Hydrothermal eruptions in the Waiotapu geothermal system, New Zealand; their origin, associated breccias, and relation to precious metal mineralization

Hedenquist, Jeffrey W.; Henley, Richard W.

doi:10.2113/gsecongeo.80.6.1640

Cited by 300 publications

(118 citation statements)

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“…The apparent salinity of fluid inclusions (Hedenquist and Henley 1985) was calculated from Tm ice using the equation of Bodnar and Vytik (1994) and expressed in wt% NaCl eq. To assess the presence of non-condensable gases in the inclusions, a number of crushing tests was carried out (cf.…”

Section: Methodsmentioning

confidence: 99%

“…might provide further information on the chemical composition of the parent fluid. However, the possible presence of dissolved CO 2 in fluid inclusions should be considered, as this may depress the Tm ice and thus result in an overestimation of the real salinity (Hedenquist and Henley 1985). In L1 inclusions, the range of CO 2 varies between 0 mol% (inclusions displaying Tm ice of 0.0 °C), suggesting that they represent almost pure water, and 0.14 mol%, as indicated by the crushing tests.…”

Section: Calcite Vein Depositionmentioning

confidence: 99%

“…Accordingly, thermal springs occurring in southern Tuscany and in other geothermal fields elsewhere mainly relate to extensional structures (Kerrich 1986;Hancock et al 1999;Brogi and Capezzuoli 2009), enhancing the genetic link between travertine deposition and recent tectonics. The local occurrence of wall rock fragments in the banded calcite veins suggests that travertine deposition was accompanied by the injection of overpressured fluids, probably associated with a hydrothermal eruption (cf., Hedenquist and Henley 1985) and hydrofracturing (Gudmundsson et al 2002;Uysal et al 2009;Buttinelli et al 2011). Recent episodes of fossil and present-day hydrofracturing are documented in the nearby Larderello geothermal area, in the form of phreatic craters and explosions (Marinelli 1969), driven by high-pressure fluids (Ruggieri and Gianelli 1999;Gianelli 2008).…”

Section: Calcite Vein Depositionmentioning

confidence: 99%

See 2 more Smart Citations

Investigating fossil hydrothermal systems by means of fluid inclusions and stable isotopes in banded travertine: an example from Castelnuovo dell’Abate (southern Tuscany, Italy)

Rimondi

Costagliola

Ruggieri

et al. 2015

Int J Earth Sci (Geol Rundsch)

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Section: Methodsmentioning

confidence: 99%

Section: Calcite Vein Depositionmentioning

confidence: 99%

Section: Calcite Vein Depositionmentioning

confidence: 99%

See 1 more Smart Citation

Investigating fossil hydrothermal systems by means of fluid inclusions and stable isotopes in banded travertine: an example from Castelnuovo dell’Abate (southern Tuscany, Italy)

Rimondi

Costagliola

Ruggieri

et al. 2015

Int J Earth Sci (Geol Rundsch)

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“…Within this area, the Waiotapu region is characterized by a large number of springs exhibiting elevated arsenic concentrations (Mountain et al 2003). With its 65-meter diameter, the Champagne Pool (CP) represents the largest geothermal feature of Waiotapu with arsenic concentrations ranging from 2.9 to 4.2 mg/L (Hedenquist and Henley 1985). The inner rim of CP is characterized by subaqueous orange amorphous As-S precipitate responsible of the characteristic orange color (Jones et al 2001).…”

