuterium at the end of the drying season when the aquifer level was 1 4 m deep range between 0 121 and 0 378 mm d 1 this does not sustain the assumption of a considerable salinity contribution from the aquifer during the dry season moreover evaporation estimates based on cl and d diffusion equilibrium showed depleted rates 38 63 inside the saline patch due to salt accumulation in the first 12 cm of the soil in the vapour transfer layer estimated evaporation rate based on the vapour movement of d was in the same order of magnitude than computed rate assuming liquid cl diffusion this coincidence is attributed to the liquid fluxes that occurred during the expansion of the vapour transfer layer during the progression of the evaporation front

a comprehensive numerical model for the thermodynamic and transport properties of h2o nacl fluids abstract saline fluids are common to a variety of geologic settings in earth s crust and upper mantle the binary system h2o nacl is commonly used to interpret data obtained from fluid inclusions and for geochemical modeling of mass and energy transport and fluid rock interaction modeling of fluid properties in this binary system has generally relied on piecemeal compilations from available models specific to certain properties whereas a standalone comprehensive tool has been lacking here we present a new computer package entitled probrine properties of brine to evaluate the thermodynamic and transport properties of h2o nacl fluids over the range of temperatures from 0 to 1000 c pressure from 1 to 5000 bar and salinity from 0 to 100 wt nacl probrine is designed to calculate a wide range of thermodynamic and transport properties including but not limited to phase equilibria liquid vapor and halite molar volume density specific enthalpy and viscosity the program is also equipped to calculate derived properties such as 1 the coefficient of isobaric thermal expansion 2 the coefficient of isothermal compressibility 3 the reduced susceptibility 4 the isobaric specific heat capacity and the fluxibility in addition the model will calculate solubility of the following six minerals fluorapatite calcite corundum fluorite rutile and quartz as well as the respective temperature and pressure derivatives which can be used to predict mineral dissolution and precipitation along a flow path moreover the program is equipped to interpret fluid inclusion data the program is written in visual basic vba in microsoft excel and is released open source allowing a user full scope to review copy modify and expand the program code

the magma ocean concept and lunar evolution the model of lunar evolution in which the anorthositic plagioclase rich oldest crust of the moon is formed over a period of 300 myr or less by crystallization as it floats on a global ocean of magma tens or hundreds of km thick is examined in a review of petrological and theoretical studies consideration is given to the classification of lunar rocks the evidence for primordial deep global differentiation constraints on the depth of the molten zone the effects of pressure on mineral stability relationships mainly liquid vs mainly magmifer ocean models and the evidence for multiple ancient differentiation episodes a synthesis of the model of primordial differentiation and its aftereffects is presented and the generalization of the model to the earth and to mars mercury venus and the asteroids is discussed

cogenetic rock fragments from a lunar soil evidence of a ferroan noritic anorthosite pluton on the moon abstract the impact that produced north ray crater apollo 16 landing site exhumed rocks that include relatively mafic members of the lunar ferroan anorthositic suite bulk and mineral compositions indicate that a majority of 2 4 mm lithic fragments from sample 67513 including impact breccias and monomict igneous rocks are related to a common noritic anorthosite precursor compositions and geochemical trends of these lithic fragments and of related samples collected along the rim of north ray crater suggest that these rocks derived from a single igneous body this body developed as an orthocumulate from a mixture of cumulus plagioclase and mafic intercumulus melt after the plagioclase had separated from any cogenetic mafic minerals and had become concentrated into a crystal mush 70 wt plagioclase 30 wt intercumulus melt we present a model for the crystallization of the igneous system wherein system is defined as cumulus plagioclase and intercumulus melt the initial accumulation of plagioclase is analogous to the formation of thick anorthosites of the terrestrial stillwater complex however a second stage of formation is indicated involving migration of the cumulus plagioclase intercumulus melt system to a higher crustal level analogous to the emplacement of terrestrial massif anorthosites compositional variations of the lithic fragments from sample 67513 are consistent with dominantly equilibrium crystallization of intercumulus melt the highly calcic nature of orthocumulus pyroxene and plagioclase suggests some reaction between the intercumulus melt and cumulus plagioclase perhaps facilitated by some recrystallization of cumulus plagioclase bulk compositions and mineral assemblages of individual rock fragments also require that most of the mafic minerals formed in close contact with cumulus plagioclase not as separate layers the distribution of compositions and by inference modes has a narrow peak at anorthosite and a broader larger peak at noritic anorthosite characteristics of the samples and their geochemical trends imply an origin in a system that was large relative to the unknown size of the impact that produced the brecccas of ferroan noritic anorthosite composition that were excavated later by the formation of north ray crater and they appear to be consistent with an origin of the suite within a perched plagioclase cumulate if the moon s crust formed by accumulation of plagioclase in a magma ocean ferroan noritic anorthosite formed as an orthocumulate is an alternative to extensive adcumulus formation of ferroan anorthosite 90 vol plagioclase this provides a relatively mafic ferroan anorthositic component 15 vol mafics which is required by mass balance models of compositions of polymict lunar crustal materials the inferred bulk composition of the system of cumulus plagioclase and intercumulus melt is similar to that of ferroan regolith breccia macalpine hills 88104 5 a lunar highland meteorite and may represent a common and widespread component of the moon s early highland crust

lunar granulites and their precursor anorthositic norites of the early lunar crust lunar granulites are breccias with metamorphic textures they are not pristine having been contaminated with meteoritic siderophiles nonetheless they constitute an abundant class of highlands rocks that are important because they are ancient and kreep free they may represent our best samples of the early lunar crust the granulites can be divided into ferroan and magnesian groups and each group can be subdivided on the basis of mineral composition and ree concentrations textural and compositional data show that some of the granulites especially 67215 and 67415 may be derived from distinct anorthositic norite precursors while some other granulites 79215 78155 are clearly polymict even the polymict granulites probably had anorthositic norites as their dominant precursors and not anorthosites norites or troctolites the granulites have compositions similar to those of the two lunar meteorites one of which yamato 791197 is ferroan the other alha81005 magnesian these meteorites are soil breccias from an unknown location distant from the apollo landing sites and contain anorthositic norites as abundant clasts compositions of granulites and lunar meteorites more closely resemble the average composition of lunar highlands as determined by remote sensing than do those of any other returned lunar samples the predominance of plutonic anorthositic norite precursors in material having the composition typical of highlands suggests that plutonic anorthositic norites were more abundant in the early lunar crust than is implied by their scarcity among pristine rocks from apollo missions

understanding groundwater systems and their functioning through the study of stable water isotopes in a hard rock aquifer maheshwaram watershed india summary groundwater degradation through abstraction contamination etc shows a world wide increase and has been of growing concern for the past decades in this light the stable isotopes of the water molecule 18 o and 2 h from a hard rock aquifer in the maheshwaram watershed andhra pradesh india were studied this small watershed 53 km 2 underlain by granite is endorheic and representative of agricultural land use in india with more than 700 bore wells in use in such a watershed the effect of overpumping can be severe and the environmental effects of water abstraction and contamination are of vital importance a detailed and dynamic understanding of groundwater sources and flow paths in this watershed thus is a major issue for both researchers and water managers especially with regards to water quality as well as the delimitation of resources and long term sustainability to this end the input from monsoon precipitation was monitored over two cycles as well as measuring spatial and temporal variations in 18 o and 2 h in the groundwater and in precipitation individual recharge from the two monsoon periods was identified leading to identification of periods during which evaporation affects groundwater quality through a higher concentration of salts and stable isotopes in the return flow such evaporation is further affected by land use rice paddies having the strongest evapotranspiration

high resolution profiling of the stable isotopes of water in unsaturated coal waste rock summary characterization of the rate of water migration through unsaturated mine waste rock dumps is an essential element in assessing the chemical loading from these landforms yet our understanding of how water moves into through and out of waste rock is incomplete to further understand the rates and magnitude of percolation through waste rock deep high resolution every 0 1 4 5 m depth profiles of the stable isotopes of water 2h and 18o at two coal waste rock dumps and a natural alluvial deposit down gradient of one of the dumps were collected in the elk valley british columbia canada the profiles were generated using vapor equilibrium techniques applied to continuous core samples collected using dry sonic drilling methods elevated core temperatures up to 80 c were measured during sonic coring the isotopic values of pore waters measured in the core samples were corrected for water loss to the atmosphere attributed to the elevated core temperatures the average isotopic composition of the core samples were compared to water collected from rock drains discharging from the base of the dumps the results indicate that high resolution profiles of 2h and 18o can be measured to depths of 86 m in coal waste rock dumps and based on the seasonal cycles in the isotopic composition of recharging water can be used to characterize the migration of recharge water within these dumps these profiles also suggest that recharge into these dumps occurs from both rain as well as snow melt and may be as high as 400 600 mm yr 60 75 of annual precipitation combined with the relatively low volumetric water contents of these dumps 5 10 the rates of water migration through the dumps are tens of meters each year

