Seismic, gravity and magnetic studies, Broadlands geothermal field, New Zealand
1970; Elsevier BV; Volume: 2; Linguagem: Inglês
10.1016/0375-6505(70)90032-5
ISSN1879-3576
AutoresM. P. Hochstein, Trevor M. Hunt,
Tópico(s)Geological Studies and Exploration
ResumoInformation about structural features within the Broadlands field was sought using detailed seismic, gravity and magnetic surveys. Seismic measurements using the refraction method show the presence of several dome-shaped structures (rhyolite domes) but the greywacke basement could not be outlined. The gravity and magnetic surveys have been of little use in mapping structural features within the volcanic overburden. A residual gravity anomaly of up to +10 mgal covers most of the Broadlands field and is mainly caused by densification of the rocks within the field brought about by hydrothermal alteration of various rocks. This anomaly makes it difficult to determine the basement relief beneath the Broadlands field. Magnetic measurements give no information about the extent of the thermal area at depth. Volcanic rocks from inside the field were found to be non-magnetic.
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