Local Fluids Research Articles

Hydrothermal alteration of late‐ to post‐tectonic Lyon Mountain Granitic Gneiss, Adirondack Mountains, New York: Origin of quartz–sillimanite segregations, quartz–albite lithologies, and associated Kiruna‐type low‐Ti Fe‐oxide deposits

AbstractQuartz–sillimanite segregations, quartz–albite lithologies (Ab95–98), and Kiruna‐type low‐Ti iron‐oxide deposits are associated with late‐ to post‐tectonic (c. 1055 Ma) leucogranites of Lyon Mountain Gneiss (LMG) in the Adirondack Mountains, New York State. Most recent interpretations of these controversial features, which are global in occurrence, favour hydrothermal origins in agreement with results presented here.Field relations document that quartz–sillimanite veins and nodules cut, and therefore post‐date, emplacement of host LMG leucogranites. Veins occur in oriented fracture networks, and aligned trains of nodules are interpreted as disrupted early veins. Late dykes of leucogranite cut veins and nodules demonstrating formation prior to terminal magmatism. Veins and nodules consist of sillimanite surrounded by quartz that commonly embays wall‐rock feldspar indicating leaching of Na and K from LMG feldspar by acidic hydrothermal fluids. Subsequent, and repeated, ductile flow disrupted earlier veins into nodular fragments but produced little grain shape fabric.Geochemical and petrographic studies of quartz–albite rock indicate that it formed through metasomatic replacement (albitization) of LMG microperthite by sodic hydrothermal fluids that resulted in diagnostic checkerboard albite. Low‐Ti iron‐oxide ores are commonly associated with the quartz–albite sub‐unit, and it is proposed that hydrothermal fluids related to albitization transported Fe as well. The regional extent of sodic alteration suggests large quantities of surface‐derived hydrothermal fluids. Fluid inclusion and oxygen isotope data are consistent with high temperature, regionally extensive fluids consisting primarily of evolved surface‐derived brines enriched in Na and Cl. Quartz–sillimanite veins and nodules, which are significantly more localised phenomena and require acidic fluids, were most likely formed from local magmatic fluids in the crystallizing carapaces of LMG plutons.

He, Ne and Ar isotope compositions of fluid inclusions in hydrothermal sulfides from the TAG hydrothermal field Mid-Atlantic Ridge

Helium, rieon and argon isotope compositions of fluid inclusions have been measured in hydrothermal sulfide samples from the TAG hydrothermal field at the Mid-Atlantic Ridge. Fluid-inclusion He-3/He-4 ratios are 2.2-13.3 times the air value (Ra), and with a mean of 7.2 Ra. Comparison with the local vent fluids (He-3/He-4=7.5-8.2 Ra) and mid-ocean ridge basalt values (He-3/He-4=6-11 Ra) shows that the variation range of He-3/He-4 ratios from sulfide-hosted fluid inclusions is significantly large. Values for Ne-20/Ne-22 are from 10.2 to 11.4, which are significantly higher than the atmospheric ratio (9.8). And fluid-inclusion Ar-40/Ar-36 ratios range from 287 to 359, which are close to the atmospheric values (295.5). These results indicate that the noble gases of fluid inclusions in hydrothermal sulfides are a mixture of mantle- and seawater-derived noble gases; the partial mantle-derived components of trapped hydrothermal fluids may be from the lower mantle; the helium of fluid inclusions is mainly from upper mantle; and the Ne and Ar components are mainly from seawater.

Fluid history related to the Alpine compression at the margin of the south-Pyrenean Foreland basin: the El Guix anticline

