| Title | The Occurrence, Distribution and Xrd Properties of Hydrothermal Clays at the Golden Cross Epithermal Au-Ag Deposit, New Zealand |
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| Authors | M.P. Simpson, J.L. Mauk and S.F. Simmons |
| Year | 1998 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | |
| Abstract | Hydrothermal clays display distinct zonation around veins in the Empire zone of the Golden Cross epithermal Au-Ag deposit. At shallow levels the main clays are interstratified illite-smectite and tentatively identified chlorite-conensite which grade downwards into illite and chlorite, respectively. Minor at depth corresponds to areas of low permeability. The overall zoning pattern of interstratified and illite presumably reflect a former deposit-scale increase in temperature with depth and towards veins; local variations in clay mineralogy, additionally reflect varying intensities of water-rock interaction. The interpretation of clay mineral transitions must be coupled with other geothermometric data to derive the possible interpretationof the thermal, chemical and hydrologic regimes of fossil geothermal systems. |