Posts Tagged IP

IP or not IP? (notes about IP in transient EM)

Posted by on Tuesday, 28 April, 2015

by Alexander Prikhodko

During the last few years the topic about IP effect (induced polarization) in the EM (electromagnetic) transient method (mostly in airborne time-domain) has been actively raised by many authors through geophysical magazines, conferences and meetings.

Here we will look into the topic without formulas and deep theory for a better understanding of the IP effect by general users of electro-prospecting  methods.

The nature of the IP phenomenon is universal regardless of an electric field source inducing (causing) the phenomenon or a measurement way of the appearance. First of all, the IP theory is out of Maxwell equations solutions because the process is accompanied by mass transfer and connected with EM field transformations. In contrast to IP theory Maxwell’s equations deal with electromagnetic induction which the time-domain (transient) method is built from.

In the case of IP the term “induced” means “caused” and does not relate to the concept of EM induction.

The concept of Induced Polarization (a substance ability to separate opposite charges) incorporates different phenomenons but related processes that occur:

1) in heterogeneous fluids or in pores filled with fluids;

2) due to electrochemical processes.

These two phenomenons – electrokinetic (1) and electrochemical (2), is a key to understanding how IP is used in applied geophysics.

Electrokinetic processes occur on contacts between ionic conductive fluids and a solid phase.

Electrochemical processes occur on contacts, or surfaces, between phases with electronic (metallic) and ionic (non-metallic) conduction. This is fundamental when IP method used when exploring for sulfide mineralization, especially if the sulfides are disseminated as the IP effect will be stronger than for massive sulfides of the same volume because its surface area is less.

Historically electrochemical nature of IP phenomenon first investigated and used in geophysics by Conrad Schlumberger (published in 1920). Later, during further electronic industry development and equipment sensitivity and bandwidth increasing, IP effect began to be observed all over the geologic environment due to the possibility of measurement of rapid and comparatively weak IP signal of the electrokinetic nature.

Generally, the IP effect of both natures potentially may affect data obtained with any electro-prospecting method including inductive time-domain method, regardless that the strongest IP effect occurs in the geologic environment at galvanic (grounded) way of the current inducing and the voltage measuring.

So, the IP component in transient or time-domain data is a parasitic effect which is not under Maxwell’s EM theory. (By the way, in the widely employed original DC-IP method, the inductive component is considered as a source of noise.) There are some technical requirements to sensitivity, bandwidth and geometry of a time-domain system to get better the parasitic signal superimposed on the inductive, native to the method, component.

Fortunately the IP parasitic signal is opposite to the inductive secondary field component allowing to recognize it and separate out it in some cases from the measured total secondary field. The favorable condition to get IP component from time-domain data and investigate it is rapid decaying inductive secondary field, i.e. resistive environment in general is favorable, but there are cases  when a strong IP component is prominent in presence of long inductive decay.

Unfortunately the existing theories of the electrokinetic and electrochemical natures of the IP phenomenon are on a qualitative basis. It means there is no chance to get petrophysical or/and petrochemical parameters of the geologic environment and to classify the IP sources according to their nature. On practice, empirical approximations are used for the IP process description with limited controlled parameters (in particular, Cole-Cole formula and the corresponded parameters) despite the nature of the phenomenon. To our delight it enables creative and thoughtful geological interpretation of the IP data if we get it correctly.

Practical Inversion for Geoscientists

Posted by on Wednesday, 10 April, 2013

A short course on the why, how, and what of geophysical inversion

Presented by the B.C. Geophysical Society

This is a 2-day workshop consisting of 1 day of lectures (April 24th) followed by a 1 day hands-on workshop (either April 25th or 26th). Delegates can register for just the lectures or both the lectures and workshop.

Registration available until April 15th at:

Date: April 24th – 26th 2013

Address: SFU Downtown Campus; Vancouver BC

Registration: Registration is now open!  Please fill out attached pdf form (link below) and click submit.  Registration will be complete once payment is made via Paypal link.  Delegates are asked to choose one workshop day among April 25th or 26th.

Day 1 – Introduction to inversion
– Introduction to inversion in exploration

Reasons for doing inversion
Range of inversion options: magnetics, gravity, EM, IP-resistivity, seismic
Fitting geology and data

– Background on inversion

Joint and collaborative
The future of inversion

– Before inversion – forward modeling

forward modeling
petrophysics drives the story
complexity vs. adequacy

– Case studies

Potential fields

Day 2 – Workshop with Case studies
Multi-disciplinary teams will use geological, geophysical and geochemical data from two deposits (Babine Lake porphyry Cu-Mo, BC and Minto Cu, YK) to develop exploration targets. Teams will present their evaluations of the data to stimulate group discussion.

Inversion results for the available geophysical surveys will be presented to demonstrate state-of-the-art technology and best practices.
Sponsors for the short course are currently being solicited. Please contact Victoria Sterritt at for details. Proceeds go to the KEGS Foundation.
For those interested in more information about the short course, please email

Induced Polarization Survey in Ghana

Posted by on Saturday, 8 December, 2012

Castle Peak Mining Ltd. announces Promising Surface Sampling Results at the Dansuom Target on the Pow Concession at the Company’s Akorade Project in the Southern Ashanti Belt in Ghana, West Africa. the Reported Results Represent Approximately 25% of the Road Samples Collected to Date. Concurrently a Gradient Induced Polarization Survey and Subsequent Pole-Dipole Induced Polarization Survey was Completed in Order to Better Refine Drill Targets in the Area.

