Galym Nurjanov (a head of JSC “National exploration company “Kazgeology”) has held a press conference at RSU “Central Communications Service for the President of the Republic of Kazakhstan” and reported about success in investments attraction in the mineral exploration sector of Kazakhstan economy.
Over the past two years the four major foreign investors came to Kazakhstan – the Australian-British concern “Rio Tinto”, a South Korean corporation “KORES”, the Australian company “Iluka Resources” and the German investment fund “ULMUS FUND”. These companies are willing to invest into the mineral exploration sector over $ 5.5 billion tenge. Airborne geophysical surveys are going to be started soon in connection with Rio Tinto and Iluka Resources projects. The advanced airborne geophysical technologies including VTEM and ZTEM which are used right now in Kazakhstan, have been brought by Canadian company Geotech Ltd.
“INTEGRATING NEW TECHNOLOGY WITH HISTORICAL DATA, GEOLOGICAL INTUITION AND A LITTLE LUCK, COMPANIES ARE FINDING SUCCESS WHERE OTHERS HAVE NOT”
E&MJ News published an article by Steve Fiscor where some factors of new mineral deposits discoveries have been outlined – these factors include applying modern geophysical technologies. The author provides some examples – airborne EM (VTEM, ZTEM), airborne gravity gradiometer, and airborne radiometric surveys which played key role in discoveries of mineral deposits.
“All of the discoveries were in the zone of other major discoveries, but most of them had been overlooked for one reason or another. The motivation could only be attributed to a geologically motivated hunch. New technology in the form of deep-penetrating airborne surveys allowed ground-based geophysical surveys to target undiscovered anomalies. Combining the new information with what they knew historically, exploration geologists were able to improve the drilling programs to quickly determine a resource.”
The next discoveries made with airborne geophysical technologies:
Albany Ultra-pure Graphite – VTEM survey
The Balboa Discovery at Cobre Panama – ZTEM survey
Kennady North Kimberlite Discoveries – airborne gravity gradiometer survey
PLS High Grade, High Techand Contrarian – airborne radiometric survey
It may just look like an enormous, flying spider web towed behind a helicopter, but the ZTEM airborne geophysical survey system has the potential to identify giant porphyry copper deposits and features of other large ore deposits up to 2000 meters below the surface.
Z‐Tipper Axis Electromagnetic (ZTEM) is an airborne electromagnetic survey system which detects anomalies in the earth’s natural magnetic field. These disruptions are caused by zones of rock that conduct or resist electrical current more than the surrounding rock, like ore deposits. The proprietary technology belongs to Canadian company, Geotech, who have flown over 250,000 line-kilometres with ZTEM in under 4 years.
Geotech Ltd. is a Canadian airborne geophysical survey company that began operations in 1982. The company developed the now well-known VTEM (the versatile time-domain electromagnetic) system in 2002.
The helicopter version of the airborne Z‐Tipper Axis Electromagnetic (ZTEM) system was introduced into commercial service by Geotech in 2006-2007, and the less-expensive fixed-wing (FW ZTEM) system was introduced in 2010-11.
How ZTEM works
ZTEM specifications 300×225 Hunting for Giants: An Introduction to ZTEM Surveys in Mineral Exploration exploration methods ZTEM vtem uranium kimberlite exploration Geotech electromagnetism copper porphyry airborne geophysics
Flying spider web: the airborne loop of the ZTEM system (Geotech)
ZTEM is a type of electromagnetic (EM) survey to measure variations in the electrical properties of rocks.
EM surveys try to identify bodies of rock that conduct electricity well, like massive sulfide bodies of copper or nickel ore, or rocks that resist carrying current more than their surrounds, like the silicic alteration found in the core of porphyry deposits.
ZTEM surveys are different to other commercial EM systems because they measure variations in naturally-occurring EM fields rather than introducing an EM field into the ground and measuring the responding field, like VTEM.
Instead, ZTEM measures variations in the naturally-occurring or passive magnetic fields produced by thunderstorms around the world. This magnetic field is planar – constant in all directions – but areas of highly conductive or very resistive rock will cause measurable disruptions.
ZTEM surveys are designed to map resistivity contrasts to great depths, exceeding 1-2km, making ZTEM well-suited to finding porphyry-hosted and structurally-controlled exploration targets at depth.
What does a ZTEM survey look like?
The ZTEM system is transportable, able to be packed into small units which can be shipped around the world. There are two key pieces of equipment to the system, an airborne loop and ground receivers.
The airborne loops can be towed behind a helicopter or a fixed wing aircraft. The loop itself is a little over 7m across and looks a little like a giant, red-rimmed spider web. It is towed behind the aircraft at a height of around 100m above the ground to measure the vertical component of the magnetic field.