distribution of oxygen and hydrogen isotopes in shallow groundwaters from southern india influence of a dual monsoon system oxygen and hydrogen isotopic investigation of groundwater and river water samples from the southern indian peninsula was undertaken to characterise the isotopic nature of the near surface water sources and provide basic framework for future hydrological studies it is assumed that the shallow groundwater retains the isotopic signature of the local precipitation averaged over a few tens of years except in a few cases where the same gets modified by post precipitation evaporation and or recharge contribution from surface water bodies therefore isotopic character of the groundwater can in principle be used to determine the relative influence of the different vapour sources contributing to the local regional precipitation and to characterise the modifications before groundwater recharge in the present context vapour sources for two rainy seasons namely southwest sw and northeast ne monsoon are respectively the indian ocean arabian sea and the asian continental sources together with the bay of bengal this study shows that i the regions dominated by ne monsoon have distinctly depleted isotopic composition compared to those dominated by sw monsoon ii the 18o d regression line slope of 6 in the east coast region is lower than that expected for local precipitation suggesting secondary evaporation iii the orography of the western ghats hill ranges plays a significant role in controlling the isotopic distribution along the west coast region iv the low d excess values in most part of study area indicate secondary evaporation v the high d excess values over the deccan plateau region in the nw part of the study area suggest admixture of recycled moisture with the inflowing oceanic vapour

petrologic province maps of the lunar highlands derived from orbital geochemical data orbital and sample geochemical data from the lunar highlands are combined in variation diagrams to determine a the coincidence between the two data sets and b the geologic validity of extrapolating observed diagrammatic relations to an image format we examined three variation diagrams mg 100 mg mg fe molar versus th ti c ratio normalized to chondrites al versus mg th ti c and fe versus th ti c for the orbital data within each diagram we establish a petrologic classification based on the data s clustering or coincidence with sample compositions or both the spatial distributions of each diagram s classes are shown as petrologic units on color coded classification maps the mg th ti c diagram which is similar to the mg sm ti c diagram that has been used in sample studies is inferior to the al mg th ti c diagram in discriminating kreep from mg suite rock types the orbital geochemical spectrometers analyzed the regolith in which mg varies much less than al although the fe th ti c diagram shows a diverse distribution of orbital data similar to that shown by the al mg th ti c diagram it is unable to discriminate adequately between kreep and mg suite rock types the fe th ti c diagram is nonetheless very useful because of its greater areal coverage orbital and soil sample compositions of the four highland landing sites correspond in both the al mg th ti c and the fe th ti c data the diagrams show some units of virtually pure anorthosite and norite most units show the effects of mixing of pristine rock types in the regolith one unit which dominates the eastern limb and farside highlands has a composition so mafic that with the chosen end members it requires a 30 mare basalt component we interpret this to mean that the highlands experienced a significantly greater amount of mare volcanism before the end of heavy bombardment than has been previously suggested the average global composition of the highlands under the apollo groundtracks is that of anorthositic gabbro an average that has significant implications for the role of near global plagioclase fractionation in lunar crustal genesis our analysis has shown that the simultaneous use of orbital and sample geochemical data in variation diagrams can 1 bridge the mechanical gap between orbital and sample studies by relating orbital data to sample petrology 2 present the results of several elemental databases as one map for rapid geologic analysis and 3 display quantitative mixing relations of different crustal materials in a spatial format this technique will be valuable for petrologic interpretation of the global geochemical data to be received from the future lunar geosciences orbiter mission

the evolution of a porphyry cu au deposit based on la icp ms analysis of fluid inclusions bajo de la alumbrera argentina the chemical and physical evolution of magmatic to hydrothermal processes in the porphyry cu au deposit of bajo de la alumbrera northwestern argentina has been reconstructed with a quantitative fluid inclusion study fluid inclusion petrography microthermometry and single inclusion microanalysis by excimer laser ablation inductively coupled plasma mass spectrometry la icp ms are combined to determine the evolution of pressure temperature and ore metal concentrations including cu and au in the fluids complementary hydrogen and oxygen isotope analyses are used to further constrain the water sources in the evolving system the combined data provide a new level of insight into the mechanisms of metal sourcing and ore mineral precipitation in a porphyry style magmatic hydrothermal system based on previously reported observations of the igneous geology alteration geochemistry and veining history of the subvolcanic porphyries at alumbrera the distribution of fluid inclusion types in space and time is documented six major inclusion types are distinguished the highest temperature brine inclusions up to 750 c p 1 kbar are mainly recorded in barren quartz magnetite veins in the core of the alteration system these polyphase brine inclusions halite sylvite multiple opaque and transparent daughter crystals are interpreted as the most primitive magmatic fluid recorded at the level of the deposit they are of moderately high salinity 50 60 wt nacl equiv dominated by nacl kcl and fecl 2 and contain on average 0 33 wt percent cu and 0 55 ppm au upon cooling and decompression these saline liquids exsolve a vapor phase which is preferentially enriched in cu relative to its main salt components but probably plays a minor role in the formation of this particular deposit because of the inferred small mass fraction of vapor cooling and decompression from the highest initial p t conditions down to about 450 c causes magnetite k silicate alteration but no saturation in au or cu sulfides as recorded by continually high ore metal concentrations in the fluid inclusions coprecipitation of cu and au as chalcopyrite and native gold some early bornite occurs over a narrow range of decreasing fluid temperature with cooling from 400 to 305 c the cu concentration in the brine drops by about one order of magnitude to less than 0 07 wt percent without a proportional decrease in major salt components ore mineral precipitation extracts 85 percent of the cu and au from the fluid it is associated with potassic alteration as shown by a concomitant decrease in the k na ratio of the cooling magmatic brine and by an increase in its ba and sr concentrations elements which are probably liberated in the destruction of calcic igneous minerals the fluid chemical data demonstrate that the metal ratios in this and probably many other porphyry style ore deposits are primarily controlled by the magmatic source of the ore brines on the other hand the final hypogene ore grade of the deposit is controlled by the efficiency of ore mineral precipitation at alumbrera metal extraction is governed by the efficiency of cooling a high flux of magmatic fluid within a small rock volume dilution of residual magmatic fluids as recorded by aqueous fluid inclusions of decreasing salinities and temperatures below 295 c follows after the main stage of copper introduction and is associated with feldspar destructive phyllic alteration geometric relationships fluid analyses and stable isotope data together indicate that phyllic alteration results from postmineralization hydrothermal activity involving minor mixing between meteoric water residual brine and a waning input of magmatic vapor

magmatic evolution of lunar highland rocks estimated from trace elements in plagioclase a new bulk silicate moon model with sub chondritic ti ba sr ba and sr al ratios abstract the compositions of host magmas of ferroan anorthosites fan host magmas were estimated from secondary ion mass spectrometry analyses of plagioclase in lunar highland rocks the evolution of the magmas was investigated by considering phase relations based on the melts algorithm and by re examining partition coefficients for trace elements between plagioclase and melts data little affected by post magmatic processes were selected by using plagioclase with relatively primitive sc and co contents the fan host magma contained 90 174 ppm sr 40 119 ppm ba and 0 5 1 3 tio2 and had sub chondritic sr ba and ti ba ratios it is difficult to account for the formation of fan host magma on the basis of magma evolution processes of previously proposed bulk silicate moon models with chondritic ratios for refractory elements at global scale therefore the source of the fan host magma must have had primordial sub chondritic sr ba and ti ba ratios the fan host magmas were consistent in refractory elements with the estimated host mafic magma for feldspathic crust based on lunar meteorites and some very low ti mare rocks from lunar meteorites here we propose an alternative bulk silicate moon model the cbsm model which is enriched in crustal components of proto bodies relative to the present whole earth moon system