Highlights of the Sampling Include:

  • Channel POWCS008: 70.0m of 1.01 g/t Au including 26.0m of 1.76 g/t Au;
  • Channel POWCS007: 12.0m of 0.54 g/t Au;
  • Channel POWCS005: 2.0m of 2.38 g/t Au.

Highlights of the geophysical survey include several kilometer scale coincident resistivity and chargeability anomalies. Two of these significant anomalies are spatially associated with the large, 1,500m by 250m, Dansuom gold in soil anomaly defined by soil values greater than 0.2 g/t gold. (To see Figure 1: Anomalies in Dansuom Target Area, please visit the following link:

Commenting on the results Darren Lindsay stated, “Although dealing with a less than predictable rainy season this year, we have been able to forge ahead with geophysical surveying, mapping and sampling to better determine the resource potential in the Dansuom target area. Strong geophysical anomalies coincident with our existing geochemical anomalies and new road cuts exposing vein stock works, alteration zones and contact zones are showing the promise of this exceptional target.”

Update on Regional Exploration

A total of 690 samples for multi-element analysis have been collected across the Akorade project area, with approximately 300 samples remaining to be collected across the mineral licenses at 400m by 400m spacing. To date all samples from Enyinase, Bonsaso, Kedadwen and Dompem have been collected, while mapping and sampling still continues across the POW and Great Yorkshire licenses. Mapping from these efforts is being compiled to refine our existing base map.

Geology & Mineralization

The properties are underlain by NNE-SSW Birimian Age metavolcanics and Tarkwaian metasediments of the Ashanti Belt of southwestern Ghana. These rocks are intruded by two (2) chemically distinct granitic suites which consist of: 1) Belt associated Dixcove intrusive and 2) Basin associated Cape Coast intrusions.

Deformation and metamorphism of Birimian metavolcanics and Tarkwaian metasediments (conglomerates, arkose, sandstones, siltstones and shales) are related to the Eburnean II orogeny with five (5) distinct successive deformation phases, (D1 to D5) with D2 faults and D5 reactivation for major deformation events such as strike slip, dilatants breccias, quartz veins and lens networks with pinch and swells (boudinage) hosted within faults and shear zones.

Shear zones on the property are developed within the metavolcanics. The granitoid intrusions have been accompanied by hydrothermal activity evidenced by the numerous lenses of quartz veins and veinlets within the metavolcanics. The most prominent quartz structure, in a shear zone and within the metavolcanics on the Apankrah hills, has a NE-SW orientation and dips steeply to the southeast. The quartz vein, more than 1 metre in width and strike length of more than 100 metres is shattered and pyritized in few places.

The most favourable areas of gold mineralization in the Birimian and the Tarkwaian are found:

  1. In a major shear system in early Proterozoic rocks, e.g., Prestea and Obuasi
  2. In intermediate and mafic intrusions, mainly within the “greenstone” belts
  3. In mafic volcanics in some areas, especially in the Ashanti belt, e.g., Konongo
  4. In transitional zones between the belts and the basins
  5. The banket conglomerates of the Tarkwa district
  6. Oxide and laterite occurrences

The Bonsaso concession is dominated by well-foliated Birimian metasedimentary units. Detailed geological mapping of the concession is ongoing, but is hindered by the presence of a significant weathering profile. The geology is currently thought to be similar to that of the Iduapriem mine.

Gold mineralization in the area has been observed in shallow dipping quartz stockworks and veins. Quartz veins occur as a series of shallow dipping, thin, en-echelon quartz veins up to and greater than 10 centimetres wide. The veining is also associated with a quartz-pyrite alteration halo that extended several metres into the hanging wall and foot wall of the veins. This is thought to represent the type of deposit that typically forms along regional fault and fracture systems within Ghana, whereby fractures act as pathways for Au-bearing hydrothermal fluids. Precipitation of gold and quartz then results from changes in pressure, temperature and/or wall rock interaction. Mineralization is also associated with Tarkwaian conglomerates, probably of the Banket series and representative of placer mineralization, which is analogous to that at the Iduapriem mine. 

The New High Grade Epithermal Gold Deposit in British Colombia

Posted by on Wednesday, 5 September, 2012

Seabridge Gold announces that exploration drilling this summer on its 100%-owned KSM Project in northwestern British Columbia has discovered an epithermal style of gold occurrence which contains significant widths of higher gold grades including narrow veins with the highest gold grades found at the project to date. The claim blocks are in the Iskut-Stikine region in British Columbia, approximately 20 kilometres southeast of the Eskay Creek Mine.


Induced polarization surveying was utilized as final confirmation, prior to drilling, that the sulfide or mineralizing system at KSM was of a world class scale and could satisfy Noranda’s minimum exploration criteria.   A pole – dipole IP survey was conducted on 7 widely spaced lines and was designed for the best combination of depth penetration and resolution. It employed an “expander array”, consisting of four 100m receiver dipoles, two 200 m receiver dipoles and finally two 300 m receiver dipoles for a total array length of 1500 m.  The widespread strong chargeability and low resistivity responses detected in rocks beneath the Sulphurets thrust fault satisfactorily demonstrate the extent of sulfide bearing, altered rocks.  However, as is typical of the IP method, it does not differentiate between areas of strong pyrite but weak chalcopyrite (copper sulfide) mineralization or those with both pyrite and chalcopyrite.

