gold undercover zone, page-7

Hi gonesolow,

Generally the shallow cover sediments are of little interest unless they contain mineral sand, alluvial gold etc. What interests geologists is more likely the structures in the rocks underneath. The Victorian studies have been focussed on these buried structures. One example: Gold is often associated with large scale, linear zones of weakness called shear zones. Both Hill End and Bendigo gold deposits have this association. Shear zones are clusters of fractures that may extend many kilometres into the Earth. One effect is to lower the density of rocks within the shear zone and in turn, this lowers the force of gravity by a tiny amount. Sensitive instruments can measure these gravitational changes and they can be mapped. The zones have no respect for the channel of the Murray River so the linear features on Victorian maps can be extrapolated into NSW.

It just happens that there is a North South trend for many of these basement structures. We can reasonably expect most of them to continue into NSW.