composition and evolution of the lunar crust in the descartes highlands apollo 16 samples from the north ray crater ejecta blanket apollo 16 were investigated by petrographic microscope electron microprobe instrumental neutron activation and xray fluorescence analyses and 40ar 39ar and rb sr dating techniques nine major groups of monomict and polymict breccias were defined on the basis of microscopic texture and these were further subdivided into chemical subgroups on the basis of characteristic elements such as al mg fe cr ree ni and co the polymict breccias fragmental breccias granulitic breccias and impact melt breccias are the result of multiple impact induced mechanical mixing and melting and of thermal and impact metamorphism of rock and mineral clasts derived from primordial igneous crustal rocks for calculations of mixing models it was found that end members consisting of the pristine igneous rock components present as discrete samples at the apollo 16 site and supplemented by kreep dunite and a meteoritic component yield the best fits for the composition of polymict breccias the end member rocks a re ferroan anorthosite various magnesian gabbronorites including sodic ferrogabbro and feldspathic lherzolite and spinei troctolite the following model is proposed for the composition and stratigraphy of the target for north ray crater the lower section of the stratigraphy is composed of a megabreccia with clasts of highly feldspathic polymict breccias kreep free old eastern highland rock suite interpreted as nectaris ejecta descartes formation the top section contains kreep bearing polymict breccias kreep bearing young western highland rock suite and appears to be similar to the lithologies found in the cayley plains this material interpreted as cayley formation may be a distant facies of imbrium basin ejecta deposits of the imbrium basin the petrographic differences between these two major selenographic units the descartes and the cayley formations in the apollo 16 area are more distinct than the chemical differences the petrographic and chemical composition of the primordial igneous upper crust in the regions of the nectaris and imbrium basins has been calculated by subtraction of the kreep and meteoritic components from the bulk composition of the descartes and cayley materials the nectaris crust which is better constrained consists of 86 87 a northosite 4 sodic ferrogabbro 0 5 1 3 feldspathic lherzolite 6 8 regular magnesian gabbronorite 1 8 2 8 dunite and 0 1 spinel troctolite a model for the evolution of the upper lunar crust in the descartes highlands is proposed on the basis of isotope ages and clast matrix relationships of polymict breccias essential features of this model in sequenial order are 1 development of multiple layers of kreep free early feldspathic fragmental megabreccias and impact melt sheets on the primordial crust in the time period from 4 4 aeons to the time of the nectaris impact which could have occurred as late as 3 85 aeons ago 2 excavation of these megabreccias by the nectaris event and deposition of a nectarian feldspathic fragmental megabreccia in the descartes area 3 introduction of kreep basaltic material into the upper crust mainly west and northwest of the descartes site and formation of kreepy impact melt sheets most probably from 4 05 to 3 80 aeons ago 4 imbrium impact at 3 8 aeons ago and deposition of kreep bearing imbrian feldspathic fragmental breccias at the descartes site which form the cayley formation and 5 redeposition mixing and melting of all preexisting breccias yielding kreep bearing and kreep poor post cayley fragmental breccias and melt ejecta glass bombs as the result of small impacts craters 1 5 km in diameter in the cayley plains and the descartes mountains respectively

evolved mare basalt magmatism high mg fe feldspathic crust chondritic impactors and the petrogenesis of antarctic lunar breccia meteorites meteorite hills 01210 and pecora escarpment 02007 antarctic lunar meteorites meteorite hills 01210 and pecora escarpment 02007 are breccias that come from different regolith lithologies on the moon met 01210 is composed predominantly of fractionated low ti basaltic material and is classified as an immature predominantly basaltic glassy matrix regolith breccia pca 02007 is a predominantly feldspathic regolith breccia consisting of metamorphosed feldspathic noritic troctolitic and noritic anorthosite clasts agglutinate and impact glasses as well as a number of basaltic clasts with mare and possible non mare affinities the basalt clasts in met 01210 have undergone fenner trend enrichments in iron and may also have witnessed late stage crystallization of zircon or a zirconium rich mineral some of the features of met 01210 are similar to other basaltic lunar breccia meteorites e g northwest africa 773 elephant moraine 87521 96008 yamato 793274 981031 but it is not paired with them the presence of metamorphic anorthositic clasts as well as agglutinates indicates a small regolith component similarities with previously discovered evolved e g lapaz icefield 02205 northwest africa 032 and ferroan e g asuka 881757 yamato 793169 basaltic lunar meteorites suggest a similar mare source region for met 01210 despite lack of evidence for pairing pca 02007 shares many features with other feldspathic regolith breccias e g yamato 791197 queen alexandra range 94281 including a high mg fe whole rock composition glass spherules agglutinate fragments and a diverse clast inventory spanning the range of ferroan anorthosite and high magnesium suite rocks some of the basalt fragments in this sample are fractionated and have an igneous origin however the majority of the basalt fragments are impact melt clasts pca 02007 supports previous studies of feldspathic lunar meteorites that have suggested an aluminous crust for the moon with compositions more similar to magnesium granulite breccias than ferroan anorthosites a chondrule like fragment found in pca 02007 and unlike any previously described lunar material is described and tentatively identified as the remnants of a chondritic lunar impactor this clast is porphyritic with equant olivines that have forsterite rich cores fo 98 extreme normal zonation to more fayalitic rims fo 44 and a mineral assemblage with rare earth element abundances distinct from described lunar material and more similar to chondrules found in ordinary or carbonaceous chondrites its discovery and description is significant for understanding the composition of lunar impactors previously the main evidence for chondritic lunar impactors was from chondritic relative abundances and near chondritic ratios of highly siderophile elements in lunar impact melt breccias however the presence of this clast along with two other chondritic clasts from apollo soils 12037 and 15602 provides clues to the identity of ancient meteorite impactors on the moon

experimental studies in model fluid systems numerous observations provide strong evidence that fluid fluid coexistence is a widespread phenomenon in many geological processes i oceanic hydrothermal fluids display a wide range in salinity which clearly indicates fluid phase separation of the circulating seawater see foustoukos and seyfried 2007a ii selective enrichment of certain elements and coeval entrapped inclusions of different co existing fluids highlight the role immiscible fluids play in ore formation see heinrich 2007a iii trace element and stable isotope characteristic as well as equilibrium mineral assemblages in contact aureoles prove immiscible fluids to be a ubiquitous feature in most contact metamorphism see heinrich 2007b iv small scale fluid heterogeneity in eclogitic rocks indicate fluid immiscibility to occur in metamorphic rocks up to high or even ultra high pressure see heinrich 2007b unfortunately fluids are principally non quenchable phases and direct quantitative information on fluid properties at p and t is in most cases not available experimental studies are thus central in studying geologic fluids in general and co existing fluids in particular they are still the primary source of quantitative information on physicochemical properties of co existing crustal fluids they allow e g determine i fluid phase relations as function of p t and x ii physical fluid properties like density and viscosity and iii trace element and isotope fractionation between co existing fluids but also between co existing fluids and solids the experimental data can then be used as input in forward modeling approaches the results and or predictions of which may then be tested in natural systems see driesner and geiger 2007 experimental data on co existing fluids in systems of geological relevance already date back to the flrst half of last century e g keevil 1942 since the 1960ies numerous systematic experimental studies on fluid fluid phase relations at crustal p and t conditions were performed e g sourirajan and kennedy

groundwater recharge estimation using chloride deuterium and oxygen 18 profiles in the deep coastal sands of western australia the depth distributions of environmental chloride deuterium and oxygen 18 in the deep sands 20 m were monitored with a view to estimate average recharge to groundwater the investigated area is located on the southwestern coast of western australia and supports a perennial native woodland vegetation by using a steady state model based on the conservation of chloride the average areal recharge was estimated to be approximately 15 of the average precipitation 775 mm yr 1 whilst the cl concentration of groundwater was relatively uniform there was a considerable spatial variability in the depth distribution of cl in the unsaturated zone an approximate method of data analysis is developed application of this to cl data shows that possibly some 50 of the total annual recharge occurs via movement of water through preferred pathways thus bypassing the soil matrix stable isotope deuterium and oxygen 18 data show that there has been some isotopic enrichment due to evaporation of the rainfall but the extent of enrichment appears to be too small to estimate recharge rates reliably it is argued that relatively small isotopic enrichment occurs in the system studied since the direct evaporation from soil is a rather small component of the total evapotranspiration the observations on the depth distribution of isotopes qualitatively support the presence of a bimodal system for water movement through the profile as was suggested by the analysis of chloride data

hydrothermal evolution of the el teniente deposit chile porphyry cu mo ore deposition from low salinity magmatic fluids the magmatic hydrothermal evolution of the el teniente porphyry cu mo deposit in the central andes in chile is reconstructed based on field relationships scanning electron microscopy cathodoluminescence petrography and fluid inclusion analysis by microthermometry and laser ablation inductively coupled plasma mass spectrometry la icpms three major stages of cu mo mineralization are observed following the barren hydrothermal stage 1 the stage 2 mineralization is characterized by quartz anhydrite stockwork veins and breccias with chalcopyrite bornite and molybdenite both stages 1 and 2 are associated with pervasive potassic alteration quartz anhydrite veins with chalcopyrite bornite and molybdenite associated with phyllic alteration represent stage 3 mineralization stage 4 mineralization linked to the formation of the large braden diatreme is characterized by breccias and rare veins containing a lower temperature assemblage with tourmaline sericite and lesser tennantite bornite and chalcopyrite with late gypsum in local vugs ten fluid types are distinguished in this study based on petrographic and microthermometric criteria such as phase proportions daughter minerals homogenization behavior and salinity the hydrothermal evolution across the stages of cu deposition is characterized by the contraction of a vapor phase originating by phase separation during stage 2 overall cooling of the system at pressures fluctuating around the two phase fluid surface led to a transition from a two phase fluid state dominated by vapor at 410 c and 300 bars in stage 2 to a single phase low salinity fluid derived from cooling and contraction of magmatic vapor to a liquid which dominates during stage 3 mineralization at 350 c and 200 bars copper mineralization mainly formed from the vapor phase and its low salinity liquid derivatives representing a large volume of fluid with an initially high cu content 1 2 0 4 wt cu copper sulfides precipitated upon cooling between 410 and 320 c indicated by a drop of cu na k mn fe ratios of over four orders of magnitude through the evolution of the deposit from stage 2 to stage 4 the highest mo concentrations occur in residual brines resulting from extreme boiling as indicated by concurrent halite saturation recent geochronology cannell 2005 maksaev et al 2004 suggests a relatively long lived magmatic hydrothermal system at el teniente our fluid chemical data show no evidence for major crystal fractionation in a large fluid generating upper crustal magma chamber because cs na k mn fe is constant from pre ore to all syn ore fluids however the initiation of copper mineralization was associated with a 4 to 10 fold increase in the concentration of cu mo li and fe in the inferred main ore forming input fluid compared with pre ore fluids of intermediate salinity and otherwise very similar major and trace element ratios these data indicate that injection from depth of an exceptionally cu mo li and probably also s rich volatile phase into an already actively evolving upper crustal magmatic hydrothermal system triggered the formation of this unusually large and rich copper deposit