A 75-90m cable attaches the loop to the aircraft. The cable separates the loop from the vibrations of the aircraft and transmits the collected information back to the receivers in the plane or helicopter.
On the ground, base stations are set up in the survey area to measure variations in the horizontal magnetic fields.
GPS receivers are used on the coil in the air and also on the ground to keep track of the orientation of each of the parts, with respect to each other and the earth’s magnetic field.
A few Geotech case studies
Copper-porphyry, Alaska, USA
ZTEM was tested over a section of the world-class Pebble calc-alkalic copper-gold molybdenum porphyry deposit located in the Bristol Bay region of southwest Alaska in 2010. Some of the richest parts of the Pebble deposit are buried under up to 600 m of volcanic and sedimentary cover.
With careful processing, ZTEM was able to identify several of the distinctive alteration haloes found around the porphyry deposits, with more detail at depth than other systems.
ztem pebble Hunting for Giants: An Introduction to ZTEM Surveys in Mineral Exploration exploration methods ZTEM vtem uranium kimberlite exploration Geotech electromagnetism copper porphyry airborne geophysics
2D Resistivity cross-section over Pebble porphyry deposit in Alaska (Geotech)
Uranium deposits, Athabasca Basin, Canada
ZTEM tests were flown over unconformity-type uranium deposits in northern Saskatchewan, Canada, in 2008. The results correlated with known geological features to below 500m depth, penetrating through the thick cover materials to identify defining features in the basement rocks.
Kimberlites, Northwest Territories, Canada
A ZTEM survey flown over the Drybones Kimberlite near Yellowknife in NWT, Canada, was able to differentiate between diatreme (consolidated kimberlite) and the host rock buried under 100m of conductive cover sediments.
Several ZTEM case studies have also been published in peer-reviewed journals, for example:
Bellhaven Copper & Gold Inc. reports the commencement of the previously announced ZTEM (airborne electro-magnetics) survey over the entire La Mina property (1,800 Ha). The survey is also being extended to include an adjacent concession, which the Company is currently in discussions to acquire. The work is contracted to Geotech Ltd., a Canadian geophysical survey company specializing in leading edge airborne technology. The survey is designed to help refine the targets at La Mina, with a particular emphasis on the Garrucha and Cristalina target areas.
The helicopter-borne geophysical survey will result in approximately 132 line kilometres of data along east-west lines, spaced at 200 metres. The Z-TEM Electromagnetic (EM) system is an innovative technique making use of naturally occurring or passive EM fields from worldwide thunderstorm activity as the source of transmitted energy. The passive source combined with a proprietary receiver design, advanced digital electronics, and signal processing results in low noise levels, exceptional resolution, and unparalleled depth penetration. It has been used successfully to identify and map porphyry style mineral systems from Alaska to Chile.
Patrick Highsmith, Bellhaven’s CEO, commented on the program: “We are pleased to bring the ZTEM technology to the Middle Cauca Belt for the first time. It is a proven technique for porphyries in the Americas. This will enable us to prioritize existing geochemical and magnetics anomalies, including on concessions that we are in negotiations to acquire. This is a very cost effective tool that adds immediate value in an emerging mineral district such as La Mina. By sharing the mobilization and some of the administrative costs with neighboring explorers, we have made it even more cost effective.”
Discussion of ZTEM Survey
The survey is expected to identify conductive and resistive features that are associated with large mineral systems such as gold-copper porphyries from surface to considerable depth. The electromagnetic data is sensitive to sulfide minerals, as well as silicification and clay alteration; all of which are associated with the porphyry and epithermal deposits in the Middle Cauca Belt. This will be an important addition to the magnetics data that drove the initial discoveries. The EM data will advance the geologists’ knowledge of the known resource areas, particularly at depth, but it will also upgrade the targeting arsenal elsewhere on the property. This work will also enhance understanding of large structures in the district. Many of these structures have previously been mapped from both surface exposures and drill intercepts; and the Bellhaven team is focused on their importance in controlling mineralization.
The survey crew arrived on site November 17, and began conducting reconnaissance flights a few days later. They are currently flying the survey as cloud cover permits. It is expected that a total of 6 to 8 days of favorable conditions is needed to complete data collection, so the survey should be completed before the end of December.
La Mina is a resource stage porphyry gold-copper project located in the Middle Cauca volcano-plutonic belt in the Department of Antioquia about 45 km southwest of Medellin. The Middle Cauca belt is known to host large porphyry gold deposits such as AngloGold’s La Colosa Deposit (24 Moz Au) and Sunward Resources’ Titiribi Project (11 Moz Au).