On the contiguous with Seabridge’s KSM property Treaty Creek property (American Creek Res.) magnetotelluric survey carried out in the summer of 2011 (Quantec Geoscience). The survey revealed a large conductive body at depth which extends upward to the surface and can be mapped between MT sites 214 and 216.  This area contains gossanous outcrops along with surface mineralization and also includes the previously explored Orpiment zone.  The survey also shows a more prominent feeder extending over 3km from the large conductive body at depth.  This feeder is approximately 750m wide and extends to the location of the Copper Belle zone where another large conductive body (less than 200ohm-m) appears on the survey.  The north east tip of Copper Belle, a bulk-tonnage type gold-copper-molybdenum porphyry, appears to be located at the north east tip of this lowly resistive anomaly. Details..


KSM has proven and probable reserves totaling 38.2 million ounces of gold and 10 billion pounds of copper in four very large deposits which have an average grade of 0.55 grams per tonne of gold, 0.21% copper and 2.74 grams per tonne of silver. The new discovery has intercepts of gold and silver grades that are substantially higher. Drill hole C-12-01 encountered epithermal style mineralization in an entirely new zone at shallow depth and low elevation, called the Camp zone. This hole returned two 2 meter intercepts grading above 8 grams of gold per tonne (greater than 0.25 ounces of gold per tonne). A second hole, C-12-02, drilled 400 meters southeast of C-12-01, intersected 22.0 meters averaging 8.94 grams per tonne of gold and 41.6 grams per tonne of silver. This hole returned a 2 meter intercept of 66.7 grams of gold per tonne (more than 2 ounces per tonne) and 287 grams per tonne of silver (nearly 10 ounces per tonne). A third hole into this zone, C-12-03 drilled 900 meters to the northeast of C-12-02, returned 98.7 meters at an average gold grade of 2.11 grams per tonne including 17.7 meters averaging 4.41 grams per tonne of gold and an additional 6.0 meter intercept averaging 6.24 grams of gold per tonne.

Seabridge Gold CEO Rudi Fronk said the new discovery appears to have the potential to make a significant contribution to KSM’s already robust economics. “Obviously, we are at a very early stage in the discovery process. However, the Camp zone is readily accessible and has the highest gold grades found to date. All three holes into this new zone found excellent gold values,” he said.

“This is not the target we were looking for in this year’s program…we were exploring to find a high grade, copper-rich core and that work continues with encouraging results. Our original assumption was that neighboring Pretium Gold had the higher grade, epithermal (top) portion of the very large gold-copper porphyry system we see at KSM and that our property would probably host the high grade copper core of the entire complex at depth. The new Camp zone appears to be part of an epithermal system with chemistry similar to that found nearby at Pretium’s extraordinary Brucejack deposit. We intend to complete another six holes into the Camp zone this drill season to establish the orientation of this new discovery. At the same time, we continue to pursue several promising copper core zone targets. An additional exploration drill rig has been mobilized to site, bringing the total to three,” Fronk said.

read more..

The New VMS Discovery in the Ring of Fire

Posted by on Thursday, 16 August, 2012

MacDonald Mines Exploration Inc. announces results from the most recent drill program on the Butler 3 target on its Butler property located just 36 kilometres west of the Big Daddy Chromite deposit.

  • The last drill program hit zinc-rich massive sulphide mineralization with tenors typical of past and current producing VMS mines – the zinc rich sulphides are generally found on the periphery of these types of deposits
  • VMS systems typically get more copper-rich the closer one gets to the centre of extrusion
  • VMS mineralization identified on the Property suggests there are multiple centres of extrusion, and therefore the potential for multiple VMS deposits (i.e. a VMS camp)
  • Geophysics indicates there is ample room for deposits in excess of 20 MT
  • Company geoscientists believe the constraining geologic markers bounding VMS mineralization have been identified on the Property, and that future exploration should be able to vector into more copper-rich mineralization.

Butler 3 Section Showing Mineralized Zones

Geophysical Model

The current geophysical data set includes:

  • Airborne, Surface and Borehole Time Domain EM
  • Airborne and Ground Magnetics
  • Surface and Airborne Gravity
  • IP and Complex Resistivity

A model of this data constrained by the current mineralized intersections, geochemistry and geology indicates the potential of the Butler Property to host not only VMS occurrences of size but also multiple centres.Plan maps of this compilation for Butler 2 and 3 are below.

Each occurrence consists of an underlying copper-rich stringer zone that is separated by a ~20m massive black felsic “marker” flow from several overlying horizons of zinc-silver-copper massive sulfide. The footwall rocks are all intensely altered, characterized by widespread sodium (Na) depletion and more localized manganese (Mn) enrichment (typical of VMS camps like Sturgeon Lake).

Completion of Geophysical Survey at King Solomon Dome Property (Yukon)

Posted by on Saturday, 30 June, 2012

Kestrel Gold Inc.  announces the completion of a geophysical survey at Kestrel’s King Solomon Dome Property south of Dawson City, in the Yukon Territory (“KSD“).

The Survey is intended to map the geophysical properties of resistivity and chargeability of the subsurface down to a depth of 500 metres. SJ Geophysics Ltd. of Delta, British Columbia using their new Volterra-3DIP system in conjunction with a magnetometer survey over a grid approximately 1.6 km by 1.6 km, has been focusing on the area encompassing the Sheba and Mitchell workings which lie within a large gold geochemical soil anomaly. This second phase of deeper geophysical work is envisaged to give a much clearer (3D) picture of the morphology of structures, contrasting lithologies and additional potential drill targets at greater depths. The Survey follows on from the first phase of geophysical work conducted in 2011 which was successful in outlining a large chargeable IP anomaly centred in the area around the Sheba showing and trending towards the Mitchell Shaft to the north over a distance of approximately 1.2 km open along strike and extending to depth.

