...Francesco Civilini; Aasha Pancha; Martha Kane Savage; Steven Sewell; John Townend Abstract We have determined subsurface structure using the refraction microtremor (ReMi) method at the Ngatamariki geothermal field, Central North Island, New Zealand. The local geology is such that refraction...

...Patrick R. L. Browne; Sue F. Courtney; C. Peter Wood Abstract Chips ejected during the initial openings of Ngatamariki well, NM2, in the Taupo Volcanic Zone, New Zealand, consist of euhedral crystals of wairakite, prehnite, and Fe-rich epidote, plus rare quartz and pyrite. The shapes of some...

...B.W. Mountain; L.G. Benning; J.A. Boerema Abstract To study the rate of growth of sinters in New Zealand hot springs, field experiments were conducted in seven geothermal areas. At Wairakei, fan-shaped subaqueous deposits of amorphous silica grow rapidly (350 kg a –1 m –2 of drain wall...

...Fig. 2. Geologic map of the Ngatamariki geothermal field, showing surface lithologies and the locations of deep wells, hot springs, fault traces, field resistivity boundary, and cross section trace of Figure 3 . Coordinates in NZ Map Grid NZMG. The surface geological units are from Leonard et...

... collected into the plastic bottle. Table 3 Trace Metal Analyses of Chloride Water Samples from Geothermal Wells Field Broadlands-Ohaaki Kawerau Mokai Ngatamariki Well Br47 Br47 Br47 Ka25 Ka25 Mk6 Mk6 Mk6 Mk6 Mk6 Nm4 Nm4 Nm4 Nm4 Date 10/1/2002 10/1/2002...

...Figure 8. Cross sections of the modern distribution of Paeroa Subgroup ignimbrites (see Fig. 7A ): (A) northwest-southeast, through the Te Weta and southern Paeroa fault blocks at the Te Kopia geothermal field, (B) from the Orakei Korako to Ngatamariki geothermal fields, and (C) west-east...

... their predominantly meteoric origin ( Giggenbach, 1995 ). The compositions from shallow wells at Ladolam, Lihir Island, Papua New Guinea, occupy the field labelled “Ladolam trend,” representing a mixing trend between local meteoric water and deep magmatic water ( Carman, 2003 ); the star represents the isotopic...

...Fig. 2. A. Geothermal sample clumped isotope results compared to temperature constraints from T h and well fluid discharge measurements. Samples are sourced from three geothermal fields: Wairakei (WK-80), Broadlands-Ohaaki (BR-6, 13, 15, 21, 27, 42), and Ngatamariki (breccia). Discharge...

... understanding and enhancing geothermal systems without the cost of traditional seismic acquisition. Civilini et al. present a pilot study of the refraction microtremor method at the Ngatamariki geothermal field (central North Island, New Zealand), where refraction and reflection studies are hindered...

...–4C ) ( Leonard et al., 2010 ). Silicic plutonic bodies have been proposed as being widely present ( Evison et al., 1976 ; Stern, 1985 ); however, the only in-situ plutonic bodies identified are in the Ngatamariki geothermal field at 2.6 km or greater depth ( Fig. 4B ) ( Browne et al., 1992...

...Fig. 13. Field photographs showing tree branches in spring pools. (A, B) Examples of tree branches in Iodine Pool, Waimangu (water temperature T = 88 °C, pH 8.9) and Hoani, Tokaanu ( T = 62.6 °C, pH 7.0), coated with opal-A precipitates. Wood inside branches has not been replaced. Branches up...

... samples investigated. In the vein host rock, the dominant matrix and void spaces were intensely silicified by secondary quartz and primary feldspar was replaced by patchy adularia pseudomorphs (Fig. DR2D). Geothermal fields are geographically stable features that exhibit thermal variability...