What is QED mode 16 used for?
doug

The formation of gold deposits in South Africa
German-Canadian research team discovers new ore-forming process in ancient marine sedimentary basin
20 April 2017/Kiel. The Witwatersrand basin in South Africa hosts the largest known gold repository on Earth – but how was it formed? Scientists of the GEOMAR Helmholtz Centre of Ocean Research Kiel and Canadian research institutes were able to figure out how parts of the Earth’s largest gold deposits formed about three billion years ago. Crude oil and hot hydrothermal fluids played a major role. This study has been currently published in the journal “Precambrian Research“
  
doug

Just for the record my GPX5 operating with the GB set to fixed (which I prefer) over the same ground produces a response on the same hot rock type intrusions requiring a Re-GB. The QED appeared to require a once only manual GB figure adjustment.

As far as I am concerned my GPX5 does not operate a mono coil with the GB set to tracking as well as a GP3 in tracking, that I owned previously.

Gary.

The "Holy Grail" of ground balance is tolerance for an extreme range of soil types and the occasional pesky hotrock.

Look forward to the  results.
doug

The attached file is the lapsed WIPO patent by George Paltoglou.
Like many other GB patents it uses sample periods and a subtraction/null summation electronic circuit akin to an old fashioned balance beam as disclosed in a 1968 paper by Eric Foster.

After the TX signal, the ground minerals take time to decay as do any targets within the ground under the coil. Both the ground and target if present control the shape of that decay. If you take an old fashioned photo of that decay curve then using a pair of scissors to cut it vertically into slices it is possible to get the width of the slices correct so that when placed alternately on the sides of the balance beam they balance (are equal). There is however a fly in the ointment. The total width of the left hand samples must equal the total width of the right hand side samples to null the signal from the Earth Field and Magnetic soil simultaneously.


Currently the QED uses 2 short TX and 1 long TX to differentiate. The Paltoglou patent mentions using 3 different widths. When time allows I will try it out and if successsful at handling highly variable ground/hot rocks, add it to the QED "MODES"

Was out just recently using the QED with Commander 11" mono over some ground that had previously been cleared to expose a surface layer of whitish type clay with orange colour rocky type intrusions exposed in various places at the surface and slightly beneath the surface once the surface was scraped away with the pick.

The ground balance figure for the clay was not all that high at 107 however once I encountered a orange rocky type intrusion it produced a rising response to the QED. I manually pressed the down arrow button to lower the GB figure from 107 down to 103 and the response from the intrusion disappeared. Once I passed by the intrusion and back onto the clay I manually raised the GB figure back up to 107 until another intrusion was encountered.

After I detected another rising response intrusion it occurred to me why not leave the detector set at 103 that allowed me to cancel out any intrusions and see if I can continue to detect without a response from the clay even though the clay produced a higher GB figure.

Well the detector appeared to have no further issues from this particular type ground.

The QED settings were THS-B: 48, THS-A: 60, GAIN: 1 & MODE: 6.

Gary.
  

Epithermal Gold Deposits
Epithermal gold deposits are among the  richest gold deposits in the world with some bonanza grade ore shoots containing more than 1000 g/t gold, or in other words, a kilogram of gold for every tonne of rock mined. Unfortunately, the tonnage of ore in epithermal veins is typically small compared with other types of lower grade gold deposits.
  
link-https://www.geologyforinvestors.com/epithermal-gold-deposits/
doug

Diversity of Gold Deposits, Geodynamics and Conditions of Formation: A Perspective View
ABSTRACT
Gold occurs in a wide range of deposit types and settings. In the last decade, significant progress has been made in the definition, classification, characterization, thereby aiding understanding of the main gold deposit types. The present work aims to provide an update on the current state of knowledge on the different types of gold deposits models, geodynamics, their mode of formation and the condition suitable for their formation Several subsets of gold deposits are distinguished from one another on the bases of and their main geological models and their mode of formation described. Gold deposits of magmatic-hydrothermal origin are classified into Porphyry, Epithermal, Skarn, Iron Oxide-Copper-Gold and Intrusion related deposits; those of hydrothermal origin are Orogenic, Volcanogenic Massive Sulphide deposits, and Carlin-type; while those of Sedimentary Origin are placers. In terms of the major Period of gold deposit formation, the Mesoarchean was the largest gold period. Other gold peaks followed, particularly in the Neoarchean, Paleoproterozoic and Paleozoic while numerous and diverse gold deposit types were formed during the Cenozoic era.Wide varieties of geodynamic contexts in which each of the gold deposits are formed being explained while the conditions favourable for its formation are also being summarized. With the recent rise in the price of gold, mining companies and research centers continue to provide lighting of the key geology features of then ore-forming environments and the key geologic manifestations of the different deposit types.
Link only available to registered forum members
  
doug

Link only available to registered forum members.
  
doug