The La Mina concession includes almost 2,000 hectares. A number of anomalous features are evident from the initial airborne magnetic survey, completed by AngloGold. As surface sampling and drilling progressed, a number of multi-faceted targets emerged. Through the first half of 2012, a total of four known mineralized porphyry systems have been identified; two of these deposits are host to NI 43-101 compliant inferred mineral resources. The two remaining known porphyries will be the focus of future drilling, meant to advance these prospects to the resource stage as well. The exploration pipeline at La Mina includes a number of other targets that, based on geology, geochemistry and geophysics, have characteristics similar to porphyry or porphyry related deposits. There are at least 7 of these discrete targets undergoing additional work, but they have not yet been drilled. The figure below shows total magnetic intensity (reduced to pole) from an airborne magnetics survey. Many of the targets are identified on this map; and more detailed information is available below.
South American Silver Corp. announces the results of a 5 hole diamond drilling program and the interpretation of the ZTEM Conductivity and Magnetic geophysical surveys at the Escalones copper-gold project, approximately 100 km southeast of Santiago, Chile and 35 km east of El Teniente, the world’s largest underground copper mine. Escalones, as previously announced and supported by a NI 43-101 technical report, contains a defined Inferred Resource of 420 million tonnes of mineralized material containing 3.8 billion lbs of copper, 56.9 million lbs of molybdenum, 610,000 ozs of gold and 16.8 million ozs of silver using a 0.2% Cu Equivalent cut-off grade (see December 19, 2011 News Release). The detailed NI 43-101 Technical Report is available on SEDAR under the Company’s profile and on the Company’s website at www.soamsilver.com.
The Escalones property lies within the well-known central Chilean porphyry copper belt that runs north-south through Chile in the central Andes Mountains. It is located approximately 100 km southeast of Santiago and 35 kilometers due east of El Teniente, the world’s largest underground copper mine. The project has excellent infrastructure including road access and a gas pipeline that crosses the 70 square kilometer property.
The Escalones project hosts a four-square-kilometer area of hydrothermal alteration with coincident geophysical anomalies that has demonstrated significant grades of copper, gold and silver in replacement-style “skarn” mineralization hosted in limestones and in porphyry related mineralization.
Diamond drill hole ES-35, located 300 metres E of ES-24, intersected 71 metres of near surface, oxide copper mineralization averaging 0.64% copper equivalent (“CuEq”). This near surface mineralization correlates with a ZTEM conductivity anomaly which is approximately 500 metres wide and at least one km long. Drill testing, starting when the snow clears in November, will further test this target. ZTEM is a geophysical tool that helps to identify mineralized areas that are conductive.
Diamond drill hole ES-35 also intersected high grade skarn mineralization at 456 metres intercepting 4.5 metres of copper mineralization averaging 4.32% CuEq within a 9.25 metres zone averaging 2.39% CuEq. A copper skarn is a carbonate rock that has been “cooked” and mineralized by the heat and fluids from nearby copper bearing intrusions. Examples of copper porphyry plus skarn deposits include the well-known Bingham Canyon Mine in Utah and the Twin Buttes Mine in Arizona.
The skarn at Escalones has now been traced by drilling approximately 1.7 km horizontally and 1.1 km vertically. A large magnetic anomaly is associated with much of the known skarn mineralization and this anomaly extends several hundred meters further to the north of the drilled area, at least 500 meters to the south and approximately 500 metres further east. The anomaly also extends to a depth of several km, many hundreds of metres below the level of current drilling.
Ralph Fitch, Executive Chairman, stated “This is the first time we have located a good thickness of near surface copper oxide mineralization at Escalones. The importance of this type of mineralization is that it is often the least expensive type of copper to recover because it is typically heap leachable. If future drilling shows that this zone is extensive it will be an important new body of mineralization that is not in the present resource. This new zone combined with that found on the west side of the property in holes ESC-26 (email@example.com% copper) and ESC-28 (firstname.lastname@example.org% copper) represents an important part of the mineralized system found to date at Escalones because of its likely low cost leachability. Also, the deep skarn intercept is important, both because of its grade and also because it demonstrates the huge column of copper mineralization present at Escalones which extends from surface to depths of greater than one kilometer. Our upcoming drill program will start to convert this vast column of mineralization into a resource.”
Upcoming Drilling Campaign
Up to 30 holes are planned to confirm and expand the resource in the 3 categories reported previously, oxide/sulphide, skarn and porphyry. The results from this drilling will be combined with earlier results and an updated resource will be developed and reported in compliance with NI 43-101.
The true thickness of the intercepts reported is not known at this time.
Magnetic susceptibility anomalies are only an indication of the presence of the skarn mineralization and the reader should not assume that “ore grade” mineralization will be intersected.
