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  1. Book ; Conference proceedings ; Online: (Table T1) Bulk rock geochemistry of fresh lavas from ODP Leg 193 sites, PACMANUS field, supplementary data to: Miller, D Jay; Vanko, David A; Paulick, Holger (2006): Data report: Petrology and geochemistry of fresh, recent dacite lavas at Pual Ridge, Papua New Guinea, from an active, felsic-hosted seafloor hydrothermal system. In: Barriga, FJAS; Binns, RA; Miller, DJ; Herzig, PM (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 193, 1-31

    Miller, D Jay / Paulick, Holger / Vanko, David A

    2006  

    Abstract: Leg 193 was the fourth Ocean Drilling Program expedition focusing on understanding subseafloor hydrothermal systems. This program was the first to combine studies of the volcanology, structure, hydrology, mineralization, and microbiology of a subseafloor ...

    Abstract Leg 193 was the fourth Ocean Drilling Program expedition focusing on understanding subseafloor hydrothermal systems. This program was the first to combine studies of the volcanology, structure, hydrology, mineralization, and microbiology of a subseafloor hydrothermal system hosted by felsic rocks by coring at the PACMANUS hydrothermal field in the Manus Basin, Papua New Guinea. The study examines only the petrology and bulk rock and mineral chemistry of the freshest and most morphologically youthful lava flows recovered from the shallowest drill cores at the four sites occupied during Leg 193. There are subtle but distinct petrographic and geochemical variations between the closely spaced sites.
    Language English
    Dates of publication 2006-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Conference proceedings ; Online
    Note This dataset is supplement to doi:10.2973/odp.proc.sr.193.208.2006
    DOI 10.1594/PANGAEA.778980
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  2. Book ; Conference proceedings ; Online: Geochemical composition and atomic formulas of saponites, celadonites and carbonates from ODP Leg 168 sites, supplementary data to: Marescotti, Pietro; Vanko, David A; Cabella, Roberto (2000): From oxidizing to reducing alteration: mineralogical variations in pillow basalts from the east flank, Juan de Fuca Ridge 2000. In: Fisher, A; Davis, EE; Escutia, C (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 168, 1-18

    Marescotti, Pietro / Cabella, Roberto / Vanko, David A

    2000  

    Abstract: With this study, we investigate the mineralogical variations associated with the low-temperature (<100°C) alteration of normal tholeiitic pillow basalts varying in age from 0.8 to 3.5 Ma. Their alteration intensity varies systematically and is related to ...

    Abstract With this study, we investigate the mineralogical variations associated with the low-temperature (<100°C) alteration of normal tholeiitic pillow basalts varying in age from 0.8 to 3.5 Ma. Their alteration intensity varies systematically and is related to several factors, including (1) the aging of the igneous crust, (2) the increase of temperatures from the younger to the older sites, measured at the sediment/basement interface, (3) the local and regional variations in lithology and primary porosity, and (4) the degree of pillow fracturing. Fractures represent the most important pathways that allow significant penetration of fluids into the rock and are virtually the only factor controlling the alteration of the glassy rim and the early stages of pillow alteration. Three different alteration stages have been recognized: alteration of glassy margin, oxidizing alteration through fluid circulation in fracture systems, and reducing alteration through diffusion.
    All the observed mineralogical and chemical variations occurring during the early stages of alteration are interpreted as the result of the rock interaction with "normal," alkaline, and oxidizing seawater, along preferential pathways represented by the concentric and radial crack systems. The chemical composition of the fluid progressively evolves while moving into the basalt, leading to a reducing alteration stage, which is initially responsible for the precipitation of Fe-rich saponite and minor sulfides and subsequently for the widespread formation of carbonates. At the same time, the system evolved from being "water dominated" to being "rock dominated." No alteration effects in pillow basalts were observed that must have occurred at temperatures higher than those measured during Leg 168 at the basement/sediment interface (e.g., between 15° and 64°C).
    Language English
    Dates of publication 2000-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Conference proceedings ; Online
    Note This dataset is supplement to doi:10.2973/odp.proc.sr.168.006.2000
    DOI 10.1594/PANGAEA.788887
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  3. Book ; Conference proceedings ; Online: Geochemical composition of calcite and aragonite, and characteristics of hydrothermal fluids of ODP Leg 168 sites, supplementary data to: Yatabe, Autumn; Vanko, David A; Ghazi, Mohamad (2000): Petrography and chemical compositions of secondary calcite and aragonite in Juan de Fuca Ridge basalts altered at low temperature. In: Fisher, A; Davis, EE; Escutia, C (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 168, 1-12

    Yatabe, Autumn / Ghazi, Mohamad / Vanko, David A

    2000  

    Abstract: During Leg 168 a transect was drilled across the eastern flank of the Juan de Fuca Ridge in an area where the volcanic basement is covered by sediments of variable thickness. Samples of basement volcanic rocks were recovered from nine locations along the ...