William Taylor, the Vice President Exploration of Kestrel comments: “We know from work done to date the importance of regional scale NNW trending D4 structures at KSD in relation to Klondike gold mineralization. This survey will help us better understand the other factors that have concentrated the gold and other path finder elements in this particular area where the signatures are so relatively high.”

A number of drill targets have already been outlined at KSD and the results of the Survey are anticipated to be received in advance of the Corporation’s planned 2012 diamond drill program.

King Solomon Dome is a 4050 foot peak in the Yukon Territory of Canada.  It is believed to be the source of the gold fields that sparked the Klondike Gold Rush in the early 1900’s (link to Yukon Gold Mining – Klondike).  Kestrel has an option to earn 100% interest in four individual properties in the King Solomon Dome. The option will require Kestrel to make staged payments totaling $920k over a period of 4 years, issue 150k shares and fund exploration expenses of up to $100k.


Previous soil sampling within the project area claims had encountered 3 main anomalous zones, each at least 1.0km in length and varying from 25 metres to 400 metres in width, with soil geochemical values of up to 965 ppb Au associated with occasional highly anomalous arsenic, antimony and lead. This metal signature is common to White Gold area mineralized zones such as the Golden Saddle and Arc deposits held by Kinross Gold (formerly Underworld Resources). Recent trenching of these anomalies has encountered mineralization including narrow high-grade zones often containing visible gold with grades ranging up to 14,700 ppb (14.7g/t) Au over 1.9m, 8100 ppb Au over 1.9m and 40,670 ppb Au (40.7 g/t) over 0.7m; as well as broad intervals with grades such as 1622 ppb (1.6 g/t) Au over 8.4m and 2242 ppb (2.2 g/t) Au over 18.2m.

Ground gravity survey in the Ring of Fire

Posted by on Tuesday, 28 February, 2012

MacDonald Mines Exploration Ltd. announces results of a ground gravity survey over the Company’s VMS targets on the Butler Property in the Ring of Fire.

The presence of density anomalies associated with and adjacent to the feeder/stockwork sulphides intersected to date on Butler 3 suggests either:

  • An  increased presence of sulphides or
  • A different rock type of greater density or
  • a combination of both

The measurement of gravity is an effective technique for defining geometry, structure, and a proven tool in mapping intrusions in sedimentary and volcanic terrains. The use of ground gravity surveys, have historical success in the search for volcanogenic massive sulphide (VMS) deposits.  The technique has been attributed to the discovery of the Sunridge Gold Embra Derho deposit in early 2007 (Approx 62.5 m/tonnes) in Eritea.

The gravity data collected over the Butler property by the Ontario Geological Survey (“OGS”) and Geological Survey of Canada (“GSC”) survey confirmed the Company’s interpretation of a large mafic – ultramafic package that exists along the eastern portion of the property (Butler 5).  This insight prompted MacDonald to utilize the technique over the highly prospective Butler 3 zone.

Ground Gravity Survey

At Butler 3, three distinct density anomalies coincident with anomalies from other geophysical techniques have been identified by Abitibi Geophysics.    These density anomalies add credence to the interpretation of a large VMS system in the Zone identified as Butler 3.  This system is associated with the stringer materials in diamond drill hole BP11-Cu06 which intersected 167 metres of 0.39% Cu and 1.13% Zn. Results for Butler 4 and Butler 5 are pending and data collection continues as exploration is ongoing.

Butler 3 – Characteristics of a Volcanic Hosted Massive Sulphide Deposit (VMS)

The Butler 3 targets are quantified by the following geological characteristics:

  1. The volume of alteration is exceptional, indicating that a very large volume of hydrothermal fluid discharged in this region.
  2. Butler 3 is contained in a felsic-dominated sequence.
  3. The alteration zone is Cu-enriched, and the Cu content increases stratigraphically upwards towards the mineralized horizon.  Cu tenor is high (greater than 3%).
  4. Zinc mineralization is less than expected – indicating a higher temperature system (Cu-enrichment).

Geophysically the targets have physical properties commonly identified with massive sulphides.  These are:

  1. The Butler 3 targets are Electrically Conductive – indicative of metallic content.
  2. Elevated magnetic susceptibility – signifying structure and potential sulphides.
  3. Dense – suggesting the presence of sulphides.

In summary Butler 3 exhibits a multitude of exploration vectors and proximity indicators of a VMS system.  These include but are not limited to:

  • Geophysical properties – conductive, dense, magnetic.
  • Mineral zonation – stringer mineralization with elevated Cu values have been intersected over significant lengths.
  • Alteration Indicies – the drilling has identified a large alteration system with sodium depletion.  This is an indication of lateral distance from the core of the discharge zone.
  • Mineral chemistry vectors – these are coincident with the geophysical anomalies (conductance and density)
  • Structural controls – the stringer zone is capped by a key marker horizon comprised of a siliceous relatively impermeable, black felsic unit

Deep Penetration and High Resolution IP Resistivity Survey

Insight Geophysics Inc. has been retained to apply their technology over Butler 3, Butler 4, Butler 5 and the Sanderson properties in the Ring of Fire.  This array is currently being utilized in the Ring of Fire by Noront Resources who have commented on the success of the technique to identify zones of nickel sulphide in their recent press release.