Section: Taupo Volcanic Zone New Zealandmentioning

confidence: 99%

Metagenomics of microbial and viral life in terrestrial geothermal environments

Strazzulli

Fusco

Cobucci‐Ponzano

et al. 2017

Rev Environ Sci Biotechnol

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Geothermally heated regions of Earth, such as terrestrial volcanic areas (fumaroles, hot springs, and geysers) and deep-sea hydrothermal vents, represent a variety of different environments populated by extremophilic archaeal and bacterial microorganisms. Since most of these microbes thriving in such harsh biotopes, they are often recalcitrant to cultivation; therefore, ecological, physiological and phylogenetic studies of these microbial populations have been hampered for a long time. More recently, culture-independent methodologies coupled with the fast development of next generation sequencing technologies as well as with the continuous advances in computational biology, have allowed the production of large amounts of metagenomic data. Specifically, these approaches have assessed the phylogenetic composition and functional potential of microbial consortia thriving within these habitats, shedding light on how extreme physico-chemical conditions and biological interactions have shaped such microbial communities. Metagenomics allowed to better understand that the exposure to an extreme range of selective pressures in such severe environments, accounts for genomic flexibility and metabolic versatility of microbial and viral communities, and makes extreme-and hyper-thermophiles suitable for bioprospecting purposes, representing an interesting source for novel thermostable proteins that can be potentially used in several industrial processes.Keywords Hyperthermophiles Á Geothermal environments Á Microbial and viral metagenomics Á CRISPR Á Enzyme discovery BackgroundHot springs populated by extreme thermophiles (T opt : 65-79°C) and hyperthermophiles (T opt [ 80°C) (DeCastro et al. 2016) are very diverse and some of them show combinations of extreme chemo-physical conditions, such as temperature, acidic or alkaline pHs, high pressure, and high concentrations of salts and heavy metals (López-López et al. 2013). As with all studies of environmental microbiology, our understanding of the composition, functional and physiological dynamics, and evolution of extreme-and hyper-thermophilic microbial consortia has lagged A. Strazzulli Á M. Moracci Á P. Contursi

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“…Jigsaw-puzzle textures, however, are common in rocks drilled in geothermal fields and in hydrothermal ore deposits, where they have been interpreted to have formed by hydrofracturing (e.g., Phillips, 1972;Hedenquist and Henley", 1985;Sibson, 1987;Gianelli and Bertini, 1993). Jigsaw-puzzle breccias filled with hydrothermal minerals are also common along small- offset oceanic faults in the basal sheeted dike complex of the Josephine ophiolite (Alexander et al, 1993).…”

Section: Jigsaw-puzzle Breccias and Vein Networkmentioning

confidence: 99%

Structural Evolution of Upper Layer 2, Hole 896A

Harper¹,

Tartarotti²

1996

Proceedings of the Ocean Drilling Program, 148 Scientific Results

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An analysis of the state of stress in the upper ocean crust shows that high hydrostatic pore-fluid pressures will result from the thick overlying water column, providing that the upper crust is sufficiently permeable. High pore-fluid pore pressures will result in very low effective stresses in the upper ocean crust. Such conditions favor deformation by formation of extension fractures and mixed mode (combined extension and shear) fractures rather than by frictional sliding on faults. High pore-fluid pressures are considered very likely to have produced many of the structures in Hole 896A, including jigsaw-puzzle breccias and associated vein networks, cement-supported breccias, and fibrous veins. These structures record an overall volume increase, and their geometry and offset markers indicate formation as extensional fractures or, in some cases, mixed mode fracturing. The geometry and textures of jigsaw-puzzle breccias and associated vein networks suggest formation by longitudinal (axial) splitting, a type of brittle rock failure that occurs in rock deformation experiments done under stress conditions similar to those in the upper ocean crust (σ 2 ' and σ 3 ' < 0). Breccias can form by disaggregation during volume increase associated with extension or mixed mode fractures. The textures of many breccias formed in this way are very similar to those of sedimentary breccias and thus the sedimentary vs. tectonic origin of many breccias in the drill core is uncertain, especially because the margins of the breccias are not usually preserved in core. The fibrous veins generally postdate jigsaw-puzzle breccias and vein networks. They probably formed by repeated cycles of hydrofracturing and sealing of fractures (crack-seal mechanism). The extension directions indicated by both fibrous and nonfibrous veins are highly variable in orientation, even within a single piece, and vein networks suggest simultaneous extension in several directions. In addition, small faults having fibrous slickensides occurring below 334 m below seafloor indicate normal, reverse, and oblique slip. The style of brittle deformation observed in Hole 896A should produce microseismicity characterized by a nonuniform stress field and non-double-couple earthquakes. Such microseismicity characterized geothermal activity in the post-rifting stage at Krafla, Iceland.

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Hydrothermal eruptions in the Waiotapu geothermal system, New Zealand; their origin, associated breccias, and relation to precious metal mineralization

Cited by 300 publications

References 0 publications

Investigating fossil hydrothermal systems by means of fluid inclusions and stable isotopes in banded travertine: an example from Castelnuovo dell’Abate (southern Tuscany, Italy)

Investigating fossil hydrothermal systems by means of fluid inclusions and stable isotopes in banded travertine: an example from Castelnuovo dell’Abate (southern Tuscany, Italy)

Metagenomics of microbial and viral life in terrestrial geothermal environments

Structural Evolution of Upper Layer 2, Hole 896A

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