    Abstract During Leg 168 a transect was drilled across the eastern flank of the Juan de Fuca Ridge in an area where the volcanic basement is covered by sediments of variable thickness. Samples of basement volcanic rocks were recovered from nine locations along the transect, where the basement sediment interface is presently heated to temperatures varying from 15° to 64°C. Altered rocks with secondary calcium carbonate were common at four of the sites, where present-day temperatures range from 38° to 64°C. Fluid inclusions in aragonite suggest that the mineral precipitated from an aqueous fluid of seawater salinity at temperatures well below 100°C.
    The chemical compositions of secondary calcite and aragonite were determined with both an electron microprobe and a laser-ablation inductively coupled plasma-mass spectroscopy (LA-ICP-MS) microprobe. These two techniques yielded consistent analyses of the same minor elements (Mg and Sr) in the same specimens. The combined results show that secondary aragonites contain very little Mg, Mn, Fe, Co, Ni, Cu, Zn, Rb, La, Ce, Pb, or U, yet they contain significant Sr. In contrast, secondary calcites contain significant Mg, Mn, Fe, Ni, Cu, Zn, and Pb, yet very little Co, Rb, Sr, La, Ce, or U. Secondary calcium carbonates provide subseafloor reservoirs for some minor and trace elements. Replacement of aragonite by calcite should result in a release of Sr, Rb, and Zn to solution, and it provides a sink for Mg, Mn, Ni, Cu, Zn, and Pb.
    Language English
    Dates of publication 2000-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Conference proceedings ; Online
    Note This dataset is supplement to doi:10.2973/odp.proc.sr.168.003.2000
    DOI 10.1594/PANGAEA.788893
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  4. Book ; Conference proceedings ; Online: Geochemical composition and atomic formulas of saponites, celadonites and clays from ODP Leg 168 sites, supplementary data to: Porter, Sean; Vanko, David A; Ghazi, Mohamad (2000): Major and trace element compositions of secondary clays in basalts altered at low temperature, eastern flank of the Juan de Fuca Ridge. In: Fisher, A; Davis, EE; Escutia, C (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 168, 1-9

    Porter, Sean / Ghazi, Mohamad / Vanko, David A

    2000  

    Abstract: A drilling transect across the sedimented eastern flank of the Juan de Fuca Ridge, conducted during Leg 168 of the Ocean Drilling Program, resulted in the recovery of samples of volcanic basement rocks (pillow basalts, massive basalts, and volcanic glass ...

    Abstract A drilling transect across the sedimented eastern flank of the Juan de Fuca Ridge, conducted during Leg 168 of the Ocean Drilling Program, resulted in the recovery of samples of volcanic basement rocks (pillow basalts, massive basalts, and volcanic glass breccias) that exhibit the effects of low-temperature hydrothermal alteration. Secondary clays are ubiquitous, with Mg-rich and Fe-rich saponite and celadonitic clays commonly accounting for several percent, and up to 10%-20% by volume. Present-day temperatures of the basement sites vary from 15° to 64°C, with the coolest site being about 0.8 Ma, and the warmest site being about 3.5 Ma. Whereas clays are abundant at sites that have been heated to present temperatures of 23°C and higher, the youngest site at 15°C has only a small trace of secondary clay alteration. Alteration increases as temperatures increase and as the volcanic basement ages.
    The chemical compositions of secondary clays were determined by electron microprobe, and additional trace element data were determined by both conventional nebulization inductively coupled plasma-mass spectroscopy (ICP-MS) and laser-ablation ICP-MS. Trioctahedral saponite and pyrite are characteristic of the interior of altered rock pieces, forming under conditions of low-oxygen fugacity. Dioctahedral celadonite-like clays along with iron oxyhydroxide and Mg-saponite are characteristic of oxidized haloes surrounding the nonoxidized rock interiors. Chemical compositions of the clays are very similar to those determined from other deep-sea basalts altered at low temperature. The variable Mg:Fe of saponite appears to be a systematic function both of the Mg:Fe of the host rock and the oxidation state during water-rock interaction.
    Language English
    Dates of publication 2000-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Conference proceedings ; Online
    Note This dataset is supplement to doi:10.2973/odp.proc.sr.168.004.2000
    DOI 10.1594/PANGAEA.788900
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  5. Book ; Conference proceedings ; Online: Geochemistry of vein rocks of ODP Hole 118-735B, supplementary data to: Vanko, David A; Stakes, Debra S (1991): Fluids in oceanic layer 3: evidence from veined rocks, Hole 735B, Southwest Indian Ridge. In: Von Herzen, RP; Robinson, PT; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 118, 181-215

    Vanko, David A / Stakes, Debra S

    1991  

    Abstract: Rock samples from Hole 735B, Southwest Indian Ridge, were examined to determine the principal vein-related types of alteration that occurred, the nature of fluids that were present, and the temperatures and pressures of these fluids. Samples studied ... ...