Preliminary results of this survey over Butler 3 have confirmed chargeability anomalies coincident with the gravity results.  Chargeability measures the ability of the sub-surface to temporarily maintain an electrical charge – sulphides are typically chargeable.  The survey is expected to be completed in early March, 2012.

High grade Au results with ground IP and mag surveys

Posted by on Thursday, 9 February, 2012

Benton Resources Corp. provides an update on its Sewell-West Timmins Project in northwestern Ontario, located 60 km west of Timmins and 40 km west of Lakeshore Gold’s Timmins Mine.

During the summer and fall of 2011, a 48 km grid was established over the centre of the property and prospecting, mapping, IP and ground magnetometer surveys were completed. This work identified several areas of anomalous gold mineralization, the most significant being the “Baseline Showing”, where 40 surface grab samples collected over a strike length of 300m returned values ranging from trace to 5.09 grams per tonne Au.  Mineralization at the Baseline Showing is hosted within a NNW trending shear zone consisting of strong carbonate altered mafic and lesser ultramafic volcanic rocks and highly altered sulphide-rich chert-magnetite iron formation.

In December, 2011, an eight-hole, 1,476 metre drill program was completed to test the Baseline Showing with significant results including 94.018 grams per tonne (gpt) gold (Au) over 1.1m (hole SW11-03), 1.38 gpt Au over 2.3m (hole SW11-06) and 1.44 gpt Au over 1.1m (hole SW11-08).  Holes SW11-01, 02, 04, 05 and 07 returned trace to weakly anomalous gold values. The mineralized intervals represent core lengths.

The Company is encouraged with the early high grade results intersected in SW11-03 and is currently reviewing all data from the 2011 work programs.  The next exploration program will target the favourable gold-bearing horizon to the north and south of drill hole SW11-03, as well as looking at other zones which have been identified on the property.

Large IP Anomaly at Baffin Island Gold Property

Posted by on Friday, 3 February, 2012

Commander Resources Ltd. announces that results from the deep sensing, 3-D Induced Polarization (IP) Survey conducted at the Kanosak gold prospect in the 2011 field season have been reported. The survey results indicate the presence of a steeply dipping, cross-cutting zone of high chargeability and low resistivity below gold anomalous strata bound sulphide mineralization hosted in flat lying sediments over a 3 km strike length. The IP anomaly is interpreted as a possible feeder to the extensive surface mineralization. Trenching and shallow drilling has previously found widespread free gold in quartz veins and associated with disseminated arsenopyrite and pyrite.

The survey was conducted by Abitibi Geophysics of Val d’Or, Quebec, who also prepared all plans and interpreted the results. The report states that a large, sub-vertical anomaly commences about 150 metres directly below the surface gold showings at Kanosak. The IP chargeability anomaly underlies the entire 3 km strike extent of the grid. Additionally, the anomaly is open to the south, with the strongest response at the southern most grid line.

The report states that the intensity of the anomaly increases with depth, with primarily background chargeability values (15-30 mv/V) from surface to 50 metres, increasing to some of the highest recorded values (300 mv/V) at 150 metres. The high values are interpreted to be attributable to sulphides, as there is no graphite recorded in this area.

The IP results are presented with maps on the Company’s website. Three plan maps show chargeability values at 50-100-150 metre depths and a surface interpretive plan shows the IP anomaly, along with completed and proposed drill holes. Most of the holes (shown in grey) were drilled west of the target or were too shallow to reach the top of the interpreted source. This previous drilling was designed to test surface gold showings and early stage, shallow (less than 75 metre depth) IP response. Proposed holes, (shown in green) are designed to test the new, deep responses.

The interpretation of the IP response from the deep, 3-D survey indicates that a very large, strong disseminated sulphide source dips sub-vertically below 150 metres depth from surface. This may be the feeder system which produced the very high grade, but irregularly distributed gold veins scattered over 3 km’s on surface at Kanosak.

The chargeability anomaly is associated with a resistivity high, which is also reflected in the surface showings at Kanosak. Here, gold is associated with the arsenopyrite and minor pyrite, which are good IP sources. As the IP source is associated with magnetic lows, the source is not expected to be magnetic pyrrhotite or magnetite.

A 3,000 metre drill program has been proposed to test these strong, deep targets. A camp is established and permits are in place.

Geophysical Survey Results at La Vereda Concession in Colombia

Posted by on Friday, 3 February, 2012

CB Gold Inc.  provides summary geochemical and geophysical survey results from the La Vereda Concession at its Vetas Gold Project, District of Santander, Colombia (“Vetas Gold Project“), located 10km south of AUX’s La Bodega and La Mascota deposits. The 80% owned La Vereda property is covered by a concession contract expiring in 2037.

La Vereda Geophysics Survey Results:

The Company conducted an Induced Polarisation (“IP”) geophysical survey at La Vereda, identifying a major anomaly characterized by high chargeability and low resistivity (see attached 3-D images – additional plan view sections can be viewed at Surface mapping and geochemical sampling had identified quartz veining and stock work zones similar to other properties at the Vetas Gold Project.

The geophysics anomaly at La Vereda is approximately 2,000 meters long and up to 700 meters wide and is interpreted as an extension of the epithermal style mineralization found at surface, with the high chargeability indicating the presence of potential sulphide mineralization at depth. The anomaly strikes northeast / southwest, similar to many mineralized structures in the Vetas – California District.

