Field-Based Tests of Geochemical Modeling Codes: New Zealand Hydrothermal Systems

ABSTRACTHydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will determine how the codes can be used to predict the chemical and mineralogical response of the environment to nuclear waste emplacement. Field-based exercises allow us to test the models on time scales unattainable in the laboratory.Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei and Kawerau geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions.

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Silica accumulation rates for siliceous sinter at Orakei Korako geothermal field, Taupo Volcanic Zone, New Zealand

Geothermics ◽

10.1016/j.geothermics.2018.11.007 ◽

2019 ◽

Vol 78 ◽

pp. 50-61 ◽

Cited By ~ 5

Author(s):

Bridget Y. Lynne ◽

Alan Boudreau ◽

Isaac J. Smith ◽

Gary J. Smith

Keyword(s):

New Zealand ◽

Geothermal Field ◽

Taupo Volcanic Zone ◽

Accumulation Rates ◽

Volcanic Zone ◽

Siliceous Sinter

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Matrix permeability of reservoir rocks, Ngatamariki geothermal field, Taupo Volcanic Zone, New Zealand

Geothermal Energy ◽

10.1186/s40517-017-0088-6 ◽

2018 ◽

Vol 6 (1) ◽

Cited By ~ 9

Author(s):

J. L. Cant ◽

P. A. Siratovich ◽

J. W. Cole ◽

M. C. Villeneuve ◽

B. M. Kennedy

Keyword(s):

New Zealand ◽

Geothermal Field ◽

Taupo Volcanic Zone ◽

Volcanic Zone ◽

Reservoir Rocks ◽

Matrix Permeability

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A microearthquake survey at the Ngawha geothermal field, New Zealand

Geophysics ◽

10.1190/1.1441153 ◽

1981 ◽

Vol 46 (10) ◽

pp. 1467-1468 ◽

Cited By ~ 2

Author(s):

Russell Robinson

Keyword(s):

New Zealand ◽

Hot Springs ◽

Geothermal Field ◽

Hot Water ◽

Taupo Volcanic Zone ◽

Thermal Activity ◽

Volcanic Zone ◽

Depth Level ◽

Geothermal Exploration ◽

The North

A twenty day microearthquake survey of the Ngawha geothermal field, New Zealand, was undertaken in order to establish the level of preproduction seismicity and to test the usefulness of such surveys in geothermal exploration. The Ngawha geothermal field, in the far northwest of the North Island (Northland) is associated with a region of Quaternary basaltic volcanism. It is not a part of the much more extensive Taupo volcanic zone in the central North Island, site of the well‐known Wairakei geothermal field, among others. Although surface thermal activity at Ngawha is limited to a few relatively small hot springs, resistivity surveys have outlined a [Formula: see text] area of hot water at the 1-km depth level (Macdonald et al. , 1977). Test bores to that depth have encountered temperatures of up to 250 °C within Mesozoic graywacke. Overlying the graywacke is about 500 m of Cenozoic claystone and siltstone which forms an impermeable cap.

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