The El Guix anticline is the southernmost structure of the south-Pyrenean fold-and-thrust belt (NE Spain). Compressional activity in the area represents the latest stages of Alpine compressional tectonics and affects the Upper Eocene–Oligocene fluvio-lacustrine deposits overlying an evaporite sequence. The evolution pattern of the fractures containing calcite cement consists of three stages of microfractures which reflect the evolution of the structure and the relationships between fluids and thrust development. In each fracture, deformation started with a network of discontinuous microfractures which acted as traps for local meteoric fluids (stage 1). During the second stage, dilatant thrust faults serving as the conduit for both evolved meteoric ascending and local meteoric fluids were developed. Migration of fluids through the thrusts was multiepisodic. After the precipitation of cements in microfracture stage 2, the thrusts were practically occluded by calcite cements, acting as fluid barriers and dividing the structure into different hydrological compartments. The last stage of microfracture (stage 3) is attributed to a younger phase, where the circulation of fluids concerned only meteoric fluids and the previously formed fractures acted as barriers to fluid circulation. Meteoric fluids, with high Fe/Mn and Fe/Mg ratios, without Na and Sr, enriched with 13C and with low 87Sr/ 86Sr with respect to their host rock were widely distributed in the structure throughout all its evolution, within a relatively open palaeohydrological system. Evolved meteoric fluids, with lower Fe/Mn and Fe/Mg ratios, with Na and Sr, depleted in 13C and with high 87Sr/ 86Sr with respect to their host rock were only present during thrust faults development (stage 2) within a relatively closed palaeohydrological system. The underlying evaporites acted as the lower boundary of the aquifer. Comparison with older thrust fronts of the same system reveals that the Pyrenean fold-and-thrust belt and its deformed southern foreland basin were compartmentalised hydrologically in time and space. During the early Eocene, when the thrust front affected soft-sediment in the Ainsa basin, the thrust faults were dominated by a medium scale fluid flow. The fluids in the basin were basically formation fluids derived from Eocene marine waters trapped in the underlying Eocene marls, although influences of meteoric waters were also present. During the middle Eocene, coeval with the Gavarnie thrust emplacement, the thrust fault was dominated by a medium scale fluid flow. The fluid was basically a hypersaline Sr-rich brine stored within Triassic redbeds. No evidence of a significant input of either surface or metamorphic fluids during thrusting was found. During the same period, in the crystalline basement of the central Pyrenees the thrust faults were dominated by a large scale fluid flow mainly derived from the underlying silicate rocks as a result of metamorphic devolatilisation reactions. During the Oligocene, the most external part of the fold-and-thrust belt developed on top of a salt detachment horizon. The thrust front affected cemented continental materials of late Eocene–Oligocene age. At this moment, the thrusts were conduits for meteoric fluids arriving from the surface and also for evolved meteoric fluids migrating a short distance upwards after being in contact with the underlying evaporitic beds.

Ore-fluid evolution at the Getchell Carlin-type gold deposit, Nevada, USA

Minerals and fluid-inclusion populations were examined using petrography, microthermometry, quadrupole mass-spectrometer gas analyses and stable-isotope studies to characterize fluids responsible for gold mineralization at the Getchell Carlin-type gold deposit. The gold-ore assemblage at Getchell is superimposed on quartz-pyrite vein mineralization associated with a Late-Cretaceous granodiorite stock that intruded Lower-Paleozoic sedimentary rocks. The ore assemblage, of mid-Tertiary age, consists of disseminated arsenian pyrite that contains submicrometer gold, jasperoid quartz, and later fluorite and orpiment that fill fractures and vugs. Late ore-stage realgar and calcite enclose ore-stage minerals. Pre-ore quartz trapped fluids with a wide range of salinities (1 to 21 wt.% NaCl equivalent), gas compositions (H2O, CO2, and CH4), and temperatures (120 to > 360°C). Oxygen- and hydrogen-isotope ratios indicate that pre-ore fluids likely had a magmatic source, and were associated with intrusion of the granodiorite stock and related dikes. Ore-stage jasperoid contains moderate salinity, aqueous fluid inclusions trapped at 180 to 220°C. Ore fluids contain minor CO2 and trace H2S that allowed the fluid to react with limestone host rocks and transport gold, respectively. Aqueous inclusions in fluorite indicate that fluid temperatures declined to ∼ 175°C by the end of ore-stage mineralization. As the hydrothermal system collapsed, fluid temperatures declined to 155 to 115°C and realgar and calcite precipitated. Inclusion fluids in ore-stage minerals have high δDH2O and δ18OH2O values that indicate that the fluid had a deep source, and had a metamorphic or magmatic origin, or both. Late ore-stage fluids extend to lower δH2O values, and have a wider range of δ18OH2O values suggesting dilution by variably exchanged meteoric waters. Results show that deeply sourced ore fluids rose along the Getchell fault system, where they dissolved carbonate wall rocks and deposited gold-enriched pyrite and jasperoid quartz. Gold and pyrite precipitated together as H2S in the ore fluids reacted with iron in the host rocks. As ore fluids mixed with local aquifer fluids, ore fluids became cooler and more dilute. Cooling caused precipitation of ore-stage fluorite and orpiment, and late ore-stage realgar. Phase separation and/or neutralization of the ore fluid during the waning stages of the hydrothermal ore system led to deposition of late ore-stage calcite.