Mapping to the north of the property boundary has identified an outcropping zone of quartz veins, approximately 400-500 metres wide, that strikes northeast and projects under cover directly into the geophysical anomaly identified at La Vereda. Summary results from surface channel samples across this vein cluster include gold grades up to 26.3 g/t Au (Additional geochemical results can be viewed at Drilling will target potential mineralization with up to 10 initial holes planned into the main zones identified by the survey upon receipt of drilling permits.

La Vereda Geochemistry:

All the samples taken by CB Gold at its La Vereda Concession were analyzed by ALS Chemex Labs in Lima, Peru. The Company has a standard QA/QC program which includes blank material, certified reference material and duplicate samples. The QA/QC program has been reviewed by various independent consultants experienced in QA/QC work.

Fabio Capponi, Chief Executive Officer, noted “The results of the exploration work at La Vereda show the potential of this property to be an exciting additional target for the Company and we plan to commence drilling as soon as possible to test the extensive geophysical anomaly”.

Testing IP anomaies on Rice Lake Gold Belt, Manitoba

Posted by on Monday, 23 January, 2012

Harvest Gold Corporation announces that a diamond drilling program is set to commence on its 100% owned CUD claim Property, located 8-kms east of San Gold’s operating gold mine in the Town of Bissett, Manitoba.

The drill program will test two strong Induced Polarization (IP) geophysical anomalies associated with a shear zone developed within volcanic rocks of the Rice Lake Gold Belt. The favourable volcanic package that hosts the San Gold 1 zone and San Gold # 2-3 zones extends onto our property.

A 9.3 km IP survey was completed last summer by Abitibi Geophysics outlining six strong chargeability anomalies (C-01 to C-06) and four discrete anomalies (C-07 to C10). The most promising targets are C-04 and C-05 which form a somewhat continuous east-west trend across the grid. Anomaly C-04 is the strongest chargeability anomaly observed on the property.

A prospecting program was completed in the fall, following up the IP targets recommended by Abitibi Geophysics. The C-04 IP anomaly comprises quartz vein material within a silicified and sericitized altered shear zone. Two holes are planned to test the strongest conductivity sections of this target (see Figure 2).

Airborne magnetic and ground IP: 32.6g/t Gold in Northwestern Ontario

Posted by on Monday, 23 January, 2012

Northern Superior Resources Inc. announces that it has defined a potential 4 km fertile section of the Stull-Wunnimun fault in the Wynne Bay area of its 100% owned Rapson Bay gold property. All seven early exploration drill holes (1,850 m) contained intersections that returned positive assays for gold above background levels of 100ppb, including an intersection of 32.6 g/ t gold over 1.0 m.

A total of 32 different mineralized zones were intersected within a variety of volcanic and metasediments with lengths ranging from 0.5- 9.0m clearly indicating the fertile nature of this target area.

This area of interest occurs within a splay of a southwest fault associated with the highly prospective Stull-Wunnimun fault. This fault extends west-northwest from the Wynne Bay area to the Monument Bay gold deposit, 28 kilometers to the west-northwest of Wynne Bay. The Wynne Bay area has a history of gold exploration where multiple gold showings have been previously reported, including a historic outcrop sample of 1.65 ounces per ton. It is important to note that a northwest trending Wolf Bay shear zone also extends across the property to the Little Stull Lake gold deposit.

In addition to the diamond drilling, Northern Superior’s 2011 exploration program in the Wynne Bay area included: a) an airborne geophysical survey (covered the whole property); b) glacial sediment sampling; c) prospecting; d) trenching; and e) ground geophysics. This work has identified multiple gold exploration targets that remain untested over a 4km distance . These targets are based on: a) the distribution and concentration of gold grains including a sample that returned 48 pristine grains; b) a bedrock grab sample that assayed 6.28g/t gold from a highly altered metasediment ; and c) multiple IP anomalies.

Geophysical Program at Rubik Gold Project in Albania

Posted by on Thursday, 1 December, 2011

Golden Touch Resources Corp. announces that a ground geophysical program has commenced on its Rubik Gold Project in Albania.

The program includes: Induced polarisation (IP) chargeability, resistivity and ground magnetic surveys and is supplemented by a program of geological mapping and surface sampling along the geophysics grid lines.

The program will cover a prospective greenstone belt, trending eastwards from the Gjazuj Prospect, for a distance of up to seven kilometres.

The area being investigated includes six separate anomalous “gold in soils” or “gold in stream sediments” areas. Golden Touch is of the view that the anomalous areas could represent the outcrops of further, steeply-dipping, gold bearing shear zones of the type located by drilling at Gjazuj.

The mineralization is spread over a shear zone ranging from 6-30 metre wide, dipping at around 30 degrees to the north and subcropping below hillslope scree typically 1-3 metres thick.

Given that the mineralization comes virtually to surface and the generous width of the shear zone indicated to date, would suggest that there is an opportunity here for the Company to develop an open pit mining operation.  Hence Golden Touch’s objective is to define the available resources above 100 metres initially. The drill program will step in both directions along strike until the deposit has been defined.  The strike potential of targets over 6kms, suggest that there is considerable potential for the Company’s exploration to ultimately define a significant open pit gold deposit.