an ancient sm nd age for a ferroan noritic anorthosite clast from lunar breccia 67016 strontium and neodymium systematics have been examined in a clast of ferroan noritic anorthosite from apollo 16 breccia 67016 two splits 328 and 326 of the same clast give different sm nd results split 328 gives a well defined internal isochron age of 4 562 0 068 ga and an initial 143nd 144nd ratio of 0 50673 10 corresponding to nd 0 1 0 2 2 optimized error relative to the murchinson carbonaceous chondrite the pyroxene separate from split 326 lies on the same isochron in contrast the plagioclase and whole rock from split 326 fall below this line indicating a small scale disturbance of the sm nd system this may reflect either an isotopic exchange between the plagioclase and a low sm nd mineral or a loss of radiogenic 143nd from the plagioclase possibly during the period of major impacts at 3 9 ga the preservation of an extremely old age for the noritic ferroan anorthosite 67016 328 suggests a rapid cooling of this rock at an early stage in the evolution of the lunar magma ocean this old age is also consistent with giant impact models for the formation of the moon but implies a relatively early event pre 4 50 ga and therefore rapid accretion and differentiation of the terrestrial planets

anatexis of lunar cumulate mantle in time and space clues from trace element strontium and neodymium isotopic chemistry of parental apollo 12 basalts abstract in an effort to elucidate the processes of lunar mantle melting and the magma evolution of mare basalts within oceanus procellarum on the western lunar near side we have analyzed seven fine grained to vitrophyric apollo 12 basalts for trace elements five of these also have been analyzed for nd and sr isotopic compositions these samples represent all three main groups identified among the apollo 12 mare basalts and have been proposed as parental melts to their respective groups i e olivine pigeonite and ilmenite basalts the sources for these low ti mare basalts are postulated to have formed from crystallization of a global magma ocean li be systematics combined with ree data indicate that the specific sources for the apollo 12 low ti mare basalts were generated after 82 94 crystallization of this lunar magma ocean in fact it seems that all mare basalts analyzed from the apollo collections were generated from cumulates precipitated in the last 20 of the magma ocean chemical compositions of fine grained pigeonite and olivine basalts are consistent with 7 9 nonmodal in proportions not defined by experimental petrology and phase equilibria melting of a source consisting of 48 olivine 30 calcic clinopyroxene and 22 pigeonite as per neal et al 1994b sm nd and rb sr abundance data also suggest that the pigeonite and olivine basalt source contained from 0 3 to 0 5 trapped residual liquid from the magma ocean the compositions of the two fine grained ilmenite basalts are consistent with 5 7 partial melting of a source with subequal proportions of olivine 45 5 and pigeonite 42 5 and lesser amounts of clinopyroxene 11 5 and entrained plagioclase 0 5 furthermore the ilmenite source was nearly devoid of trapped liquid isotopic systematics of the apollo 12 fine grained parental basalts are consistent with their derivation from two distinct mantle source regions both of these sources were lree depleted for extended periods of time up to 600 million years for the ilmenite basalt source and up to 900 million years for the pigeonite and olivine basalt source due in part to the relatively small proportion of low sm nd trapped residual magma ocean liquid in the source by integrating this information on parental low ti apollo 12 basalts with mare basalt and picritic glass data from other landing sites as well as telescopic and remote sensing data we propose a model for melting of the lunar interior the upper 400 500 km of the lunar mantle is a consequence of incipient melting of the moon and formation of a global magma ocean this magma ocean became progressively enriched in incompatible elements as it precipitated the cumulate upper mantle this incompatible earliest extensive mare magmas high ti mare basalts were generated at shallow depths in the mantle from cumulate source regions that had trapped relatively large proportions of this incompatible element enriched residual magma ocean liquid these source regions also contained the late crystallizing phase ilmenite and thus generated high ti magmas the trapped liquid component contained elevated abundances of heat producing elements k u and th increasing the fertility of associated source regions with time melting moved progressively deeper in the mantle to source regions with less of the residual heat producing magma ocean liquid due to density contrasts the ilmenite bearing upper portions of the lunar mantle sank into the cumulate pile possibly carrying more fertile material with it and allowing melting of more mg enriched source regions to form the high ti picritic glass beads thus the major controlling factors in the melting of the lunar interior could be the proportion of trapped magma ocean liquid in the cumulate source and the sinking of more fertile ilmenite bearing material into the lower mantle

pedogenic carbonate stable isotope record of environmental change during the neogene in the southern great plains southwest kansas usa oxygen isotopes and paleoclimate during the evolution of c4 dominated grasslands neogene strata in the meade basin southwest kansas preserve numerous superposed calcareous paleosols in sections that range in age from the clarendonian north american land mammal age nalma 12 0 9 0 ma early late miocene to the early irvingtonian nalma ca 2 5 ca 1 ma early pleistocene the carbon isotope compositions 13 c relative to vienna peedee belemnite vpdb of pedogenic carbonates from these sections record the protracted regional increase in the abundance of grasses using the c 4 photosynthetic pathway over this interval with the first appearance of a modern like grassland ecosystem having 70 c 4 biomass around 1 3 ma we use the stable oxygen isotope composition 18 o relative to vienna standard mean ocean water vsmow of 194 paleosol carbonates from 19 measured sections to reconstruct the climatic conditions in the meade basin during the rise of c 4 grasses to ecological dominance in the region pedogenic carbonate 18 o values are sensitive to soil temperature and the 18 o of soil water and hence they are a paleoclimate proxy carbonate 13 c values do not exhibit consistent trends in relation to 18 o values indicating no consistent relationship between short term climatic conditions in terms of temperature or aridity and the abundance of c 4 biomass mean carbonate 18 o values within biostratigraphic intervals decrease from the clarendonian 25 3 0 72 to the early and middle blancan 21 8 0 87 and 22 1 0 69 respectively and they also exhibit a decreasing trend in the late blancan early irvingtonian from 25 to 21 the increase in 18 o values between the end of the middle blancan and the beginning of the late blancan early irvingtonian sections could reflect the onset of northern hemisphere glaciation and a change in the isotope composition of the hydrosphere due to increased ice volume the long term trend in 18 o values suggests that c 4 biomass increased coincident with some combination of decreasing temperature increasing proportion of winter precipitation recharge of soil water and or increasing soil moisture thus the ecological dominance of c 4 grasses in the region today does not seem to be linked to warmer temperatures or increased aridity

trace element compositions and br cl ratios of fluid inclusions in the tsushima granite japan significance for formation of granite derived fluids abstract fluid inclusions in quartz samples from a miarolitic cavity two quartz veins and a hydrothermal ore vein in the tsushima granite japan were analyzed by particle induced x ray emission to examine the chemistry and process of formation of hydrothermal fluids in an island arc granite most of the inclusions were polyphase or vapor and there were smaller numbers of two phase aqueous inclusions the inclusions contained cl k ca ti mn fe cu zn ge br rb sr ba and pb for each inclusion there was a strong positive correlation between cl content and contents of other elements identified concentration ranges for most elements other than rb and ge in polyphase inclusions from the miarolitic cavity were comparable to those from cavities in alkaline granites those from the ore vein were comparable to large scale continental hydrothermal ore deposits the lower rb and higher ge contents in the polyphase inclusions of the tsushima granite may be characteristic of hydrothermal fluids from calc alkaline granites in an island arc setting br cl ratios by weight for the vapor and two phase inclusions were 0 0013 0 0030 and differed among the three geological settings br cl ratios of polyphase inclusions increased with increasing cl content in single crystal and polycrystalline quartz and high values of more than 0 0100 were found the high br cl ratios and the differences among the geological settings sampled may be due to pressure dependences of partitioning of cl and br between fluid and magma during fluid segregation and between liquid and vapor during boiling using a simple model based on these dependences we calculated br cl ratios greater than 0 01 in brine generated at pressures

