 | | Journal (article/letter/editorial) | | GEOLOGISTS 1987 NO. 5 The RotokawaGeothermalSystem,New Zealand:An Active Epithermal Gold-DepositingEnvironment...Scientificand Industrial Research,PrivateBag,Petone,New Zealand Abstract The Rotokawageothermalsystemis lessthan...underlyingMesoziocgraywackebasementin the Taupo volcaniczone, a region dominatedby extensionaltectonics.At...060 yrs ago and is presently occupiedby an acid lake (LakeRotokawa)with a pH • 2. Significantbeddedsulfurdeposits...Significantbeddedsulfurdeposits which formed in an earlier crater lake existbeneaththe presentlake. The deep fluidsare |  | | Journal (article/letter/editorial) | | 95-108 Gold-SilverOre-GradePrecipitates from New Zealand Thermal Waters B. G. WEISSBERG Abstract Gold-silverore...areas along the easternmargin of the Taupo Volcanic Zone, New Zealand. They occur as red-orange amorphoussulfideswith...106 kg/hr, Wairakei system,1951) combinedwith long lifetimes (e.g., 5 X .105yr, Wairakei) are adequateto...hydrothermalalterationprod- and Whakarewarewa,New Zealand (2 ppm Au and uctsfoundin manyepithermal ore...area is exceptionalin and the Hauraki Peninsula,New Zealand) are similar havingas muchas 6% Ag in the scaleoccurringas |  | | Report (issue) | | NEW ZEALAND DEPARTMENT OF SCIENTIFIC AND INDUSTRIAL RESEARCH NEW ZEALAND GEOLOGICAL SURVEY 125th ANNIVERSARY...1865 -1990 NEW ZEALAND GEOLOGICAL SURVEY BULLETIN 104 ISSN 0077-9628 Minerals of New Zealand by G. L....initials should be G.T., not G.L. Lower Hutt, New Zealand 1990 I I Beach sand, alluvium, • terrace...Figure 1. Simplified geological sketch-map of New Zealand. 0 20 40 60 80 100 KM l INTRODUCTION It...Morgan's "Minerals and Mineral Substances of New Zealand" was published, as NZ. Geological Survey bulletin |  | | Journal (article/letter/editorial) | | DSIR Chemistry Division, Private Bag, Petone, New Zealand (Received February 22, 1989; accepted in revisedform...predominant dissolved As species are H3As0! and HzAs3S;. Orpiment solubility is limited by the reactions: 0.5As2S3...pK90 = -3.42 + .06 A formational free energy for orpiment has been calculated as AC”, = -96.72 kJ/mol. Measured...concentrations of As in hot springs of the Taupo Volcanic Zone, New Zealand, are consistent with those predicted...AsOt. When H,AsO’: is the dominant As species, orpiment deposition is likely to occur in response to fluid |  | | Journal (article/letter/editorial) | | particularly IS epithermal orebodies in any particular district, irrespective of whether or not paleosurface features...neutral-pH, alkali chloride waters along streams and on lake margins and bottoms, although shallow boiling also...level of Frying Pan Lake (6-m deep, pH 3.5, 55 °C), Waimangu geothermal system, Taupo Volcanic Zone, North...North Island, New Zealand (see Simmons et al. 1993) The reactive H2S-bearing steam condensate formed in...the Ladolam LS gold deposit, Lihir Island, Papua New Guinea, are represented at surface by steaming ground |  | | Journal (article/letter/editorial) | | and Industrial Research, Private Bag, Petone, New Zealand (Received June 9, 1988; accepted in revised...by pyrite, pyrrhotite, sphalerite, galena. In New Zealand a number of active geothermal systems are precipitating...than 0.1 ttg k8 -t, WEISSaERG (1969). The active Rotokawa geothermal system has deposited approximately...formation of geochemical anomalies in stream and lake sediments and soils (JENNY, 1968; HEM, 1976; HOHL...especially in the active hydrothermal systems in New Zealand. One of the primary observations from this study |  | | Book (edition) | | have incorporated into Chapter 1. Apart from the new material discussed above I have included a description...and epithermal gold mineralization and introduced new material into most chapters of this book. This work...places as far apart as France, California, Japan, New Zealand and Spain and the offers to translate it into...Some chapters have been considerably expanded and new sections added; in particular on disseminated gold...perennial complaint of industrial employers, that the new graduate has little or no commercial awareness, such |
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