Practical Observations of Epithermals
(mostly low sulphidation)
Based on Site Visits and geology/mining knowledge of Keith Goode:(most of the experience and knowledge came during site visits {typically 1 week with a company} under~25yrs Eagle Research Advisory / ERA; – ie mostly Australasia, Thailand, Sth America, & Turkey)
Low Sulphidation Epithermals – typical properties:
- Gold and silver mineralisation, can get native silver
- Colloform, banding, sometimes get black ginguro
- Vertical or almost vertical typically quartz veins
- Often strike NW/SE or NE/SW (observation)
- Base of a boiling zone, mineralisation to surface
- Can have barren quartz veins on surface
- Can get parallel veins up to ~2.5 – 5km apart (observation)
- Breccias, No 1 target brecciated colloform
- If base metals, high sulphidation & probably refractory (note if As is crystalline, should be non-refractory)
- Patterns – NWSE, Lambdas
- Parallel – possibly 2.5 to 5km apart & sinters
- Rolling/offset
- - Cerro Vanguardia determined by endowment
- - drilled after 1200 diamond holes
- - can get gaps and offset
- - also seen Cerro Moro and Cracow
- Terry Leach Table
- Ground Conditions