additional complexity in the lunar crust petrology of sodic anorthosites and sulfur rich ferroan noritic anorthosites lunar breccia 67016 contains two suites of unusual highlands rocks sulfur rich noritic anorthosites and sodic anorthosites mineral compositions of the sulfur rich noritic anorthosites closely match those of ferroan anorthosites unusually large amounts of sulfides and sulfidation reactions involving olivine in these clasts probably reflect endogenous volatile transfer the sodic anorthosites are mafic poor with mineral compositions intermediate between those of pristine ferroan and alkali anorthosites rare examples of pristine rocks with similar mineral compositions are known and may represent a distinct class of lunar crustal rocks

geology and fluid characteristics of the mina velha and mandiocal orebodies and implications for the genesis of the orogenic chega tudo gold deposit gurupi belt brazil the chega tudo gold deposit is located in the gurupi belt of northern brazil gold mineralization in the mina velha upper level and mandiocal intermediate and lower levels orebodies is hosted in highly strained paleoproterozoic 2148 2160 ma felsic to intermediate metavolcanic rocks and schists that record greenschist facies metamorphism the orebodies are broadly concordant with the regional northwest oriented foliation and mineralization comprises thick quartz vein sets and small quartz carbonate sulfide veinlets and enclosing hydrothermally altered host rocks the hydrothermal mineral assemblage is postpeak metamorphism syn to late tectonic and includes quartz calcite chlorite white mica pyrite subordinate chalcopyrite and traces of sphalerite and galena free milling gold occurs in sulfide poor veins in the upper and lower zones of the deposit whereas refractory gold was deposited in fractures of pyrite and quartz in the more gold enriched intermediate lower level fluid inclusion and stable isotope o h c and s data indicate that the two styles of gold deposition were produced by a combination of fluid immiscibility fluid rock reactions sulfidation carbonatization and probably mixing occurring in two discrete stages within a single mineralizing event associated with fluid flow within and around an active shear zone under fluctuating pressure conditions the refractory gold was deposited at 340 to 370 c from a co2 ch4 h2o nacl fluid having salinity of 5 8 2 7 wt percent nacl equiv variable co2 contents typically 12 22 mol and up to 6 mol percent ch4 the 18o and d values of this fluid are 7 9 to 9 4 per mil and 29 to 37 per mil respectively indicating a metamorphic origin carbon isotopes show contrasting values in fluid inclusion co2 13c 24 1 and calcite 13c of 3 8 the strongly negative value of fluid inclusion co2 is interpreted to be an organic signature acquired at the site of deposition by reaction of the deeply sourced ore forming fluid with carbonaceous schists present in the deepest part of the deposit the higher value for calcite probably records a crustal source oxygen fugacities calculated for the whole range of t p xco2 conditions yielded log fo 2 between 28 7 and 30 5 indicating reduced conditions for the fluid which is in agreement with the mineral paragenesis fluid inclusion compositions and sulfur isotope values the second fluid responsible for the deposition of the free milling gold in veins and probably part of the gold of the lower zone of the deposit had a lower temperature 330 340 c this co2 h2o nacl fluid had a salinity of 1 6 to 2 5 wt percent nacl equiv and contained 11 to 13 mol percent co2 the 18o and d values of this fluid are 5 3 to 7 2 per mil and 12 to 30 per mil respectively also indicating a metamorphic source the 13c value of fluid inclusion co2 is 6 9 per mil likely representing a mantle derived carbon source log fo 2 values between 30 5 and 31 5 also indicate slightly more reduced conditions for this fluid both fluids had near neutral ph between 5 and 6 2 and 34s values of h2s between 0 2 and 1 0 per mil interpreted to reflect derivation of sulfur from magmatic sulfides

tracing infiltration and recharge using stable isotope in taihang mt north china the groundwater in headwater region is an important recharge source for the adjacent mountain front plain in order to reveal the relationship among precipitation soil water and groundwater from june to september in 2004 stable isotopes deuterium and oxygen 18 in precipitation and soil waters at the depths of 10 20 30 50 70 90 and 110 cm were analyzed at two sites covered by black locust robinia pseudoacia l site a and grass predominated by themeda triandra t japonica willd tanaka and bothriochloa ischaemum b ischaemum l keng site b in an experimental catchment at taihang mt north china respectively the 18o of precipitation in daily rain events shows large variations 13 3 to 4 3 with a mean of 8 1 the 18o and d of soil waters along profiles in two sites suggest that the influence of canopy cover was just up to 10 cm in top soil water the soil water moved over the zero flux plane at 70 cm in depth is expected to escape the evaporative effect at the end of september in both sites the results show that the stable isotope instead of tritium as tradition can be used to trace the soil water behaviors based on the movement of isotopic peak along the vertical profiles in this semi arid and semi humid mountainous region the infiltration depths of soil water in taihang mt are 12 and 10 mm day from june to september in 2004 in site a and site b respectively tracing by stable isotope recharge fluxes of soil water to local groundwater are of 3 8 and 3 2 mm day in site a and site b respectively the results provide desirable information for assessment of local groundwater resources

freshwater recharge into a shallow saline groundwater system cooper creek floodplain queensland australia freshwater lenses have been identified as having penetrated the shallow regional saline groundwater beneath the cooper creek floodplain near ballera south west queensland piezometers were installed to evaluate the major element chemistry along a floodplain transect from a major waterhole goonbabinna to a smaller waterhole chookoo associated with a sand dune complex the floodplain consists of 2 7m of impermeable mud underlain by unconsolidated fluvial sands with a saline watertable waterholes have in places scoured into the floodplain the transect reveals that groundwater recharge takes place through the base of the waterholes at times of flood scour but not through the floodplain mud total dissolved solids rise with distance from the waterhole and independently of the presence of sand dunes stable water isotopes 2h and 18o confirm that recharge is consistent with and dependant on monsoonal flooding events following floods the waterholes self seal and retain water for extended periods with sulfate 34s and 18o isotopes suggesting bacterial reduction processes within the hyporheic zone and limited interaction between the surface water and groundwater during no flow conditions the area occupied by the freshwater lenses tds 5000 mg l is locally asymmetrical with respect to the channel flow direction extending down gradient along distances of 300 m

geochemistry of lunar crustal rocks from breccia 67016 and the composition of the moon global differentiation of the moon has produced a plagioclase rich crust overlying an ultramafic mantle we have conducted a major and trace element study of anorthositic clasts from an apollo 16 breccia to investigate the geochemical features of these highlands lithologies and their role in lunar crustal evolution samples analyzed for this study have aluminous alkali poor compositions and varied feo and mgo contents al2o3 25 35 na2o 0 3 1 k2o 1 ferroan noritic and 1 magnesian troctolitic respectively these mafic enriched varieties have considerably higher lithophile element concentrations at levels similar to that of the bulk lunar crust the ferroan noritic clasts may represent a fundamental type of igneous rock in the lunar crust which has not been widely recognized liyb ratios of highlands and mare rocks demonstrate the complementary nature of the lunar crust and mantle which is best explained by a global differentiation event such as crystallization of a magma ocean the most primitive mantle derived lunar material for which data are available the apollo 15 green glass has liyb virtually identical to those of the mafic enriched anorthosites providing an estimate of the magma ocean composition the moon and the earth have liyb ratios that are similar to each other but the absolute abundances of both li and yb appear to be higher in the moon the liyb ratios of the earth and moon are distinct from those of ci and ordinary chondrites and the eucrite parent body but are similar to those of cv co and el chondrites precluding a unique match between the composition of the earth and moon

spatio temporal variations of δ2h and δ18o in precipitation and shallow groundwater in the hilly loess region of the loess plateau china groundwater is of utmost significance to socio economic development and ecological recovery for the loess plateau however studies regarding the mechanism governing groundwater recharge over this area appear to be inadequate this study is to examine the spatio temporal variations of 2h and 18o in precipitation and shallow groundwater on the basis of this the mechanisms governing shallow groundwater recharge were explored precipitation and groundwater were sampled monthly from may to october during the period 2004 2006 at 13 sites in the chabagou catchment 187 km2 in the caopingxigou experimental watershed 0 1 km2 meteorological variables were observed and rainfall larger than 5 mm was sampled immediately after each rain event across the area 90 of the precipitation occurred from may to september primarily in the form of heavy rains or rainstorms with great spatial variability there were about 30 localized rains in each year it was indicated that there existed notable seasonality and pronounced spatial variability in precipitation isotopic compositions contributing factors and indications of isotopic compositions as well as their climatic indications such as monsoon intensities and mixing processes of water vapor were investigated the 2h 18o relation of groundwater was found to be 2h 3 22 18o 38 1 deviating from the local meteoric water line 2h 7 57 18o 3 9 the range of values in groundwater is shrunken to be 15 21 of that in individual precipitations and groundwater in the middle reaches shows a wider range of values isotopic results showed that groundwater originates from precipitation with hydrogen and oxygen isotopic compositions being 69 and 9 7 respectively and most groundwater experiences serious evaporation and adequate mixing with old water during infiltration or percolation in the aerated zone it was also founded that obvious fluctuations of isotopic compositions in groundwater mainly appear in the middle reaches especially at sites that are close to valleys suggesting varying sources of groundwater from precipitation precipitation runoff isotopically enriched surface water and or lateral recharge of adjacent groundwater

