detecting techniques
– continued
page 38
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page 38
GP 3500
Covering the search area
•
As the user moves forward slowly, the search pattern should resemble a snaking path.
•
To ensure that productive ground is thoroughly searched, approach the area from
3 different directions.
Overlap each sweep
•
Each sweep of the coil should overlap the area covered by the previous sweep to ensure
a full coverage of the area being searched.
•
Be aware of the search pattern of the coil being used and overlap sweeps to take this
pattern into account. If using a Monoloop coil a tighter overlap is required to ensure that
targets at maximum depth are not overlooked.
•
See also Pinpointing Technique,
page 41.
Figure 5.2
Search path
Figure 5.3
Search area from
3 directions
prospecting techniques
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5 detecting
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page 39
GP 3500
GP 3500
www.minelab.com
page 39
The GP 3500 has superior ground balancing and it is possible to find quite large
objects near the surface in well-worked areas where other detectors have been unable
to cope with the high degree of mineralization and/or salt. Therefore the user should
dig all target signals, even in previously detected areas.
•
Very sudden or large changes in the mineralization of an area may produce a signal
from the detector. Usually this signal is very broad, and often only present in one
direction.
•
In some goldfields, a response may be received from a concentration of orange/reddish
dyke material or clay. Remember, a metal target will get louder by getting the coil even
centimeters closer.
•
If detecting areas of extremely variable mineralization, detecting with the contours rather
than across the changes will often stabilize the effect.
•
In some ground (particularly heavily mineralized areas) the operator may need to sweep
the coil 1 or 2 cm above the ground. This should give a more stable threshold and less
ground noise.
•
With faint or indistinct signals that you are not sure of scrape a few centimetres off the
surface with your pick and see if the signal becomes clearer.
Big GOLD.
Many detector operators have no trouble finding their share of small gold, but often are
disappointed at the lack of larger gold found at depth, even though they have dug up to
1m for a soft drink can or a horse shoe. The reason is that big gold gives a much
different response to the smaller shallower pieces. The signal is often quite broad, and
there is very little pitch variance. Just something to be aware of.
For Maximum Gold Recovery
•
Keep the coil as close to the ground as possible.
•
Listen very carefully - this is more important than looking.
•
SLOW DOWN! Do not rush, take your time.
•
Have a positive mind set, and imagine a nugget at every next sweep!!
•
Remember that covering a small section of ground thouroughly will be
more productive than randomly searching a larger area.