Comparison of the efficacy of University of Wisconsin solution and Newcastle organ perfusion fluid in the preservation of livers for transplantation

Abstract University of Wisconsin solution (UW) is now used widely for the preservation of livers for transplantation. However, the use of commercial solutions has added considerably to the cost. We were able to produce a local version of organ perfusion fluid (NOPF) incorporating all the constituents of UW except for the hydroxyethyl starch and adenosine. We compared graft outcome using NOPF with imported grafts perfused with commercial UW solution. The two recipient groups (15 patients each) were similar with respect to age and sex distribution, urgency of transplantation, regraft status and patient and graft survival. Postoperative duration of ventilation, dialysis requirements, peak bilirubin, peak ALT and lowest unsupported prothrombin time were also similar in both groups. In conclusion, local perfusion fluids based on UW can be produced without detriment to graft outcome with considerable financial savings. At our institution, this represents a reduction of 33 % in the cost of perfusion fluids.

PERIOPERATIVE PATTERN OF PERITONEAL INTERLEUKIN 8, TUMOUR NECROSIS FACTOR-α, AND GRANULOCYTE ELASTASE RELEASE IN HUMAN SECONDARY PERITONITIS

Cytokine levels during infection and sepsis have been extensively studied in the past. In contrast to the excellent data on tumour necrosis factor α (TNF-α), interleukin 8 (IL-8), and polymorphonuclear (PMN) granulocyte elastase (PMN-E) concentrations in blood, little is known about cytokine and PMN-E levels in tissue or local fluids like abdominal exudate in secondary, purulent peritonitis of man. Therefore, the authors studied perioperative intra-abdominal levels of TNF-α, IL-8 and PMN-E in 21 patients with severe purulent peritonitis. The average pre-operative levels of TNF-α were 694+239 pg/ml in exudate and 26±6 pg/ml in plasma, for IL-8 100±34 ng/ml and 0.7±0.5 ng/ml, and for PMN-E 68±14 μg/ml and 0.7±0.1 μg/ml, respectively. Standard surgical procedures reduced the intra-abdominal concentrations of cytokines and PMN-E to as low as one tenth of the pre-operative levels. Postoperatively, TNF-α and IL-8 levels recovered rapidly and pre-operative levels of IL-8 were reached again after 1 h and for TNF-α after 8 h. PMN-E concentration remained below the initial baseline within 8 h of observation. TNF-α concentration, but not IL-8 or PMN-E, depended on the microbiological load of the abdominal exudate (< or >103cfu/ml). There were no significant differences in the intra-abdominal or plasma levels of cytokines or PMN-E between survivors and non-survivors at any observation time.