ZTEM conductivity anomalies are only an indication of the presence of mineralization and the reader should not assume that “ore grade” mineralization will be intersected.
Samples were analyzed by Andes Analytical Assay Laboratory located in Santiago, Chile. Gold was analyzed using fire assay and the AA (Atomic Absorption) method while silver, copper, gallium, indium, molybdenum and 38 additional elements were analyzed by ICP AES HF43 method with a four-acid digestion. The copper equivalent has been calculated using the following prices: copper $3.50/lb, gold $1,600/troy oz, silver $30.00/troy oz, molybdenum $11.00/lb, lead $0.90/lb and Zinc $0.90/lb. Values have not been adjusted for metallurgical recoveries.
Eagle Plains/Providence Identify 3 High-Priority Drill Targets from 2011 Airborne EM Geophysical Surveys
Eagle Plains Resources Ltd. and Providence Resources Corp. announces receipt of results from airborne geophysical field surveys carried out over their Iron Range JV project located near Creston British Columbia. During October-November 2011, Geotech Ltd. carried out VTEM time-domain EM and ZTEM AFMAG surveys over parts of the Iron Range Project. The results have subsequently been processed and interpreted by Condor Consulting, Inc. of Lakewood Colorado.
|•||440 line-km of airborne geophysical data has been collected over the Property area during 2011.|
|•||3 high-priority VTEM electromagnetic geophysical anomalies have been delineated in the Row target area, and are coincident with a 5km-long arsenic, zinc and lead soil geochemical anomaly.|
|•||The ZTEM survey successfully identified the Iron Range Fault as well as a northeast-trending fault similar in orientation to the gold-bearing faults at the Talon Zone.|
“Geophysical data collected on the Iron Range Project has produced three high priority EM conductors that coincide with lead, zinc and arsenic geochemical anomalies on the Row Target Area.” Stated Providence Resources Corp.’s President and CEO Vince Sorace. “The combined results from the geophysical surveys have fine-tuned the Iron Range geological model and increased our confidence in the Row Target area which will be drill-tested upon receipt of applicable permits, which are expected by Q2, 2012.”
Geophysical Survey Results
VTEM time domain-EM
A total of 7 anomalies were defined from the VTEM survey; seehttp://www.eagleplains.com/projects/bc/ironrange/documents/vtem_2011geophysicsmap.pdf Anomalies 1-3 represent high-priority EM anomalies and are located within and immediately adjacent to a ~5 kilometer-long lead-zinc-arsenic soil anomaly situated in prospective middle Aldridge Formation sedimentary rocks. These three anomalies may be an indication of subsurface Sullivan style lead-zinc-silver mineralization and will be drill tested in Spring, 2012. Anomalies 4 to 7 represent secondary priority targets and are likely related to the subsurface geology. Anomaly 4 is a broad, low level conductor associated with a magnetic contact and is interpreted to represent a near-surface bedrock anomaly or conductive overburden. Anomaly 5 is a formational anomaly defined by coincident EM and magnetic anomalies which correspond to the location of a sliver of upper Aldridge Formation sedimentary rocks. Anomaly 6 is a broad, northeast trending conductive zone associated with a linear, northeast trending magnetic anomaly. Drilling done in this area indicates that the anomaly is related to graphite within the Aldridge Formation sedimentary rocks. Anomaly 7 is interpreted to be an artifact that is related to a power line that transects this portion of the VTEM survey.
ZTEM AFMAG Survey
The ZTEM orientation survey was conducted over the Canyon Target (Talon Zone) to determine whether this geophysical method would be capable of mapping bedrock geology based upon the known resistivity and magnetic susceptibility contrasts within the Aldridge sedimentary rocks; seehttp://www.eagleplains.com/projects/bc/ironrange/documents/ztem_2011geophysicsmap.pdf The survey successfully identified the Iron Range Fault as well as a northeast-trending fault similar in orientation to the gold-bearing faults at the Talon Zone. In addition, the survey identified the broad conductive zone also detected by the VTEM survey. This information is useful in better understanding the subsurface geology of the Iron Range area and how known target areas relate to major rock units and structures.
Ongoing work by Eagle Plains Resources Ltd. is focused on exploring the potential of the Iron Range fault zone and surrounding area as a conduit and host for both sedimentary exhalative (SEDEX) Ag-Pb-Zn mineralization and Iron-oxide-Cu-Au (IOCG) mineralization.