    Abstract Rock samples from Hole 735B, Southwest Indian Ridge, were examined to determine the principal vein-related types of alteration that occurred, the nature of fluids that were present, and the temperatures and pressures of these fluids. Samples studied included veined metagabbro, veined mylonitic metagabbro, felsic trondhjemite, and late-stage leucocratic diopside-bearing veins. The methods used were standard petrographic analysis, mineral chemical analysis by electron microprobe, fluid inclusion petrography and analysis by heating/freezing techniques and laser Raman microspectroscopy, and oxygen isotopic analyses of mineral separates.
    Alteration in lithologic Units I and II (above the level of Core 118-735B-3OR; approximately 140 meters below the seafloor) is dominated by hydration by seawater-derived fluids at high temperature, up to about 700?C, and low water/rock ratio, during and immediately after pervasive ductile deformation. Below Core 118-735B-30R, pervasive deformation is less common, and brittle veining and brecciation are the major alteration styles. Leucocratic centimeter-scale veins, often containing diopside and plagioclase, were produced by interaction of hot (about 500?C) seawater-derived fluid and gabbro. The water/rock ratio was locally high at the veins and breccia zones, but the integrated water/rock ratio for the lower part of the hole is probably low.
    Accessory hydrous magmatic or deuteric phases formed from magmatic volatiles in some gabbro and in trondhjemite. Most subsequent alteration was affected by fluids that were seawater-derived, based on isotopic and chemical analyses of minerals and analyses of fluid inclusions. Many early-generation fluid inclusions, associated with high-temperature veining, contain appreciable methane as well as saline water. The source of methane is unclear, but it may have formed as seawater was reduced during low water/rock interaction with ultramafic upper mantle or ultramafic and mafic layer 3.
    Temperatures of alteration were calculated on the basis of coexisting mineral chemistry and isotopic values. Hydrothermal metamorphism commenced at about 720?C and continued to about 550?C. Leucocratic veining took place at about 500?C. Alteration within brecciated horizons was also at about 500? to less than 400?C, and the trondhjemite was altered at about 550? to below 490?C. Pressures calculated from a diopside-bearing vein, based on a combination of fluid inclusion and isotopic analysis, were 90 to 100 MPa. This pressure places the sample, from Core 118-735B-70R in Unit V, at about 2 km below the seafloor.
    Language English
    Dates of publication 1991-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Conference proceedings ; Online
    Note This dataset is supplement to doi:10.2973/odp.proc.sr.118.121.1991
    DOI 10.1594/PANGAEA.757711
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  6. Book ; Online: (Table 1) Geochemistry of carbonate veins from basalts of the eastern flank of the Juan de Fuca Ridge, ODP Leg 168, supplementary data to: Coggon, Rosalind M; Teagle, Damon AH; Cooper, Matthew J; Vanko, David A (2004): Linking basement carbonate vein compositions to porewater geochemistry across the eastern flank of the Juan de Fuca Ridge, ODP Leg 168. Earth and Planetary Science Letters, 219(1-2), 111-128

    Coggon, Rosalind M / Cooper, Matthew J / Sud, Laboratoire de Geochimie des Roches Sedimentaires, Universite Paris / Teagle, Damon AH / Vanko, David A

    2004  

    Abstract: Leg 168 of the Ocean Drilling Program (ODP) investigated the heat flow, fluid chemistry and crustal alteration associated with ridge flank hydrothermal systems. Ten sites were drilled on the eastern flank of the Juan de Fuca Ridge, along an 80 km ... ...