Sr, C and O isotope systematics in the Pucará basin, central Peru

A combined Sr, O and C isotope study has been carried out in the Pucara basin, central Peru, to compare local isotopic trends of the San Vicente and Shalipayco Zn-Pb Mississippi Valley-type (MVT) deposits with regional geochemical patterns of the sedimentary host basin. Gypsum, limestone and regional replacement dolomite yield 87Sr/86Sr ratios that fall within or slightly below the published range of seawater 87Sr/86Sr values for the Lower Jurassic and the Upper Triassic. Our data indicate that the Sr isotopic composition of seawater between the Hettangian and the Toarcian may extend to lower 87Sr/86Sr ratios than previously published values. An 87Sr-enrichment is noted in (1) carbonate rocks from the lowermost part of the Pucara basin, and (2) different carbonate generations at the MVT deposits. This indicates that host rocks at MVT deposits and in the lower-most part of the carbonate sequence interacted with 87Srenriched fluids. The fluids acquired their radiogenic nature by interaction with lithologies underlying the carbonate rocks of the Pucara basin. The San Ramon granite, similar Permo-Triassic intrusions and their clastic derivatives in the Mitu Group are likely sources of radiogenic 87Sr. The Brazilian shield and its erosion products are an additional potential source of radiogenic 87Sr. Volcanic rocks of the Mitu Group are not a significant source for radiogenic 87Sr; however, molasse-type sedimentary rocks and volcaniclastic rocks cannot be ruled out as a possible source of radiogenic 87Sr. The marked enrichment in 87Sr of carbonates toward the lower part of the Pucara Group is accompanied by only a slight decrease in δ 18O values and essentially no change in δ 13C values, whereas replacement dolomite and sparry carbonates at the MVT deposits display a coherent trend of progressive 87Sr-enrichment, and 18O- and 13C-depletion. The depletion in 18O in carbonates from the MVT deposits are likely related to a temperature increase, possibly coupled with a 18O-enrichment of the ore-forming fluids. Progressively lower δ 13C values throughout the paragenetic sequence at the MVT deposits are interpreted as a gradually more important contribution from organically derived carbon. Quantitative calculations show that a single fluid-rock interaction model satisfactorily reproduces the marked 87Sr-enrichment and the slight decrease in δ 18O values in carbonate rocks from the lower part of the Pucara Group. By contrast, the isotopic covariation trends of the MVT deposits are better reproduced by a model combining fluid mixing and fluid-rock interaction. The modelled ore-bearing fluids have a range of compositions between a hot, saline, radiogenic brine that had interacted with lithologies underlying the Pucara sequence and cooler, dilute brines possibly representing local fluids within the Pucara sequence. The composition of the local fluids varies according to the nature of the lithologies present in the neighborhood of the different MVT deposits. The proportion of the radiogenic fluid in the modelled fluid mixtures interacting with the carbonate host rocks at the MVT deposits decreases as one moves up in the stratigraphic sequence of the Pucara Group.

Lead behaviour at the TAG hydrothermal vent field, 26°N, Mid-Atlantic Ridge

Samples of basaltic glass, hydrothermal vent fluids, hydrothermal plume particles, mound deposits and metalliferous sediments from the TAG hydrothermal field have been analysed. Local MORB has an isotopic composition of 208Pb/ 204Pb = 37.568, 207Pb/ 204Pb = 15.450, 206Pb/ 204Pb = 18.124 . Directly upon emission vent fluid contains 90 nmol kg −1 Pb with a molar Pb/Fe ratio of 1.5 × 10 −5. The high-temperature vent fluid has an isotopic composition of 208Pb/ 204Pb = 37.734, 207Pb/ 204Pb = 15.476, 206Pb/ 204Pb = 18.304 which is more radiogenic than MORB. Chalcopyrite, atacamite and oxides from the TAG mound also exhibit a slightly more radiogenic Pb isotopic composition than MORB which is suggestive of some seawater or sediment influence. Dissolved Pb concentrations decrease to ∼1 nmol kg −1 immediately above the vent because of sulfide precipitation. Particulate Pb behaves conservatively in the buoyant hydrothermal plume over dilutions of ∼ 1-0.1% of the endmember fluids with ambient seawater and Pb/Fe ratios are maintained. Since about 50% of the Fe is thought to be removed from the buoyant plume by fall-out of sulfides during this mixing, a similar proportion of Pb is similarly removed. The buoyant plume particles have non-radiogenic isotopic compositions ( 208Pb/ 204Pb = 37.734–37.943, 207Pb/ 204Pb = 15.497–15.525, 206Pb/ 204Pb = 18.176–18.463 ), intermediate between vent fluid and basalt, consistent with a dominant hydrothermal source and appear to be mainly associated with sulfides, although there is some evidence from Pb/Fe and 210Pb/Pb ratios that some uptake of Pb from seawater occurs. Sulfides are seen with Fe-oxide particles from the neutrally-buoyant plume. Pb isotope data for these particles fall within a field defined by local vent fluids, modern terrigenous Pb, and what is inferred to be local seawater. Hydrothermal sediments from TAG have a mean Pb/Fe ratio of 10.5 × 10 −5, which is within the range observed in neutrally-buoyant plume particles (9.0–29 × 10 −5) and TAG mound materials (1.3–26 × 10 −5) suggestive of a dual origin. Pb isotopic compositions can be explained by mixing between MORB and Quaternary terrigenous Pb, with some evidence of seawater alteration of mound material.