2012 Exploration Program
The Company intends to execute a full exploration program beginning in March, 2012 (subject to receipt of permits) with the objective of systematically evaluating all existing exploration data, utilizing newly acquired geophysical data, field evaluating all resulting anomalies and ultimately drill testing the highest priority targets.
|•||Geophysical gravity survey – it is anticipated that results from this work will be available in March, 2012.|
|•||Winter drilling (Phase I) of high-priority geophysical and geochemical anomalies. High priority targets have been identified during the evaluation of historical geochemistry, 2011 soil geochemical surveys, and 2011 airborne geophysical data. Additional targets are anticipated.|
|•||Field work will be completed in summer 2012 with the objective of bringing remaining targets to the drill testing stage for Phase II drilling in late 2012.|
BonTerra Resources Inc. Fugro Airborne Surveys has commenced an aeroelectromagnetic survey over the entire Symphony Property (the “Property”). The Property is situated in the Omineca mining division approximately 29 kilometres southwest of Houston, British Columbia. BonTerra recently staked additional claims to consolidate its land position situated in between the Silver Queen Mine to the south and the Silver Streak property to the north.
Directly bordering the Property to the south is the past producing Silver Queen Mine. Historical ore grades are 8.72 opt (299 grams / tonne) silver, 0.18 opt (6.17 g/t) gold, 6.73% zinc, 1.16% lead, and 0.47% copper.
The Silver Queen property is currently being advanced by New Nadina Explorations. New Nadina has intersected silver, gold and base metal mineralization on the property. They have completed an aeromagnetic and ZTEM survey, a titan geophysical survey and diamond drilling. Drilling revealed grades of up to 493.5 g/t silver, 5.06 g/t gold, 13.5% zinc, 6% lead and 2.88% copper. The mineralized trend has a general southeast to northwest trend, the direction towards which the Property is situated.
General Location Map:
The Silver Streak property is situated to the north of the Property. Trenching on the Silver Streak identified significant mineralization which included 1.99% Cu and 338 g/t Ag over 33 meters. An inclined diamond drill hole was drilled underneath this trench in 1991. A zone grading 8.8 meters of 0.49% copper and 258 g/t silver, within 21.1 meters averaging 0.27% copper and 127 g/t silver was discovered. Another trench excavated in 2002 graded 0.26% copper and 1.91 g/t Ag over 16.7 meters. The mineralized zone is believed to have a NW-SE strike, the general direction of the Property.
This DIGHEM Electromagnetic survey with optional Radiometrics will total 308 line kilometres of readings. DIGHEM records electromagnetic data which can be interpreted to show changes in bedrock geology to great depth. The system uses multiple frequency electromagnetic fields to measure and map electrical conductivity in three dimensions. The DIGHEM EM system provides the interpretation benefits that can only be realized by a system employing both horizontal coplanar and vertical coaxial transmitter-receiver coil-pairs. BonTerra has selected Fugro’s optional Radiometrics application for an effective geological mapping solution as part of this mineral exploration program. The Company plans on using this survey to identify additional targets of interest on the property in its evaluation for silver and base metal mineralization potential on the Property.
JNR Resources Inc. reports that it is continuing to develop 3D exploration models to target new uranium deposits on its properties in the Athabasca Basin. JNR is a Saskatoon-based junior exploration company with one of the strongest technical teams in the uranium exploration industry. The Company is focused on uranium exploration in the Athabasca Basin of Saskatchewan and the Deer Lake Basin and Topsails igneous complex of west-central Newfoundland. These regions represent distinct uranium provinces that are characterized by significant uranium enrichment in many of the rock formations. JNR firmly believes that the best exploration approach is through actively exploring on the ground and drilling high-priority targets based on geology, geophysics, and geochemistry.
JNR is one of several uranium exploration companies that is using leading-edge exploration methods and tools in the Athabasca Basin to better understand mineralization processes/criteria for discovering new resources. These methods and tools include PIMA analyses, Pb isotope analyses, APS mineral analyses, 3D GOCAD modeling via a data- and/or knowledge-driven approach, numerical and/or geostatistical modeling, and high-resolution 2D/3D airborne and ground geophysical surveys, including high-resolution airborne gravity (FTG) and electromagnetic (ZTEM) surveys. In this respect, the Company is taking full advantage of the capabilities and expertise of its experienced, multi-disciplinary geological team.
Over the last 20 years, mineral exploration has evolved into a more rigorous quantitative science. A significant part of this exploration science includes a 3D GIS environment in which rich archives of diverse exploration data sets can be integrated, analyzed, and interpreted for the purpose of targeting new ore deposits. Building these 3D common earth models using the GOCAD environment/software appears to be a very efficient and effective tool for characterizing and exploiting the regional-, district- to mine-scale 3D common earth models of ore deposits and for determining the complex processes that produced the economic mineralization. For example, the complex spatial and geological relationships between lithological units, geological structures, geochemical data, alteration data, and geophysical data can be studied in detail. As well, a wealth of knowledge of ore-forming processes can be integrated into and queried by what-if scenarios within the geostatistical module of the GOCAD environment.