causes for large scale metal zonation around mineralized plutons fluid inclusion la icp ms evidence from the mole granite australia detailed reconstruction of the fluid evolution in several ore deposits associated with the sn w and base metal mineralized mole granite shows that multiple factors contributed to the zonal metal distribution around this intrusion information about the mechanism of ore formation was obtained from field relationships detailed petrographic studies and laser ablation inductively coupled plasma mass spectrometry la icp ms microanalysis of single fluid inclusions premineralization fluid inclusions in sn deposits are characterized by high sn w ratios whereas early fluid inclusions from w deposits contain higher w concentrations and comparatively low sn w ratios this indicates that the metal ratio in these deposits already was predefined by the composition of the magmatic input fluid however in both types of deposits the input fluid actually contained much higher concentrations of base metals pb zn cu etc than sn and w demonstrating that metal precipitation was highly selective the metal zonation around the mole granite therefore reflects both a compositional variation of the source fluid as well as sequential metal precipitation from it an additional process contributing to metal fractionation occurred by phase separation of the hydrothermal fluid into saline brine and low density vapor whereby cu b li as s ag la preferentially partitioned into the vapor phase analyses on six assemblages of unambiguously coexisting vapor and brine inclusions allowed direct determination of vapor brine distribution coefficients for 24 elements

origin of the shallow groundwater system in the southern voltaian sedimentary basin of ghana an isotopic approach the development and management of groundwater resources require an ability to understand and identify the recharge source to the groundwater system stable and radioactive isotope data have been used to investigate the source of recharge and the age of the shallow groundwater system within the southern voltaian sedimentary basin svsb of ghana as part of an on going groundwater development project the tritium concentrations in the groundwater samples are very low and range from less than 1 7 2 t u while measured 14c content ranges from 43 to 108 modern carbon the tritium concentration of rainfall ranges from less than 1 4 t u the 18o values of groundwater samples range from 4 2 to 2 6 while the d values range from 21 to 10 stable isotopic data of the groundwater samples lie either on or close to the global meteoric water line gmwl on the d 18o plot and indicate that the shallow groundwater in the area is derived from meteoric water that has undergone no significant degree of kinetic evaporation during recharge no indication of paleo recharge can be inferred from the 18o and 2h composition of the groundwater current tritium concentration in the groundwater is generally low however it proved useful in the qualitative identification of modern recharge radiocarbon deduced ages range from about b p to modern and indicate young recharge to the shallow groundwater system

geochemical studies of feldspathic fragmental breccias and the nature of north ray crater ejecta major and trace element analyses of clasts and matrix from feldspathic fragmental breccias show that these breccias are not all alike but vary widely in their bulk compositions and clast assemblages these studies together with analyses of other north ray crater large rocks reveal the major components to be anorthosites ferroan anorthositic norites magnesian granulites feldspathic melt rocks and vha impact melts the ferroan anorthositic norites are important lunar crustal rocks identified here for the first time the kreepy vha melts are found to be much more important in north ray crater ejecta than was previously assumed sodic ferrogabbro is an important minor component the compositional characteristics of bulk breccias and feldspathic melt rocks are modeled quantitatively as mixtures of two to five components anorthosites ferroan anorthositic norites magnesian granulites sodic ferrogabbros and vha melt rocks breccia 67455 is unique in consisting wholly of ferroan kreep free components

understanding recharge in soil groundwater systems in high loess hills on the loess plateau using isotopic data abstract the topography on the eastern and western sides of the liupan mountains northwestern china is characterized by hilly and gully loess deposits with elevations above 1000 m this study aims to uncover the mechanisms governing loess groundwater and soil water recharge in these relatively arid to semiarid higher loess hills on the basis of temporal soil profiles the results show that during the four monitoring periods the distinct variations of soil water and cl contents in soil water at different times in the upper parts of loess profiles particularly the increasing water content after the rainy season above 7 5 m indicate that temporal precipitation can at least infiltrate to 7 5 m in depth these variations attenuate as depth increases discernable variations in 18 o and 2 h values in soil water can also be identified at different times and even in deeper parts of the soil profiles however based on the average values in the steady state hydrologic layer ssl in the soil profiles very small temporal variations in average 18 o and 2 h values in the soil water in the ssl are observed if the analytical uncertainties of 2 h and 18 o are considered the 18 o and 2 h values in groundwater show relatively similar temporal fluctuations as the average values of soil water in the ssl at the same times they are also close to the local weighted average annual precipitation groundwater sampled in may 2013 revealed elevated tritium concentrations in both the monitoring well and the springs or wells the monitoring well displays a lower tritium isotope content 2 26 tu and others show higher contents in lower areas the radio carbon 14 isotope in the monitoring well also shows a lower content of approximately 25 95 pmc thus it can be inferred that in a general year temporal precipitation can rapidly infiltrate and reach the depth below 7 5 m of the loess profile through various preferential conduits preventing the water from evaporating near the surface then the soil water slowly percolates downwards mimicking a piston like flow and finally recharges groundwater these dual flow modes that exist inside loess deposits are the main mechanisms that maintain soil water and relatively abundant groundwater resources

calcium rich brines and other hydrothermal fluids in fluid inclusions from plutonic rocks oceanographer transform mid atlantic ridge abstract fluid inclusions in metagabbro plagiogranite and epidosite from the oceanographer transform mid atlantic ridge were investigated using microthermometric measurements and laser raman spectroscopy inclusions in quartz reveal the presence of a high salinity average 40 wt nacl cacl 2 high temperature 340 c calcium rich na ca about 1 by weight fluid in metagabbro and plagiogranite at room temperature these fluids bear a halite daughter crystal and may also contain small crystals of calcite titanite and hematite a low density vapor rich fluid bearing a small amount of co 2 is closely associated with the briney fluids in one sample all samples contain a population of high temperature 150 to 400 c aqueous liquid dominated fluid inclusions commonly of secondary origin having seawaterlike salinity 3 to 8 wt nacl equivalent we conclude that the calcium rich brines are produced by a combination of two processes fluid phase separation and segregation of brines from vapor prior to trapping to generate the high salinities and extensive fluid mafic rock interaction at low water rock ratio to promote the calcium enrichment later introduction along microfractures of low salinity modified seawater at high water rock ratio is recorded by the secondary fluid inclusions the chemical complexity and association with co 2 may indicate that there is a magmatic component to the brines in addition to a seawater source differences between the oceanographer transform brines and those reported in previous studies of oceanic and ophiolite samples are attributed to variations in the degree of water rock interaction the host rock lithology and the influence of a magmatic fluid component

magmatic salt melt and vapor extreme fluids forming porphyry gold deposits in shallow subvolcanic settings the recently discovered biely vrch deposit in the western carpathian magmatic arc is the most extreme example of a porphyry gold deposit being practically free of copper molybdenum or any other sulfide minerals microanalytical data on fluid inclusions in quartz veinlets including a characteristic type of banded veinlets show that this deposit formed from nearly anhydrous fe k na cl salt melts containing 10 ppm au coexisting with hydrous vapor of very low density this exceptional fluid evolution required an fe rich dioritic source magma that was emplaced at shallow subvolcanic depth 3 5 km directly exsolving a hypersaline liquid and magmatic vapor at high temperature 850 c during ascent to the level of the porphyry intrusion 0 5 1 km fluid expansion at high temperature but low pressure led to halite precipitation and further water loss to the vapor generating an increasingly fe k rich salt melt that transported high concentrations of au but negligible cu into the fractured porphyry stock the low sulfur fugacity resulting from fluid expansion suppressed precipitation of sulfide explaining the gold only enrichment in this globally recurring but rare type of gold ore

stable isotopic composition of precipitation in the semi arid north central portion of the us great plains abstract where data are available hydrologic studies may use stable oxygen and hydrogen isotopes to investigate groundwater surface water interaction groundwater recharge and advective diffusive transport to estimate groundwater ages or to unravel paleohydrology such studies require that the isotopic composition of precipitation be known as precipitation is a major input to groundwater and surface water systems oxygen 18 18 o and deuterium 2 h data for precipitation are lacking for the semi arid portion of the north central great plains of the us and thus there is need to establish additional meteoric water lines as isotope input functions across the region as well as to develop better understanding of the isotopic climate linkages that control oxygen and hydrogen isotope ratios in precipitation this study examines the 18 o and 2 h composition of precipitation for a representative site near north platte nebraska in the semi arid north central great plains during the years 1989 through 1994 oxygen 18 values range from 30 5 to 1 7 deuterium values range from 228 to 11 yearly arithmetic mean values for the north platte station are 9 8 and 71 respectively weighted yearly means for 18 o and 2 h over the 6 year period were 9 6 and 69 respectively north platte values show a strong isotopic enrichment between winter and summer precipitation and a strong 18 o t correlation r 2 0 845 for mean monthly values of 0 54 per degree celsius the local meteoric water line for the site is 2 h 7 66 18 o 4 96

