Boron in Soil Over Naike and Whitford Low-Enthalpy Geothermal Fields, New Zealand

Abstract

Mercury, arsenic, bismuth, antimony and boron soil surveys were conducted over two low-enthalpy, sedimentary-hosted, geothexmal fields, Naike and Whitford, in New Zealand. Analysis was by ICPAES following a leach. Appreciable amounts of boron (0.13 to 4.25 were found at both Whitford and Naike; As, Hg, Bi and Sb were not detected. A positive strong boron anomaly exists in the warm spring area of Naike. This was probably created by boron transported in water phase, a conclusion supported by the relatively high concentration of Na Mg and Li in soils of the same area. Weaker anomalies (1.1 to 2 were found at Naike and Whitford. These are problems caused by boron transported in the vapour phase and indicated more permeable areas and possible upflow zones. Boron in soils can be used as a pathfinder for enthalpy geothermalsystem and as a guide to upflow areas.