Results to date (2005 – present) from JNR’s 3D GOCAD models (e.g. eastern Athabasca, Way Lake, Yurchison Lake, Moore Lake, and Snowbird/South Dufferin) indicate that we have a much better understanding of the geological environments that we are exploring in and from this we can successfully pick new lithostructural/geochemical/geophysical drill targets in the search for new uranium resources. Ultimately, this will lead to finding new uranium deposits in less time.
In summary, when applied by experienced, multi-disciplinary exploration teams, this data- and/or knowledge-driven mineral potential modeling approach has great potential to enhance greenfield to brownfield mineral exploration activities within all uranium provinces. JNR will next put this to test by drilling some new discoveries along the eastern and southern margin of the Athabasca Basin (e.g. Snowbird/South Dufferin and Lazy Edward Bay).
Dave Billard, Vice President Exploration and Chief Operating Officer comments; “State-of-the-art, science-based exploration techniques are integral to our ongoing and planned exploration programs. For example, we have been able to define superior targets at shallow depths on our South Dufferin/Snowbird projects, which we plan to drill this summer. We believe these targets are lithostructurally related to the Centennial deposit (Cameco Corporation/Formation Metals Inc.) located approximately 20 km northeast and on strike of our properties. At Centennial, a 650-m long mineralized zone grading up to 8.78% U3O8 over 33.9 m has been outlined at approximately 800 m depth (Formation Metals news release May 30, 2011)”.
All technical information for the Company’s exploration projects is obtained and reported under a formal quality assurance and quality control program, details of which are presented on the Company’s website at: www.jnrresources.com/i/pdf/JNR-QAQC.pdf. A glossary of the technical terms included in this release can be found on the Company’s website at: www.jnrresources.com/s/Glossary.asp.
Canasil Resources Inc. announces that results from the recently completed ZTEM airborne geophysical surveys have outlined encouraging targets at the Company’s 100% owned Salamandra and Victoria projects in Durango State, Mexico. The ZTEM geophysical surveys at both projects have highlighted well developed structures which are possible locations for structurally controlled mineralization. These areas exhibit complex electromagnetic and magnetic signatures, which have the characteristics associated with intrusive sources, and are coincident with prospective local geology and geochemical surface anomalies defined by prior surface mapping, sampling and drill programs. These combined features have defined large targets for further exploration. A summary of the results at each project is included below for reference.
Bahman Yamini, President of Canasil, commented: “We are very pleased to see clearly defined and prominent geophysical signatures from the ZTEM surveys at Salamandra and Victoria projects. These provide significant high potential targets for follow up at these two large projects, both strategically located close to the city of Durango in a highly prospective mineralized belt in Durango and Zacatecas States, Mexico, hosting major silver and base metal mines. We look forward to further exploration programs to advance these projects.”
The recently completed ZTEM geophysical survey on the Salamandra Silver-Zinc project in Durango State, Mexico, has outlined a large complex area, measuring 2.5 km by 3.0 km, with low resistivity and flat magnetic response, interpreted to be an intrusive source. This is located east of and flanking the previously drilled Salamandra mineralized zone. The interpreted intrusive source is bounded by a north trending large regional fault on the east, and crosscut by several east–west fault zones. According to Frank Fritz, Canasil’s consulting geophysicist: “these are favourable locations for structurally controlled mineralization”.
Previous drilling on the western flank of the interpreted intrusive source intersected wide zones of calc-silicate skarn with disseminated silver-zinc mineralization, averaging 0.5% – 1.0% zinc and 5 g/t – 20 g/t silver, and high-grade silver-zinc sulphide filled structurally controlled breccia zones grading up to 20% zinc and 300 g/t silver.
The interpreted intrusive source outlined by the ZTEM survey is alluvium covered and has not been drill tested. There is excellent potential in this area to outline disseminated mantle replacement or high-grade breccia associated silver, zinc and copper mineralization related to acid quartz porphyry intrusives, similar to the large San Martin mine of Grupo Mexico, located 80 km to the southeast. Follow up surface mapping, geochemical and ground geophysical surveys are planned to further explore this high potential target.
The deep penetrating ZTEM geophysical survey on the Victoria project, located 25 km northeast of the Salamandra project, has outlined a target similar to that seen at Salamandra. The ZTEM survey has outlined an area of complex low resistivity and low magnetic response measuring 2.0 km by 2.5 km, indicating a large intrusive source at depth. Numerous zones with small workings of oxidized sulphides with anomalous lead, zinc, gold, arsenic and antimony are observed at surface associated with silicified and skarn altered sediments and small intrusives located immediately north, east and west of the outlined geophysical target. Several strong northeast and east-west trending shear structures are present similar to the Salamandra project target. The geophysical target outlined at the Victoria project has the potential to be a large massive sulphide skarn mantle mineralized system similar to the San Martin base metal mine of Grupo Mexico located 80 km to the southeast. A follow up program of geological mapping, rock and silt sampling and ground geophysics is planned.
