CARMELA BURNS on JULY 19, 2012

“The recent rush to find graphite and vanadium deposits to satisfy potential demand in green energy applications is reigniting airborne electromagnetic (EM) methods as highly effective exploration tools.”

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The well-known Schumann Resonance phenomena of the ionosphere produce clearly discernable electromagnetic waves. The Schumann Resonance frequencies of interest are 7.8, 14.3, 20.8, 27.3 and 33.8±1.0 Hz with a spectral band width of approximately 20%. Their peak strength usually is at around 10, 16 and 22 hours GMT. The measurements are energized by the electromagnetic energy of the Schumann resonances as well as the energy of the so-called 1/f noise of electromagnetic waves with frequencies around one Hertz and below. The observable strength of these electromagnetic waves will include variations because of leakage into the earth at a rate that will vary as a function of local geophysical properties. They can be received on, in or above the surface of the earth or in the sea waters. These modified electric (E-type) and magnetic (B-type) emissions (the signal we are interested in) are very small when compared to the other electromagnetic signals (which are considered to be noise). This invention is used to locate geophysical anomalies by determining where electromagnetic waves are potentially modified by geophysical anomalies.

It includes a moving platform equipped with a recording unit for recording the position of the platform. The system also comprises three first measuring units or sensors, adapted to record a varying electric field strength and a varying magnetic field strength at chosen intervals and thus positions, said first measuring units being adapted to measure said field strengths in three independent and mutually orthogonal directions at frequencies in a chosen range. The system includes a calculation unit for combining the measurements from each of said first sensors and calculating and recording as well as comparing the field strength vectors of the varying measured fields at each position, to find anomalies.

The purpose of the invention is to recognize the presence of anomalous volumes of material, their nature, depth, geographical location and extent below the surface of the earth by passively detecting relative differences in the natural electric (E-type) and magnetic (B-type) emissions in three dimensions; more specifically the field strengths are measured by a 3D sensor system that moves in a survey area of interest on or over land or above, on, or under water. This is achieved through recognizing relative differences in signal characteristics of continuous measurements in a survey grid. More specifically the objects stated above are obtained by a system and method characterized as stated in the accompanying independent claims.

US Patent Application 20110066379 – SURVEY SYSTEM FOR LOCATING GEOPHYSICAL ANOMALIES

Medusa Explorations from Netherlands is developing sensors for gammaray surveys. They are proud to see how their radiation sensors are used around the world for mapping soil properties in every detail needed.

“It is not only our technical skills that create good sensor systems. Our own surveyors are our most demanding clients, focussing development to robustness and useability of our sensors

and software.”

Measuring gamma radiation is not simple. Or rather, it is; the problems arise in the interpretation of the data, which will be influenced considerably by the type of detector used, the shape of the hole drilled and any number of other variable factors affecting the measurements. Medusa has developed a system where every gamma tool can be calibrated. The software results in flawless analyses of the measured results. This is one way not to be tripped up by the measuring equipment. Indeed, the software is the very essence of user friendliness: one button is all you need. Medusa’s software is also suitable to re-analyse old data.

UBC-GIF has finished 3D modeling of resistivity gradient survey data with EH3Dinv code (http://era-max.ca/examples.html, last two examples ). EH3Dinv is a computing code developed at UBC − GIF for inverting controlled source frequency-domain EM data to recover a 3D electrical conductivity (Inversion of 3D electromagnetic data in frequency and time domain using an inexact all-at-once approach. Eldad Haber, Uri M. Ascher, and Douglas W. Oldenburg. GEOPHYSICS, VOL. 69, NO. 5, 2004; P. 1216–1228).

The ERA’s technology, in brief, is “cross-disciplinary” – between frequency-domain and direct current (DC) concepts. The technology provides high resistivity resolution by grounded, non-contact and/or combined modes of electrical field measurements at 1.22-2500Hz. In comparison with DC method ERA equipment is several times more sensitive and in comparison with frequency-domain is defined as high-resolution.

ERA ZOND-MULTIMAX includes comprehensive tools for protocol generating and executing of automated geoelectric imaging (tomography) procedure;

- processing and analysis of the tomography data;

- usability and full compatibility with ERA equipment;

- creating and controlling any measurement protocol including for ground and water area 2D/3D tomography, cross-borehole imaging;

- auto optimization of arrays and protocols most suitable for geolectrical and ground conditions.

The SSW Probe developed by Instrumentation GDD Inc. It reduces dilution and increases ore grade within mining operation.

Several mines use the GDD SSW probe to log nickel, copper and iron sulphides in blast holes. By lowering the probe in the blast hole, a profile of the electromagnetic (EM) response is measured and obtained in real time making it useful for finding out ores content. Indeed, logged drill holes in nickel mines have demonstrated that ores content of nickel, cobalt, copper, and PGM are often proportional to the intensity of the probe EM response. Quick and inexpensive, probing a 30 m depth blast hole within 10 cm intervals will take less than 2 minutes.

