| Abstract |
The objective of paleohydrological reconstruction is to develop a model in time and space of the hydrothermal system responsible for alteration, and then to use this to understand the extent to which alteration reflects current conditions in the hydrothermal, and therefore whether it can be used for prediction. In particular, it is used to determine whether geophysical method such as resistivity are responding to current or relict alteration, and hence whether they are able to be reliably used to determine the extent of the current system. The same methods are used in fossil hydrothermal systems to understand epithermal mineral deposits. The principles and techniques are the same. To do this, it is necessary to determine the directions of fluid flow, and the physico-chemical conditions in the hydrothermal system, based on secondary mineralogy, in as much detail as possible, then compare the results with the actual measured temperatures and hydrology. Any discrepancies indicate erosion or other tectonic or hydrothermal disturbances. |