geology mineralization fluid inclusion and stable isotope characteristics of the sinyukhinskoe cu au skarn deposit russian altai sw siberia abstract the sinyukhinskoe deposit 100 t au with average 9 2 g t au is situated in the altaid orogenic system and is part of the regional system of devonian carboniferous cu au to au cu porphyry skarn and other deposits productive plutonic suites were emplaced in a devonian subduction related continental magmatic arc setting with its further evolution toward a late and post collisional environment in the late devonian carboniferous the deposit is related to a magnetite series i type multiphase pluton with the evolution of the intrusive phases from early gabbroic through diorite granodiorite to the late granitic phases the igneous rocks belong to medium k calc alkaline series or are transitional from medium to high k calc alkaline varieties prior to granitic phases this evolution was interrupted by the intrusion of intramineral high k mafic dikes exhibiting a shoshonitic affinity the deposit is characterized by the development of abundant andradite rich garnet and wollastonite in prograde and retrograde skarns locally together with magnetite and bornite the subsequent propylitic epidote chlorite amphibole albite calcite quartz locally with clinozoisite and prehnite alteration assemblages bear more intense cu mineralization chalcopyrite bornite locally tennantite and high fineness 940 910 native gold later phyllic quartz sericite to quartz sericite chlorite alteration assemblages comprise the most intense intermediate fineness 910 880 native gold and cu bornite chalcocite mineralization that is followed by low fineness 820 760 native gold and telluride minerals the retrograde skarn was formed from a high salinity 22 23 wt nacl eq hot 450 50 c high pressure 2 5 0 5 kbar homogenous magmatic hydrothermal fluid under its possible direct separation from crystallizing magma after intrusion of intramineral mafic dikes propylitic alteration assemblages were formed from a moderate salinity 15 18 wt nacl eq homogenous aqueous fluid at the temperatures of 380 400 c this fluid could be supplied by crystallizing magma with its further mixing with heated meteoric waters fluid inclusions in phyllic alteration minerals indicate a new influx of homogenous high salinity 18 wt nacl 22 wt kcl 10 wt cacl2 high pressure 1 3 0 1 kbar aqueous chloride fluid at lower 280 c temperatures elevated bi hg te contents as well as 34s values close to meteorite standard 0 1 5 suggest at least partial fluid sourcing from a mantle derived magma at the phyllic alteration stage

accurate and precise quantification of major and trace element compositions of calcic sodic fluid inclusions by combined microthermometry and la icpms analysis abstract determination of absolute trace element concentrations in fluid inclusions using laser ablation la icpms requires an internal standard i e the concentration of one element must be independently known from independent observation microthermometric determination of the last melting temperature of ice hydrohalite or halite is routinely used to calculate apparent salinities in wt nacl equivalent using phase relations in the binary h 2 o nacl system to estimate na concentration calculating the concentrations of all other elements requires an empirical correction if additional salt concentrations are of similar magnitude as that of nacl if cacl 2 is the main additional salt component as in many low temperature basin and basement brines absolute na concentrations wt nacl abs can be obtained by observing two melting temperatures hydrohalite and either ice or halite uniquely defining the major element composition of the fluid in the ternary model system h 2 o nacl cacl 2 and allowing na to be used as internal standard for quantifying all minor and trace elements test results for a range of compositions show that calcium concentration can be determined more precisely by microthermometry than by la icpms analysis but that both methods agree within error the combined approach of microthermometry and la icpms analysis described here permits reliable quantification of major ca na as well as trace element concentrations in sodic calcic brine inclusions even in ca rich host minerals such as fluorite or ca bearing carbonates

chronology geochemistry and petrology of a ferroan noritic anorthosite clast from descartes breccia 67215 clues to the age origin structure and impact history of the lunar crust the petrology major and trace element geochemistry and nd ar sr isotopic compositions of a ferroan noritic anorthosite clast from lunar breccia 67215 have been studied in order to improve our understanding of the composition age structure and impact history of the lunar crust the clast designated 67215c has an unusually well preserved igneous texture mineral compositions are consistent with classification of 67215c as a member of the ferroan anorthositic suite of lunar highlands rocks but the texture and mineralogy show that it cooled more rapidly and at shallower depths than did more typical ferroan anorthosites fans incompatible trace element concentrations are enriched in 67215c relative to typical fans but diagnostic signatures such as ti sm sc sm plagiophile element ratios and the lack of zr hf and nb ta fractionation show that this cannot be due to the addition of kreep alternatively 67215c may contain a greater fraction of trapped liquid than is commonly present in lunar fans 147sm 143nd isotopic compositions of mineral separates from 67215c define an isochron age of 4 40 0 11 gyr with a near chondritic initial 143nd of 0 85 0 53 the 40ar 39ar composition of plagioclase from this clast records a post crystallization thermal event at 3 93 0 08 gyr with the greatest contribution to the uncertainty in this age deriving from a poorly constrained correction for lunar atmosphere 40ar rb sr isotopic compositions are disturbed probably by the same event recorded by the ar isotopic compositions trace element compositions of fans are consistent with crystallization from a moderately evolved magma ocean and do not support a highly depleted source composition such as that implied by the positive initial 143nd of the ferroan noritic anorthosite 62236 alternatively the nd isotopic systematics of lunar fans may have been subject to variable degrees of modification by impact metamorphism with the plagioclase fraction being more strongly affected than the mafic phases 147sm 143nd isotopic compositions of mafic fractions from the 4 ferroan noritic anorthosites for which isotopic data exist 60025 62236 67016c 67215c define an age of 4 46 0 04 gyr which may provide a robust estimate for the crystallization age of lunar ferroan anorthosites

extreme chemical heterogeneity of granite derived hydrothermal fluids an example from inclusions in a single crystal of miarolitic quartz magma derived fluids are important in geologic processes e g metal sequestration and ore deposition but are intrinsically transient samples of magmatic fluids represented by fluid inclusions in a single zoned quartz crystal from a miarolitic cavity within a porphyritic leucogranite hosting the industrialnoe tin deposit northeastern russia were studied by using modern in situ analytical methods laser raman spectroscopy proton induced x ray emission the fluid inclusions are either dominated by vapor or by complex multiphase brines the inclusions within a given trapping plane have similar phase relationships however there are significant variations between inclusions in different healed fractures phase and chemical compositions of individual brine inclusions demonstrate significant compositional heterogeneity in terms of absolute element concentrations and ratios of high temperature magmatic fluids accumulated in the miarolitic cavity this finding suggests that fluids leaving a crystallizing magma may have variable initial compositions that are subsequently modified by reactions with the rocks while the fluid is in transit to a miarolitic cavity as well as by processes in the cavity such as mixing crystallization and boiling the inferred chemical diversity and fractionation of granite derived fluids at near magmatic conditions imply that fluids entering a cooler hydrothermal system are extremely complex and their metallogenic signature may differ from that of related ore deposits

synthetic fluid inclusions xx critical ptx properties of h2o fecl2 fluids abstract iron chloride is a common and abundant component in hydrothermal fluids in many geologic environments yet the thermodynamic and ptx properties of fecl2 bearing aqueous fluids are poorly known in this study we have used the synthetic fluid inclusion technique to characterize the ptx conditions along the critical curve of the system h2o fecl2 for a given temperature or salinity the critical pressure in the h2o fecl2 system is lower than that in the h2o nacl system in contrast the critical curves of aqueous solutions of other divalent cation chlorides such as mgcl2 and cacl2 are at higher pressure than that of nacl solutions of equivalent temperature or salinity the results of this study provide the first quantitative constraints on the ptx extent of liquid vapor immiscibility for fecl2 rich fluids owing to the low pressure along the critical curve compared to other common aqueous chloride systems immiscibility of fecl2 rich fluids appears to be limited to relatively low pressures or relatively shallow levels in the crust compared to other saline hydrothermal fluids

seasonal bias in the formation and stable isotopic composition of pedogenic carbonate in modern soils from central new mexico usa in order to better calibrate pedogenic carbonate as a proxy for past environments we compared the stable isotopic composition of soil co 2 soil water and pedogenic carbonate in young soils from central new mexico usa seasonal changes in the 13 c value of soil co 2 the 18 o value of soil water and the soil temperature were monitored to establish the timing of isotopic equilibrium with the carbonate calcite solubility was calculated from measured temperatures and co 2 concentrations in the soil this approach allowed us to determine the conditions associated with pedogenic carbonate formation carbon isotope equilibrium oxygen isotope equilibrium and minimum calcite solubility all occurred simultaneously during warm dry conditions in may 2008 when soil co 2 concentrations were low it is therefore concluded that pedogenic carbonate forms during warm dry periods and does not record mean growing season conditions as typically assumed the seasonal bias in pedogenic carbonate formation may explain the occurrence of pedogenic carbonate in monsoon climates and its absence in regions where annual precipitation is more uniformly distributed the implications of the seasonal bias for stable isotope based paleoenvironmental reconstructions are that paleoelevations may have been previously over or underestimated paleoatmospheric co 2 concentrations likely have been signifi cantly overestimated and pedogenic carbonate provides a c 4 biased record of paleovegetation especially in dry soils