Pb isotopes of ore deposits in Trans-Pecos Texas and northeastern Chihuahua, Mexico; basement, igneous, and sedimentary sources of metals

Tertiary ore deposits and prospects in Trans-Pecos Texas and adjacent Mexico have Pb isotope ratios that indicate probable sources of metals. Sulfides from these deposits have a wide range of Pb isotope ratios: 206 Pb/ 204 Pb, 17.74 to 20.04; 207 Pb/ 204 Pb, 15.46 to 15.69; 208 Pb/ 204 Pb, 37.52 to 40.37. In part, this variability reflects derivation of Pb from contrasting basement and Tertiary igneous rocks across a major lithospheric boundary between the North American craton on the northwest and terranes accreted during the late Paleozoic Ouachita orogeny to the southeast. Precambrian basement and Tertiary igneous rocks northwest of a northeast-trending zone through Trans-Pecos Texas and Chihuahua, Mexico, are less radiogenic than Phanerozoic and Precambrian basement and Tertiary igneous rocks to the southeast.Although isotopic ratios from ore deposits and prospects in the region generally reflect basement type, steep arrays on 206 Pb/ 204 Pb versus 207 Pb/ 204 Pb diagrams from some deposits in the northwest basement province indicate mixing with additional, more radiogenic, sources of Pb. We infer that these sources are local sedimentary rocks or basinal fluids. Vein- and porphyry-type prospects hosted by igneous rocks show the least influence from these radiogenic sources. They have Pb isotope ratios that fall within the range of Pb isotope ratios of local Tertiary igneous rocks. In contrast, red-bed-hosted Ag-Cu-Pb deposits in the northwest, with no apparent igneous source of fluids, generally have relatively high 206 Pb/ 204 Pb and 207 Pb/ 204 Pb ratios, which are apparently inherited from their host sediments. Veins hosted by sedimentary rocks and high-temperature carbonate-hosted Ag-Pb-Zn deposits (manto, chimney, and skarn) have intermediate Pb isotope ratios that range between the lower 207 Pb/ 204 Pb igneous-hosted deposits and the higher 207 Pb/ 204 Pb sedimentary-hosted deposits. They appear to contain variable mixtures of Pb from mid-Tertiary igneous sources and sedimentary rocks. In the northwest basement province Ag-Pb-Zn deposits at Shafter, Texas, have low Pb isotope ratios derived from associated igneous rocks and indicative of underlying Precambrian crust with low 206 Pb/ 204 Pb and 207 Pb/ 204 Pb. Similar, but larger, deposits at Santa Eulalia, Chihuahua, contain a mixture of Pb from at least two sources. It appears that a low 207 Pb/ 204 Pb component associated with Tertiary igneous rocks and ultimately derived from Precambrian basement has mixed with a higher 207 Pb/ 204 Pb component derived from the sedimentary wall rock. Published fluid inclusion and S isotope studies also suggest that mixing of magmatic and sedimentary components is common in the genesis of high-temperature carbonate-hosted Ag-Pb-Zn deposits.

A mechanism for the formation of methane hydrate and seafloor bottom‐simulating reflectors by vertical fluid expulsion

Bottom‐simulating reflectors (BSR) are observed commonly at a depth of several hundred meters below the seafloor in continental margin sedimentary sections that have undergone recent tectonic consolidation or rapid accumulation. They are believed to correspond to the deepest level at which methane hydrate (clathrate) is stable. We present a model in which BSR hydrate layers are formed through the removal of methane from upward moving pore fluids as they pass into the hydrate stability field. In this model, most of the methane is generated below the level of hydrate stability, but not at depths sufficient for significant thermogenic production; the methane is primarily biogenic in origin. The model requires either a mechanism to remove dissolved methane from the pore fluids or disseminated free gas carried upward with the pore fluid. The model accounts for the evidence that the hydrate is concentrated in a layer at the base of the stability field, for the source of the large amount of methane contained in the hydrate, and for BSRs being common only in special environments. Strong upward fluid expulsion into the hydrate stability field does not occur in normal sediment depositional regimes, so BSRs are uncommon. Upward fluid expulsion does occur as a result of tectonic thickening and loading in subduction zone accretionary wedges and in areas where rapid deposition results in initial undercconsolidation. In these areas hydrate BSRs are common. The most poorly quantified aspect of the model is the efficiency with which methane is removed and hydrate is formed as pore fluids pass into the hydrate stability field. The critical boundary in the phase diagram between the fluid‐plus‐hydrate and fluid‐only fields is not well constrained. However, the amount of methane required to form the hydrate and limited data on methane concentrations in pore fluids from deep‐sea boreholes suggest very efficient removal of methane from rising fluid that may contain less than the amount required for free gas production. In most fluid expulsion regimes, the quantity of fluid moved upward to the seafloor is great enough to continually remove the excess chloride and the residue of isotope fractionation resulting from hydrate formation. Thus, as observed in borehole data, there are no large chloride or isotope anomalies remaining in the local pore fluids. The differences in the concentration of methane and probably of CO2 in the pore fluid above and below the base of the stability field may have a significant influence on early sediment diagenetic reactions.

