WADI VLF

[Klaud]

WADI VLF is a device mainly used to detected water (up to 100 meters). But I beleive that it can be used to find gold if the amount is not too small ...
WADI is detecting phase shift of frequencies used to communicate with submarines - 10 khz to 30 khz - . If the signal received is too faint, a transmitter device can be used around 1 Km.
WADI VLF is made by ABEM sweeden. Similar device are T-VLF from Iris-Instruments or EM16 from Geonics.

Has any one try to use such devices ?

http://www.abem.se/products/wadi/wadi.php
http://www.giscogeo.com/pages/emabwd.html
www.abem.se/products/wadi/vlf-freq.pdf

[99thpercentile]

VLF can be used to map faults, contacts, veins or geologic mapping. The target that you are looking for should be at least 50m long. I've never used VLF, this is just what we covered in my mining geophysics class. The instructor is one of the most famous mining geophysicists in the world so I believe him.

[Hemasri]

VLF for subsurface explorations

Yes, VLF, both Wadi and Geonics EM 16 is very good for subsurface explorations. I used many years for groundwater explorations in flat, dry zone of Sri Lanka. Fist I did VLF survey to find a suitable location to conduct deep electrical soundings. In many many cases both are coinsiding. Anyway, for groundwater explorations and mineral exploration (especially graphite and Sulphide) VLF can be used effectively. If anybody has technology to make a VLF phase shifting instrument, let me know. I have some knowledge in electronics, But I am not aware about, phase shifting circuits and attenuator circuit. In EM 16 they use two recievers for primary and secondary signals.

[Atul Asthana]

VLF for subsurface exploration

Could you please provide more details?
Do you have working principles of any of the devices?

[Hemasri]

Could you please refer, Patent articles in "geophysics" of this "geotech" section,

Will write you later.

Reg.

Could you please provide more details?
Do you have working principles of any of the devices?

[99thpercentile]

I would suggest getting copies of the following two books.

Reynolds, J.M., 1997. An Introduction to Applied and Environmental Geophysics, edn, Vol., pp. Pages, Wiley.

Telford, W.M., Geldart, L.P. & Sheriff, R.E., 2003. Applied Geophysics, edn, Vol., pp. Pages, Cambridge University Press.

You could also read the manufacturer webpages, see below.

http://www.geonics.com/html/vlfsystems.html


Read this short note as well

www-geo.phys.ualberta.ca/~unsworth/UA-classes/424/notes424/424C5.6-2006.pdf