Surveying a drill hole with a GDD SSW probe helps to determine the shape of the high-grade ore body within the waste rock and low grade ore. Using this tool, user will know exactly where to stop blasting thus saving time and money. The SSW probe can also be used to discover and mine pockets of rich ore that are otherwise left in place. Increase ore grade at the mill and get rid of the waste!

More than one month ago ION and BGP took another bold and pioneering step on behalf of the seismic industry for, on that day, they launched INOVA. Legally known as INOVA Geophysical Equipment Limited, this new and independent company is owned 51% by BGP and 49% by ION Geophysical Corporation. Combining the acknowledged strengths of its parents, INOVA aspires to engineer and deliver innovative land seismic technologies that can stand up to the rigors of acquisition in any operating environment. INOVA’s comprehensive portfolio of offerings  includes path-breaking products such as Aries II, FireFly, VectorSeis, and the AHV-IV Commander vibroseis vehicle.

Ivan Hrvoic, President of GEM, explains REQUIREMENTS FOR OBTAINING HIGH ACCURACY WIТН PROTON MAGNEТOMERS.

The 2009 Exploration Program at the MAN, Alaska project included a new ZTEM airborne survey (Z axis Tipper Electromagnetic system), extensive geological mapping and a proprietary fluxgate time domain ground EM surveys (full waveform streaming multi sensor fluxgate array).  The 2009 geophysical programs (ground fluxgate TEM, ZTEM, and BHEM) were considered a great success.  These very compelling geophysical targets, are the best discovered to date on the MAN property and the foundation for a productive 2010 exploration program.

3D inversions of aeromagnetic data, as well as several widely spaced deep drill holes show a consistent presence of abnormally thick ultramafic bodies with localized deep feeders. Last year’s results add to the evidence that the MAN property is the main intrusive centre for Triassic magmatism that generate the extensive nickel, copper and PGE (platinum group elements) bearing ultramafic intrusions and coeval lavas within the Alaska, Yukon and BC, segments of the Wrangelia terrain.  Drill results to date come from the holes targeted using the proprietary ground time domain EM survey (TEM), in conjunction with the new ZTEM airborne survey and previous ground gravity and VTEM airborne surveys.

Interpretation of the 2009 MAN drilling results assays indicates the presence of a disseminated NI-Cu PGE (platinum group elements) concentration build up extends beyond 600 meters in DDH PNI-09-024 and over 1000 meters in DDH PNI-09-025.  Geophysical surveys show that these conductive bodies are associated with the strongest Fluxgate TEM anomalies on the property,  in addition, strong responses to the BHEM surveys indicates late channel (high conductance channels) conductivity build up beneath the drill holes.

The surveys described below were used to model the interpretation of conductive anomalies on the property. The analysis concludes that the anomalies are deep, large and very compelling.

1. ZTEM Survey – has for the first time identified at depth the shape structure, and conductive zones of the mafic and ultramafic intrusions.
2. Ground TEM – proprietary long time constant, time domain electromagnetic surveys allowed for deep search (> 800 meters) for high conductance bodies commonly associated with Ni-Cu sulphides that have been missed by previous surveys methodologies.
3. Ground and Airborne Magnetic Survey’s - these survey’s help to define the magnetic bodies below surface that often correlate to the ultramafics and mafic rocks on the property.  In addition, UBC 3D inversions and Euler 3D inversions are employed to help determine the location of the form, internal structure, and deep kneels or feeder dykes associated with the intrusive bodies.
4. BHEM Survey – a borehole electromagnetic survey is performed down the drill hole to detect conductive anomalies within, beside and below the drill hole to aid in the correlation with the new high priority, long time constant, surface TEM survey results constraining more accurate location of the conductor.

One of the most exciting targets from the 2009 geophysical program was the identification of the location for drill-hole PNI-09-025 based on the initial results from the TEM surveys.  The hole was drilled to a depth of 1066 metres and terminated due to the limitations of the drill.  The BHEM (down hole geophysical survey) showed an increasingly large response towards an anomaly below the hole’s final depth.

Low-frequency borehole electromagnetic surveys (BHEM) were carried out in five of the 2009 drill holes, as well as seven older drill holes. A number of moderate to strong off-hole conductors were detected and are being evaluated as follow-up drill targets for the 2010 program. Three holes (07-001, 09-023 and 09-025) show anomalous increases in late time channels indicative of deep conductors below the base of the holes. These deep conductive zones correlate with high-priority long time-constant surface TEM anomalies.