    Abstract Leg 168 of the Ocean Drilling Program (ODP) investigated the heat flow, fluid chemistry and crustal alteration associated with ridge flank hydrothermal systems. Ten sites were drilled on the eastern flank of the Juan de Fuca Ridge, along an 80 km transect, between 20 and 100 km east of the spreading centre. Recovered cores consisted of 100-500 m of sediment with shallow penetration (1.7-48.1 m) into the underlying igneous basement (0.8-3.6Ma). Here we use the composition of calcium carbonate minerals, from veins within the upper basement, to reconstruct the evolving chemistry of hydrothermal fluids with increasing crustal age and sediment cover thickness. We show for the first time a clear link between the alteration of the basement rocks as recorded by secondary minerals, and the nearbasement sedimentary pore fluids, which are often assumed to be representative of the basement fluids responsible for low temperature alteration of the upper crust. Carbonates precipitated from basement fluids that ranged in strontium isotopic composition from near-modern seawater (87Sr/86Sr =~ 0.70918) to the near-basement pore fluid values at any one site. 87Sr/86Sr ratios are independent of mineralogy with both aragonite and calcite precipitating from variably evolved fluids with the range in carbonate 87Sr/86Sr increasing with crustal age. A parallel geochemical evolution of basement fluids and sediment porewaters is shown since 87Sr/86Sr ratios of near-basement pore fluids decrease from 0.709013 to 0.707108 away from the ridge axis. A correlation exists between 87Sr/86Sr ratios and d18O-calculated fluid temperatures, with more geochemically evolved carbonates having precipitated from warmer fluids. Basement fluid compositions, calculated from carbonate Sr, Mg, Fe and Mn concentrations combined with suitable partition coefficients, are also temperature-dependent. Given an observed increase in basement temperature with age, from 16?C to 64?C along the transect, a progressive chemical development of basement fluid is demonstrated. Carbonate veins in volcanic basement from ODP Holes 504B and 896A, on the Costa Rica Rift, record the same temperature compositional evolution of basement fluid as those from the Juan de Fuca Ridge flank. Although these locations have different thermal histories and therefore must have experienced different temporal geochemical evolution of basement fluid, basement temperature appears to be the dominant control on basement fluid composition.
    Language English
    Dates of publication 2004-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1016/S0012-821X(03)00697-6
    DOI 10.1594/PANGAEA.700965
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  7. Book ; Online: Rare-earth element concentration of anhydrite vein separated from ODP Site 1188 (Table 2), supplementary data to: Bach, Wolfgang; Roberts, Stephen; Vanko, David A; Binns, Raymond A; Yeats, Chris J; Craddock, Paul R; Humphris, Susan E (2003): Controls of fluid chemistry and complexation on rare earth element contents of anhydrite from the PACMANUS subseafloor hydrothermal system, Manus Basin, Papua New Guinea. Mineralium Deposita, 38(8), 916-935

    Bach, Wolfgang / Binns, Raymond A / Craddock, Paul R / Humphris, Susan E / Roberts, Stephen / Vanko, David A / Yeats, Chris J

    2003  

    Abstract: Ocean Drilling Program (ODP) leg 193 successfully drilled four deep holes (126 to 386 m) into basement underlying the active dacite-hosted Pacmanus hydrothermal field in the eastern Manus Basin. Anhydrite is abundant in the drill core material, filling ... ...

    Abstract Ocean Drilling Program (ODP) leg 193 successfully drilled four deep holes (126 to 386 m) into basement underlying the active dacite-hosted Pacmanus hydrothermal field in the eastern Manus Basin. Anhydrite is abundant in the drill core material, filling veins and vesicles, cementing breccias, and occasionally replacing igneous material. We report rare-earth element (REE) contents of anhydrite from a site of diffuse venting (Site 1188) which show extreme variability, in terms of both absolute concentrations (e.g., 0.08-28.3 ppm Nd) and pattern shape (LaN/SmN=0.08-3.78, SmN/YbN=0.48-23.1, Eu/Eu*=0.59-6.1). The range of REE patterns in anhydrite includes enrichments in the middle and heavy REEs and variable Eu anomalies. The patterns differ markedly from those of anhydrite recovered during ODP Leg 158 from the TAG hydrothermal system at the Mid-Atlantic Ridge which display uniform LREE-enriched patterns with positive Eu anomalies, very similar to TAG vent fluid patterns. As the system is active, the host-rock composition is uniform, and the anhydrite veins appear to relate to the same hydrothermal stage, we can rule out predominant host-rock and transport control. Instead, we propose that the variation in REE content reflects waxing and waning input of magmatic volatiles (HF, SO2) and variable complexation of REEs in the fluids. REE speciation calculations suggest that increased fluoride and possibly sulfate concentrations at Pacmanus may affect REE complexation in fluids, whereas at TAG only chloride and hydroxide complexes play a significant role. The majority of the anhydrites do not show positive Eu anomalies, suggesting that the fluids were more oxidizing than in typical mid-ocean ridge hydrothermal systems. We use other hydrothermal fluids from the Manus Basin (Vienna Woods and Desmos), which bracket the Pacmanus fluids in terms of acidity and ligand concentrations, to examine the dependence of REE complexation on fluid composition. Geochemical modeling reveals that under the prevailing conditions at Pacmanus (pH=3.5, T=250-300 ?C), Eu oxidation state and the relative importance of fluoride versus chloride complexing are very sensitive to small variations in oxygen fugacity, temperature, and pH. Patterns with extreme mid-REE enrichment may reflect speciation effects (free-ion abundance) coupled with crystal chemical control. We conclude that the great variability in REE concentrations and pattern shape is likely due to variable fluid composition and REE complexation in the fluids.
    Language English
    Dates of publication 2003-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1007/s00126-002-0325-0
    DOI 10.1594/PANGAEA.666862
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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