The ZTEM airborne geophysical surveys were conducted by Geotech Ltd. The data was processed and provided by Geotech Ltd. The interpretations of the geophysical data were carried out by Frank Fritz, consulting geophysicist, and Gary Nordin, P. Geo., Director of Canasil and a qualified person under NI43-101. The surveys were flown with 10 km line length with a spacing of 200 metres. The Salamandra survey covered 617 line-kilometres over an area of approximately 120 square kilometers. The Victoria survey covered 680 line-kilometres over an area of approximately 130 square kilometers.
The Salamandra project is located 35 kilometres to the northeast of the city of Durango and covers 14,719 hectares, over 140 square kilometres. This large claim area is strategically located within the major silver-gold trend running through Durango and Zacatecas States, and is directly on trend with a number of important operating mines and recent discoveries. The project benefits from excellent access and infrastructure for mineral exploration and development. Prior geophysics and diamond drilling completed by Canasil has identified significant zinc-silver mineralization at Salamandra, with preliminary metallurgical tests showing high zinc and silver recoveries to clean concentrates. The project is located on the mineral-rich Fresnillo geologic trend, approximately 80 km northwest of the San Martin mine of Grupo Mexico, which is the largest underground zinc-copper-silver mining operation in Mexico, producing at approximately 6,000 tonnes per day.
The Victoria project covers a large prospective area of 60,000 hectares, 600 square kilometers, located 60 km northeast of the City of Durango and 25 km northeast of the Salamandra project. The project is centrally located on the same mineral rich trend, stretching from the northwest to the southeast through Durango and Zacatecas States, with excellent access and infrastructure. Initial reconnaissance, including geologic mapping and surface sampling by Canasil in the Victoria project area, has outlined prospective target zones, which were tested by the ZTEM survey. Located on a major mineralized trend, the very large project area is highly prospective for discovery of new mineralized systems.
Strait Gold Corporation announces that it has signed contracts for airborne geophysical surveys to be conducted over its Alicia copper-gold project in southern Peru.
Helicopter-borne ZTEM (a deep-penetrating, natural-field electromagnetic system), magnetic and radiometric surveys over the entire 26-sq.-km property are expected to begin within a month. Final results are expected before the end of June.
“Geophysics have been instrumental in identifying primary drill targets on many porphyry-type deposits around the world,” said Strait Gold President Jim Borland. “Combined with results from our reconnaissance drilling program completed earlier this year, these surveys will allow us to zero in on the best targets for our 2011 drilling campaign.”
The airborne surveys are being coordinated with a major mining company that is undertaking similar geophysical surveys in the same general area as the Company’s Alicia Project, resulting in an extremely cost-effective program for Strait Gold.
The Company has also retained Thomas V. Weis and Associates of Centennial, Colorado, to provide geophysical consulting services. Mr. Weis is the former Chief Geophysicist for Newmont Mining.
These airborne geophysical surveys are part of an aggressive exploration campaign planned for Alicia that includes stream sediment geochemistry over the entire property, detailed soil geochemistry over the central portion of the property and additional core drilling.
Strait Gold has an option to earn a 100% interest in the Alicia property situated in the Andahuaylas-Yauri copper belt approximately 500 km southeast of Lima. This belt hosts a number of important copper and copper-gold deposits including Las Bambas (about 40 km west of Alicia) and Antapaccay (about 80 km southeast of Alicia) in which Xstrata is investing an aggregate of US$5.7 billion to develop. The belt also includes the Haquira copper project (about 40 km west of Alicia), which was recently acquired by First Quantum Minerals, and the Constancia copper project (about 60 km east of Alicia), which was recently acquired by HudBay Mining.
The Alicia Project presents a prospective copper-gold-silver project in a favourable porphyry-skarn jurisdiction with potential for significant drill intercepts of moderate to high-grade copper along with significant precious-metal credits.
Past exploration has defined existing skarn zones at surface reasonably well with trench sampling at 60-70 m intervals within the main zone to the south, and at 100 m intervals within the main zone to the north. Highlights of this sampling returned up to 56 m at 1.9% Cu, 0.18 g/t Au and 12.7 g/t Ag from trench Iris 5, and 32 m at 2.8% Cu, 0.32 g/t Au and 14.7 g/t Ag from trench Iris 7. These results are historic in nature and shall not be relied upon. Infill trench sampling between mineralized skarn zones still needs to be performed.
