Tracing Float

If a vein is exposed near the surface, but is covered with overburden, remnants of the vein called Float will frequently appear downhill in the overburden material. If the vein material is resistant to weathering, float usually starts appearing some distance downhill from the hidden vein outcrop.

If valuable minerals are found as float or chips, trenching is often necessary to expose the surface outcrop. If no minerals are found on the surface with trenching techniques, more sophisticated exploration methods using the sciences of geobotany, geochemistry, geology, and geophysics may be employed.
Trenching