The drilling at Gjazuj has outlined at least nine, separate, steeply-dipping, mineralized shear zones, striking NW – SE. The Gjazuj shear zones coincide with one of the anomalous areas and the geophysics program will investigate five more anomalies, with the view of assisting the targeting of a second round of drilling. Based on the core logging at Gjazuj, Golden Touch expects that the magnetics and resistivity will assist in mapping the geology and tectonics (structure) of the area and it is anticipated that the chargeability will outline areas of sulphide mineralization. The core logging and mineralogy work has indicated that the gold mineralization is closely associated with sulphides introduced during the later stages of the tectonic, alteration and mineralisation history of the area.

The geophysical traversing is to be undertaken along one kilometre long lines at a spacing of 200 metres. Implementation of grid and line clearing by a topographical contractor ahead of the geophysics program, is already underway.

The Company geologists have already commenced a program of geological mapping along each grid line and they are channel sampling any mineralized exposures that are identified.

The geophysical program is being undertaken by CFT Engineering Geophysical & Geological Services, from Turkey. The crew is on site and has started work.

Ken Chapple, President of Golden Touch, stated that, “I look forward to the geophysical surveying rapidly delineating gold targets and fast tracking evaluation of the highly prospective greenstone belt to the east of the Gjazuj Prospect. The anomalies being tested are similar in nature to the Gjazuj anomaly where drilling has intersected at least nine separate gold mineralized shear zones”.

Geophysical Survey Results That Extend Hope Brook Mineralized Structure

Posted by on Wednesday, 9 November, 2011

The Titan 24 geophysical survey by Quantec Geoscience Ltd. indicates that the mineralized structure extends along strike southwest of the old Hope Brook mine area for at least one kilometre and to depths of at least 400 metres. – Induced polarization (IP) surveys done by Castillian north of the Hope Brook deposit suggest the Mine zone has been offset to the north along a fault and potentially extends much further northeast than previously thought. – Grab samples taken from outcrop proximal to this potential northeast extension returned values of up to 168.9 g Au/t.

Castillian Resources Corp.  announces the results from the Quantec Geoscience Ltd. (“Quantec”) Titan 24 geophysical survey (“Titan 24” or the “Survey”) and the Castillian induced polarization (“IP”) surveys completed at the Company’s Hope Brook gold property located in southwest Newfoundland. These surveys are described in a press release by the Company dated June 28, 2011. In addition, Castillian has completed a prospecting and mapping program along approximately 8km strike length of the mineralized structure extending from about 1 km northeast of the open pit southwestwards through historical showings in the Chetwynd and Chetwynd South areas.

Prospecting has identified a number of occurrences of gold in bedrock along the 8km strike length, including the potential northeast extension where one sample returned 168.9 g Au/t (Figure 2). Several samples also contain significant Cu values up to 10.2% Cu. A total of 213 samples were taken, of which 42 returned values of 0.5 g Au/t or greater.

Geophysical characteristics of Porphyry Copper Discovery at Tulameen

Posted by on Thursday, 20 October, 2011

Leonard W. Saleken, Chairman of Goldcliff Resource Corporation reports that Goldcliff has made the first significant porphyry copper ore grade discovery in the Copper Mountain mining district in decades. With surface samples highlighted by 0.655% copper – almost double the current reserve grades at the Copper Mountain Mine – and 1.3 grams per tonne silver, the Trojan showing is part of the Bolas anomaly, which is located in the Whipsaw target on the Tulameen property in the Copper Mountain mining district near Princeton, BC, Canada. The Tulameen property is 100 per cent owned by Goldcliff.

The three-pronged Bolas anomaly also contains the Eagle showing, which is highlighted by 0.175% copper and 1.0 grams per tonne silver. The copper mineralization on both the Trojan and the Eagle showings is chalcopyrite with malachite, and the iron sulphides are pyrite and pyrrhotite along with magnetite. These showings are situated on surface, above the substantial Bolas deposit-style chargeability anomaly. The Bolas anomaly is 2,000 long by 1,200 metres wide, and merges to form an area of 1.5 square kilometres at about 300 metres.

The Whipsaw alkalic porphyry copper-silver target area is located along the Copper Mountain south-west copper trend, approximately seven kilometres south-west of the Copper Mountain ore bodies. The Copper Mountain mineral reserves are 232,776,000 tons grading 0.36% Cu, 0.09 Au and 1.25 g/t Ag. The Trojan and Eagle showings are associated with the Bolas anomaly, which contains disseminated sulphide mineralization in the 3 to 5% range.

Bolas 3-D IP Anomaly

The deposit-style Bolas chargeability anomaly is a disseminated iron sulphide body that is located near surface and extends to an estimated depth of 500 metres in Upper Triassic Nicola Group rocks. The Bolas anomaly measures approximately 2,000 meters in a northwest direction by about 1,200 meters southwest. At a depth of around 300 meters, the anomaly merges to form a chargeable body of the order of 1,800,000 square meters or 1.8 square kilometres in size. The iron sulphide content of the rocks within the Bolas anomaly is estimated to be 3 to 5%.


The Bolas chargeability anomaly is a three-pronged star feature with a vertex centre and three end nodes that are referred to as the Whip, Elk and Eagle node areas of chargeability. Close to the surface, the chargeability response millisecond (ms) levels are weak to moderate. With increasing depth, the chargeability response millisecond levels become stronger and begin to merge at about 150 meters in depth. As depth continues to increase, the chargeability star features ultimately merge to form the continuous chargeability anomalous area. The chargeability values in the Bolas anomaly reach their maximum (25 to 30 ms) at about 300 meters below surface and then begin to fade to around 20 to 25 ms at 500 meters.