Evaluation of the fluid-inclusion crushing-stage as an aid in exploration for mesothermal gold-quartz deposits

Case studies in the Wabigoon and Uchi Archaean greenstone belts of Canada demonstrate that the liquid CO 2-bearing fluid inclusions, which are diagnostic of mesothermal gold-quartz-carbonate-sulphide deposits, may be reliably and reproducibly detected in the field by crushing-stage analysis. The technique alone cannot distinguish veins of different ore grade in a given exploration terrain, but after preliminary crushing tests to assess the composition of local metamorphic fluids, samples from potentially auriferous mesothermal deposits may be inexpensively and unequivocally identified in the field. The most powerful application of the crushing-stage is in geochemical surveys of sediments in which diagnostic fluid inclusions in quartz may offer a much wider exploration target than the related gold anomaly. Unmistakable haloes of liquid CO 2-bearing fluid inclusions are rapidly detectable in the wall rocks surrounding mesothermal veins. The haloes are spatially as extensive as the alteration mineral assemblages, and thus in field situations where outcrop is sparse or highly weathered, crushing analysis may aid in targeting areas for more detailed exploration.

Dioctahedral Corrensite from Permian Red Beds, Lisbon Valley, Utah

AbstractRegularly interstratified chlorite/smectite (corrensite) occurs as grain coatings in marine and eolian sandstones of the Permian Cutler Formation in Lisbon Valley, Utah. Corrensite dominates the &lt;2-μm clay size fraction along with lesser amounts of regularly interstratified illite/smectite in bleached, permeable sandstones that are interbedded with smectite-dominated arkosic, red, laterally discontinuous fluvial sandstones. Chemical and X-ray powder diffraction analyses of the corrensites show them to be di/dioctahedral with 060 spacings of 1.501 to 1.508 Å and to contain significantly higher Al:Mg ratios than more common trioctahedral types. Calculated structural formulae are: corrensite, M0.6(Fe3+0.2Mg1.6Al4.6)(Al0.2Si7.8)O20(OH)10; illite/smectite, M1.5(Fe3+0.1Mg1.7Al2.8)(Al1.6Si6.4)O20(OH)4; and smectite, M0.9(Fe3+0.3Mg1.2Al2.8)(Al0.6Si7.4)O20(OH)4.Chemical similarity between the smectite and the corrensite and pervasive distribution of smectite in low-permeability shales and siltstones suggest that the smectite was a precursor of the corrensite. Three stages of mineral precipitation in the Cutler Formation have been recognized. Quartz precipitated early as grain overgrowths, followed by the formation of authigenic clay minerals, and later calcite cementation which destroyed much of the original rock fabric. Calculations show that aluminous corrensite was favored by elevated temperature (∼ 100°C), low pH, and low dissolved silica. Local hydrothermal fluids rising along the Lisbon fault apparently permeated the Cutler red bed section and precipitated the clay minerals. The assemblage corrensite + illite/smectite in the sandstones probably formed by interaction of formation fluids with smectite and an Al-bearing phase, such as K-feldspar or kaolinite.

Mechanism for pulmonary protection by lipopolysaccharide pseudomonas vaccine.

Recent studies in guinea pigs indicated that active vaccination with a cell wall-derived, lipopolysaccharide (LPS) pseudomonas vaccine confers specific protection against acute pneumonia. This study analyzed the immune mechanisms by which LPS pseudomonas vaccine offers local protection to the lung. Neither parenteral vaccination nor direct exposure of lung tissues to living Pseudomonas activated alveolar macrophages. However, serum opsonic activity that specifically enhanced phagocytosis of Pseudomonas by alveolar macrophages was significantly increased (P < 0.05) in vaccinated animals. Serum pseudomonas opsonins were heat-stable but were sensitive to reduction of macroglobulins by 2-mercaptoethanol. Within 3 hr after establishment of experimental pseudomonas pneumonia, a fourfold increase in local pseudomonas opsonins was found in bronchial fluids from vaccinated animals, presumably secondary to diffusion of serum proteins into local inflammatory fluids. Thus, Pseudomonas-specific opsonic antibody appears necessary to augment alveolar macrophage phagocytosis after LPS vaccination, and local vaccination of the respiratory tract is not required to provide adequate local pseudomonas opsonins during acute pneumonia.