Extensive geophysical work was conducted concurrent to the drilling program.  In particular, a new ground time domain EM system (full waveform streaming multisensor fluxgate array), was deployed extensively through the latter half of the exploration season.  This was the first instance of this technology being used in North American nickel exploration.  This ground based EM technology developed by Dr. Mark Shore (Magma Geosciences Inc.) provided Pure Nickel exploration team with the ability to collect low-noise late time data under challenging conditions and identify electromagnetic anomalies at greater than  800 metres depth.

Dr. Mark Shore is going to represent example of using of lower frequencies induction coil, SQUID and fluxgate sensors on the nearest PDAC in Toronto: http://www.pdac.ca/pdac/conv/2010/pdf/presentations/ts-mark-shore.pdf.

Instrumentation GDD Inc. (Quebec) announces its newest breakthrough in the field of geophysics with the Sample Core IP Tester, model Time Domain Low Voltage.
Made after the GDD IP Receiver, model GRx8-32, this new geophysical instrument is perfect for determining a core sample resistive properties. Tests done with the SCIP will determine the chargeability and resistivity of the diamond drill core or field. Knowing what are the physical properties of your sulfites, will help you plan the appropriate geophysical survey. Rugged, compact, inexpensive and easy to operate, the SCIP is built like a 1 dipole GDD IP Receiver.

The Ontario Prospectors Association presents: Ontario Exploration and Geoscience Symposium 2009 ”A Decade of Risks and Rewards” December 15^th & 16^th, 2009, Radisson Hotel, Sudbury, Ontario.

Geophysical presentations include:

Blaine Webster, Goldeye Exploration Ltd. / JVX Ltd.,  Application of 3D Spectral Borehole IP to Guide Drilling on the Big Dome Project, Tyrrell Township, Ontario

Joe Mihelcic, ClearView Geophysics Inc., The Ghosts of Geophysics Past, Present and Future

Pierre Gaucher, Instrumentation GDD Inc. Enhance Your Gold Exploration with the latest GDD 3D IP Receiver and the new GDD Portable Sample Core IP Tester

The Ontario Exploration and Geoscience Symposium is OPA’s annual symposium with workshops, a variety of speakers, poster displays and an exhibit floor. December 15^th & 16^th, 2009, Radisson Hotel, Sudbury, Ontario.

There is not final information but according to the preliminary  two geophysical speakers are going to be – Joe Mihelcic from ClearView Geophysics Inc., and Pierre Gaucher from Instrumentation GDD Inc.

GOLDEN, COLORADO — 12/03/09 — Lake Victoria Mining Company reports about the acquisition of its own Induced Polarization (I.P.) electrical geophysical prospecting system that will initially be used to target drill holes at the Company’s Singida gold project in central Tanzania.

At Singida, geologic mapping, underground sampling, trenching and detailed ground based magnetic surveys have defined a five kilometer long gold bearing quartz vein system. The Company is currently field surveying and clearing grid lines for conducting electrical I.P. surveys along this five kilometer mineralized trend.

I.P. surveys, by measuring the response from energizing the ground with high energy pulsating electrical forces, can locate at depth the mineralized centers and metal rich source areas which produced the gold veins observed in surface exposures. Locating the source areas and the geologic structures which controlled the near surface vein deposits will allow drill holes to be strategically placed along the five kilometer trend. The objective of the I.P. surveys is to locate drill targets and the objective of drilling is to rigorously define gold resources and reserves that are capable of supporting an economic mining operation.

Roger Newell, president of Lake Victoria said: “Having our own I.P. equipment will allow us to plan and execute our own surveys in a timely fashion. Last year we purchased our own state-of-the-art ground magnetic equipment; now having both geophysical systems will allow us to conduct ground magnetic and electrical surveys quickly and accurately and shorten the time to begin drilling. The sooner we can drill, the sooner we can advance the project towards engineering studies and production.”

Geophysical instrument engineering  company from Quebec promises the latest geophysical innovations in 2010 - NEW IP receiver with up to 32 channels, Enhanced GDD Induced Polarization Transmitters used in Master-Slave Dual Mode configuration which enable to transmit up to 4800 Volts, Enhanced GDD MPP-EM2S+ Multi-Parameter Probe with Bluetooth for measurement of magnetic susceptibility and conductivity.

Fugro has purchased the Falcon airborne gravity gradiometer from BHP Billiton and now operates four systems worldwide. To date, application of the systems by Fugro has been limited under the sale conditions to petroleum exploration. In April 2010 the Falcon system will become available for general use by mineral explorers for the first time, offering explorers a new tool in search for mineral deposits.

In Issue 142 of ASEGs “Preview” Greg J. Street (Fugro Airborne Surveys) reviews some of the more significant mineral exploration successes of the Falcon system to date.