from evaporated seawater to uranium mineralizing brines isotopic and trace element study of quartz dolomite veins in the athabasca system abstract stable isotope o h c radiogenic isotope sr nd and trace element analyses have been applied to quartz dolomite veins and their uranium u bearing fluid inclusions associated with proterozoic unconformity related uo 2 uraninite ores in the athabasca basin canada in order to trace the evolution of pristine evaporated seawater towards u mineralizing brines during their migration through sediments and basement rocks fluid inclusion data show that quartz and dolomite have precipitated from brines of comparable chemistry excepted for relatively small amounts of co 2 found in dolomite hosted fluid inclusions however 18 o values of quartz veins 18 o 11 to 18 and dolomite veins 18 o 13 to 24 clearly indicate isotopic disequilibrium between quartz and dolomite hence it is inferred that this isotopic disequilibrium primarily reflects a decrease in temperature between the quartz stage 180 c and the dolomite stage 120 c the 13 c values of co 2 dissolved in dolomite hosted fluid inclusions 13 c 30 to 4 and the 13 c values of dolomite 13 c 23 5 to 3 5 indicate that the co 2 dissolved in the mineralizing brines originated from brine graphite interactions in the basement the resulting slight increase in the fluid partial pressure of co 2 p co 2 may have triggered dolomite precipitation instead of quartz 18 o values of quartz veins and previously published 18 o values of the main alteration minerals around the u ores illite chlorite and tourmaline show that quartz and alteration minerals were isotopically equilibrated with the same fluid at 180 c the ree concentrations in dolomite produce paas normalized patterns that show some similarities with that of uo 2 and are clearly distinct from that of the other main ree bearing minerals in these environments monazite zircon and aluminum phosphate sulfate aps minerals the radiogenic isotope compositions of dolomite 87 sr 86 sr i 0 7053 to 0 7161 and e nd t 8 8 to 20 3 differ from one deposit to another reflecting both heterogeneity in the basement geology and variable preservation of the original composition of brines the previously published 87 sr 86 sr i and e nd t values of uo 2 compare with the most evolved dolomites i e dolomites precipitated from brines that exchanged the most with the basement this reinforces a close genetic link between dolomites and uo 2 deposition and implies that uo 2 deposition occurred in a cooling system during the transition from quartz to dolomite formation the 18 o and d values of the mineralizing brines 18 o 1 to 8 and d 150 to 50 are considerably shifted from that of their theoretical original values acquired during evaporation of seawater 18 o 3 and d 40 the positive 18 o shift is explained by protracted fluid rock interaction within the basin and basement rocks the negative d shift is attributed to incomplete mixing between the u mineralizing brines and low d water this low d water was likely produced during the abiogenic synthesis of bitumen by fisher tropsch like reactions involving co 2 derived from brine graphite interaction in the basement and radiolytic h 2 the resulting low d brines have been equilibrated with alteration minerals this may explain why some alteration minerals yield anomalously low d values whose significance has long been debated

geology and fluid characteristics of the ulu sokor gold deposit kelantan malaysia implications for ore genesis and classification of the deposit abstract the ulu sokor gold deposit is one of the most famous and largest gold deposits in malaysia and is located in the central gold belt this deposit consists of three major orebodies that are related to ns and ne striking fractures within fault zones in permian triassic meta sedimentary and volcanic rocks of the east malaya block the faulting events represent different episodes that are related to each orebody and are correlated well with the mineralogy and paragenesis the gold mineralization consists of quartz dominant vein systems with sulfides and carbonates the hydrothermal alteration and mineralization occurred during three stages that were characterized by i silicification and brecciation ii carbonatization sericitization and chloritization and iii quartz carbonate veins fluid inclusions in the hydrothermal quartz and calcite of the three stages were studied the primary co 2 ch 4 h 2 o nacl fluid inclusions in stage i are mostly related to gold mineralization and display homogenization temperatures of 269 389 c salinities of 2 77 11 89 wt nacl equivalent variable co 2 contents typically 5 29 mol and up to 15 mol ch 4 in stage ii gold was deposited at 235 398 c from a co 2 ch 4 h 2 o nacl fluid with a salinity of 0 83 9 28 wt nacl equivalent variable co 2 contents typically 5 63 mol and up to 4 mol ch 4 the 18 o h 2 o and d values of the ore forming fluids from the stage ii quartz veins are 4 5 to 4 8 and 44 to 42 respectively and indicate a metamorphic hydrothermal origin oxygen fugacities calculated for the entire range of t p x co 2 conditions yielded log f o 2 values between 28 95 and 36 73 for stage i and between 28 32 and 39 18 for stage ii these values indicate reduced conditions for these fluids which are consistent with the mineral paragenesis fluid inclusion compositions and isotope values the presence of daughter mineral bearing aqueous inclusions is interpreted to be a magmatic signature of stage iiia combined with the oxygen and hydrogen isotopic compositions 18 o h 2 o 6 8 to 11 9 d 77 to 62 these inclusions indicate that the initial fluid was likely derived from a magmatic source in stage iiib the gold was deposited at 263 to 347 c from a co 2 ch 4 h 2 o nacl fluid with a salinity of 5 33 to 11 05 wt nacl equivalent variable co 2 contents typically 9 15 mol and little ch 4 the oxygen and hydrogen isotopic compositions of this fluid 18 o h 2 o 8 1 to 8 8 d 44 to 32 indicate that it was mainly derived from a metamorphic hydrothermal source the co 2 h 2 o ch 4 nacl fluids that were responsible for gold deposition in the stage iiic veins had a wide range of temperatures 214 483 c salinities of 1 02 to 21 34 wt nacl equivalent variable co 2 contents typically 4 53 mol and up to 7 mol ch 4 the oxygen and hydrogen isotopic compositions 18 o h 2 o 8 5 to 9 8 d 70 to 58 were probably acquired at the site of deposition by mixing of the metamorphic hydrothermal fluid with deep seated magmatic water and then evolved by degassing at the site of deposition during mineralization the log f o 2 values from 28 26 to 35 51 also indicate reduced conditions for this fluid in stage iiic moreover this fluid had a near neutral ph and 34 s values of h 2 s of 2 32 to 0 83 which may reflect the derivation of sulfur from the subducted oceanic lithospheric materials the three orebodies represent different gold transportation and precipitation models and the conditions of ore formation are related to distinct events of hydrothermal alteration and gold mineralization the gold mineralization of the ulu sokor deposit occurred in response to complex and concurrent processes involving fluid immiscibility fluid rock reactions and fluid mixing however fluid immiscibility was the most important mechanism for gold deposition and occurred in these orebodies which have corresponding fluid properties structural controls geologic characteristics tectonic settings and origins of the ore forming matter these characteristics of the ulu sokor deposit are consistent with its classification as an orogenic gold deposit while some of the veins are genetically related to intrusions

fluorapatite monazite allanite relations in the grangesberg apatite iron oxide ore district bergslagen sweden fluorapatite monazite xenotime allanite mineralogy petrology and textures are described for a suite of kiruna type apatite iron oxide ore bodies from the grangesberg mining district in the bergslagen ore province south central sweden fluorapatite occurs in three main lithological assemblages these include 1 the apatite iron oxide ore bodies 2 breccias associated with the ore bodies which contain fragmented fluorapatite crystals and 3 the variably altered host rocks which contain sporadic isolated fluorapatite grains or aggregates that are occasionally associated with magnetite in the silicate mineral matrix fluorapatite associated with the ore bodies is often zoned with the outer rim enriched in y ree compared to the inner core it contains sparse monazite inclusions in the breccia fluorapatite is rich in monazite ce xenotime y inclusions especially in its cores along with reworked larger monazite grains along fluorapatite and other mineral grain rims in the host rocks a small subset of the fluorapatite grains contain monazite xenotime inclusions while the large majority are devoid of inclusions overall these monazites are relatively poor in th and u allanite ce is found as inclusions and crack fillings in the fluorapatite from all three assemblage types as well as in the form of independent grains in the surrounding silicate mineral matrix in the host rocks the apatite iron oxide ore bodies are proposed to have an igneous subvolcanic origin potentially accompanied by explosive eruptions which were responsible for the accompanying fluorapatite rich breccias metasomatic alteration of the ore bodies probably began during the later stages of crystallization from residual magmatically derived hcl and h2so4 bearing fluids present along grain boundaries this was most likely followed by fluid exchange between the ore and its host rocks both immediately after emplacement of the apatite iron oxide body and during subsequent phases of regional metamorphism and deformation