D/H ratios, origins, and evolution of the ore-forming fluids for the Neogene veins and kuroko deposits of Japan

The delta D values of inclusion fluids from quartz and calcite of the Au-Ag vein deposits range from -48 to -72 per mil, showing a strong correlation with values of the local meteoric waters. The 18 O/ 16 O ratios of the ore fluids of quartz, the filling temperatures of the fluid inclusions, and the isotopic fractionation factor between quartz and water show only slight shifts from these values in meteoric water.The delta D values of ore fluids for the Cu-Pb-Zn vein deposits vary from -42 to -74, showing a wider scatter within a single orebody than for the Au-Ag vein deposits. A weak but definite correlation exists between the D/H ratios of local meteoric waters and ore fluids for late-stage ore minerals. The ore fluids for the Cu-Pb-Zn veins have a 2 to 9 per mil positive oxygen isotopic shift from the meteoric values. These results and calculations based on a new model of rock-water interaction indicate that ore fluids for the Au-Ag vein deposits and for the later stage mineralization of the Cu-Pb-Zn deposits evolved from local meteoric waters under low rock/water ratios. Conversely, the major stage of mineralization of the Cu-Pb-Zn vein deposits precipitated from meteoric hydrothermal solutions that could have evolved under high rock/water ratios; this stage has a much higher salinity than fluids of the later stage. The contribution of magmatic fluids could have ranged from 0 to 20 volume percent in the major stage.The delta D and delta 18 O values for the Kuroko ore solutions were -10 to -30 and -1.0 to +1.0, respectively, for deposits in the Hokuroku basins, northeast Honshu, and -30 to -50 and about -2, respectively, for the Iwami mine, southwest Honshu. These isotopic results, the salinity data, and the calculations on the effect of rock-water interactions indicate that the Kuroko ore solutions of the Hokuroku basins could have evolved from mixtures of sea water and meteoric water. A small amount of magmatic water may have been present. The close association of sulfates and Mg-chlorites in the Kuroko deposits is the direct result of the incorporation of sea water into submarine hydrothermal systems.This study shows that, contrary to the prevailing thought, the vein mineralization occurred under terrestrial environments and, thus, is younger (upper Miocene to Pliocene) than the Kuroko deposits. All the constituents of the vein ores were leached from the Tertiary country rocks by the meteoric hydrothermal circulation. Sulfur isotopic studies indicate that the sulfur came from Miocene sea-water sulfate trapped in the Tertiary sediments as dissolved sulfates in pore water or as anhydrite and gypsum. The lead isotope abundances, mineralogy, and chemistry of both the veins and the Kuroko deposits also are in accord with the present results. The close association of sulfates and Mg-chlorites in the Kuroko deposits is the direct result of the incorporation of sea water into submarine hydrothermal systems.

Determination of the sources and circulation paths of thermal fluids: the Abano region, northern Italy

Water samples from natural springs and artesian wells in the Abano region of northern Italy are characterized by anomalous temperatures and compositions. Concentrations of major components and oxygen isotopes in samples of these fluids have been interpreted in the context of the regional geologic environment, circulation of groundwaters, and reactions between rocks and circulating groundwaters. These considerations define sourceregions and pathlines of the groundwaters. Circulation of fluids in the Abano region is interpreted to be the result of meteoric water infiltration into outcrops of Permian and Mesozoic aquifers in the pre-Alps, which lie north of the Abano region. These aquifers have southerly dips and, therefore, extend under the Abano region at depths between 0.5 and 2.5 km. This aquifer geometry is conducive to forced convection both of aqueous ions derived from the evaporate, limestone and dolomite bearing formations, and of thermal energy along flow paths which extend from the outcrops in the sourceregions to depths of 2 km below the Abano region and upward along high angle faults to thermal springs. Local variation in compositions of water samples is consistent with the mixing of local meteoric waters and formation fluids that were ultimately derived from Alpine sources.