Whipsaw Target Area

Magnetic Environment

The most visible magnetic feature of the Whipsaw Target is a strong, broad, crescent-shaped magnetic high that fills more than half of the area. Inversion of the ground magnetic indicates that the deep-seated, crescent-shaped magnetic high is consistent with a deep-seated magnetic intrusive rock. A similarly intense, broad crescent-shaped magnetic high in the Copper Mountain area corresponds with mapped diorite intrusive rock and suggests that the magnetic high in the Whipsaw area may well be caused by the same rock type at depth.

The Whipsaw crescent-shaped, magnetic high partially surrounds a subcircular magnetic feature that is low, compared to the crescent-shaped high, but higher relative to magnetic background seen to the north. Once again, a similar pattern can be observed in the Copper Mountain area. There the subcircular magnetic feature corresponds with rocks mapped as monzonite and syenite, suggesting that the deep subcircular magnetic feature at Whipsaw may also be caused by a similar, less magnetic rock type. Strong chargeability anomalies occur within the subcircular magnetic feature.

Resistivity Data

Analysis of inverted resistivity data, with help from chargeability and magnetic inversions as well as magnetic intensity, indicates that the Princeton/Nicola contact may be vertical to sub-vertical and that the Princeton Group rocks could vary from about 150 to over 500 meters in depth, possibly over Nicola Group rocks. This may mean that the area of Princeton rocks could be down-dropped relative to the Nicola rocks across a fault-forming graben. If this is case, the deep moderate to weak chargeability anomalies seen in the area of Princeton rocks may then reflect the tops of chargeable material buried within Nicola rocks.

IP and magnetic surveys for polymetallic-gold in Southwest Mongolia

Posted by on Wednesday, 12 October, 2011

Erdene Resource Development An IP gradient array survey over the Altan Nar prospect outlined chargeability and associated resistivity anomalies in some instances over 1 kilometre in length, which are proximal to polymetallic-gold-in-soil anomalies and epithermal veins at surface.

The company announces results from the first drill program at the Company’s 100% owned Altan Nar (Golden Sun) property in southwest Mongolia. These encouraging polymetallic-gold assay results are from a shallow, four-hole drill program, focused on epithermal-style gold, silver and base metal mineralization.


  • Target area measuring 3 kilometres x 2 kilometres contains multiple prospects defined by geochemistry and geophysics with several gold-bearing epithermal-style quartz vein/breccia zones;
  • Initial hole intersects 55 metres of 1.02g/t gold and 12g/t silver, including 23 metres of 2.07 g/t gold and 23 g/t silver;
  • 70 metre-wide alteration zone with multiple gold-bearing zones intersected in four holes over 100 metre strike length, open to the north, south, and at depth;
  • Gold-bearing epithermal quartz breccia system has been tested to vertical depth of 85 metres with geophysical anomalies suggesting continuity and local intensification at depth.

Exploration Plans

Additional in-fill soil sampling to better define the regional extent of the soil anomalies at Altan Nar is underway as well as detailed geological mapping which will further refine the geological setting and controls for the epithermal mineralization. The company is also extending the regional magnetic survey (100 metre line spacing) to aid in interpretation of the geological setting. Additional geophysical work over the central portion of the Altan Nar prospect is currently underway and includes a detailed magnetic survey (25 metre line spacing), an extension of the existing IP gradient array (100 metre line spacing) and additional dipole-dipole IP lines. The expanded geophysical program will be used to refine drill targets for future drill programs. Additional geophysical and soil geochemical information is expected to be received throughout October and early November. Additional drilling is expected to commence on completion of the above work programs.


IP/Resistivity Survey at Copper-Gold-Silver Project in Turkey

Posted by on Sunday, 2 October, 2011

Empire Mining Corporation announces that an IP/resistivity survey has commenced at the newly identified Southwest Zone of the Demirtepe copper-gold-silver and molybdenum project in Turkey, with the aim of identifying the possible location of the source porphyry system that is believed to be the driver for the skarn-hosted mineralization at Demirtepe.

A total of 20 line kilometres is planned to cover an area of 3.5 km2 in nine east-west and one north-south profile each about 2.0 km long. Time-domain dipole-dipole surveying will be used with a six dipole array, with line spacing of 200 metres. A map is available at the following link:

Recent sampling at the Southwest Zone has identified a continuous copper-gold anomaly currently about 1.8 km long and up to 800 metres wide and still open to the southwest; with elevated copper levels in soils broadly coincident with elevated gold. Rock sampling results include 4.68% copper, 5.58 gpt gold and 59.3 gpt silver from wollastonite bearing boulders and 3.2% copper in garnet skarn boulders with copper oxide staining.

The new Southwest Zone is located approx. 1 km to the southwest of the Main Zone where drilling by Empire has encountered significant grades and intervals of copper-gold-silver and molybdenum skarn mineralization, including the discovery hole which intersected 47.53 meters of 2.02% Copper, 0.96 g/t Gold and 21.64 g/t Silver, including 8 meters of 9.1% Copper, 4.68 g/t Gold and 95.3 g/t Silver.

The Southwest Zone is interpreted as having formed the basement below the Demirtepe Main Zone deposit which then became detached. This view is supported by higher temperature signs of epithermal style quartz with chalcopyrite and pyrite. The identification of a basal detachment fault at the bottom of the Main Zone led to the discovery of the Southwest Zone.

The next phase of drilling at Demirtepe will be focused on the Southwest Zone.