| Title | Geophysical Survey of the Pico Alto Geothermal Prospect, Terceira Island, Azores |
|---|---|
| Authors | Anderson, E., Ussher, G., Tearney, K. |
| Year | 1982 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | |
| Abstract | A geophysical study has been made of the to Geothermal Prospect located within the caldera of Guil herme Moniz Volcano on the island of Terceira. Gravity surveys have ined major structural trends and located the outer boundary of the Caldera. The Furnas do Enxofre hydrothermal area 1ies with in the complexly faulted western Caldera margin. The Caldera has a surface area of 25 and is infilled to depth of below sea level. Resistivity traverses and soundings indicate hydrothermal teration of caldera in fill to a mean level of rising to 450m at Furnas do Enxofre. Present geothermal fluid levels are Snferred to be at about sea level. Probable outflows are recognised to the north and north-east. A regional Self-potential high over the area is indicative of a deep geothermal system. Caldera faults which correllate with short wavelength SP highs are inferred to be preferred conduits for ascending geothermal fluids. Magneto-tel luric results indicate low resistivities associated with hot, essentially dry, hydrothermal l y tered rocks at 3 to below the Caldera. |