The general geology of the main skarn prospects have been fairly well mapped at 1:5000 scale, however no property wide mapping appears to have been executed, nor any systematic sampling/mapping of the historic workings of high-grade Ag-Pb-Zn+/-Au-Cu veins located 2 km south of the skarn zones.
A ground magnetic and TEM geophysical survey was performed over the main skarn area. The results of the magnetic survey are very useful in mapping the intrusive body and indicate magnetic anomalies where no intrusive outcrop has been mapped but has been observed in the field by Strait geologists. The TEM survey produced a few wide, poorly defined anomalies at depth, some of which were drill tested with no significant results (AL-03, not assayed).
UC Resources Ltd. reports results of the drill program from the McFaulds Lake project area of the James Bay Lowlands (JBL) in the “Ring of Fire” and about airborne surveys on the property.
The 950 km airborne survey has been partially completed as equipment breakdown prevented the full survey. So 430 km were completed using the SHA three-axis, helicopter towed, magnetic gradiometer and VLF-EM system at a flight path separation of 100 meters. This is a very low flying close gradient survey and is expected to provide vivid magnetic detail.
The second airborne survey, a Fugro Airborne Survey, conducted a high-sensitivity aeromagnetic and Falcon™ Airborne Gravity Gradiometer (AGG) survey over the East and West claims of UC Resources Ltd. The production flights took place during January 2011 with the first production flight taking place on January 3rd and the final flight taking place on January 6th. The survey completed 5 production flights for a combined total of 1810 line kilometres of data acquired. Final reports of the airborne surveys to the Company are still pending.
ZTEM survey was flown on May, 2009.
Corvus Gold Inc. announces the discovery of two new gold targets at the Chisna Project in south-central Alaska. Surface exploration results from work conducted in 2010 has established the Golden Range target, where bedrock values of up to 50.4 g/t gold and soil values of up to 6.5 g/t gold have been found along a 9- kilometre-long zone of extensive gossanous iron carbonate alteration. A second target, known as Southwest Grubstake, has been discovered as a series of parallel quartz-dolomite-barite veins up to 2 metres wide defined over a 600-metre-long trend containing metal values from rock chip sampling of up to 46.5 g/t gold, 17.9 g/t silver, 1.3% lead and 0.19% zinc. These new targets will be further explored in 2011.
Golden Range Target
Large Continuous Gold Trend Defined By Bedrock and Soil Samples
The Golden Range target is located 5 km north of the Grubstake porphyry system discovered in the fall of 2010. A largely continuous gold anomaly has been defined by over 300 rock and grab samples taken across a 9 km by 2 km area of intense alteration. Reconnaissance sampling took place mostly along topographic crests, where sampled material is inferred to be approximately in place. All rock samples taken over the target area average 0.6 g/t gold, with 29 of 151 samples returning over 100 ppb (0.10 g/t) gold, and having a high value of 50.4 g/t gold. Samples returning over 100 ppb gold are present across the entire 9 km strike length of the Golden Range target.
Out of 176 soil samples taken across the same area, 71 samples returned greater than 100 ppb (0.10 g/t) gold with an average of 0.23 g/t gold and a high value of 6.53 g/t gold. Of the balance, 42 samples returned results between 0.05 g/t and 0.1 g/t gold and the remaining 63 samples returned results between 0.003 g/t to 0.48 g/t gold. This extensively mineralized gold zone occurs within a highly gossanous, iron-carbonate altered sequence of volcanic rocks and follows a strong northwest-to-southeast trending structural zone. The Golden Range target will be a priority during the 2011 Chisna exploration program, which will include detailed geological mapping, expansion of bedrock and soil sampling grids, and drill target definition.
Southwest Grubstake Target
Gold-Silver-Lead-Zinc Mineralized Vein System Discovered
New high-grade gold mineralization has been discovered along a series of en-echelon quartz-dolomite-barite veins on the southwest side of the existing Grubstake porphyry target. These polymetallic quartz veins have returned high gold values along with significant silver, lead and zinc values from veins ranging in width from 20 cm up to 2 metres. This vein swarm, which strikes NNE to NE within a NW to SW mineralized trend, has been delineated over a strike length in excess of 600 metres. A total of 19 rock samples derived from in-place quartz-dolomite-barite boulder trains and outcrops returned an average of 7.38 g/t gold, 8.82 g/t silver, 0.91% lead and 0.16% zinc, with highs of 46.5 g/t gold, 29.8 g/t silver, 4.22% lead and 1.22% zinc.
Mapping of vein lengths and density, and determination of the relationship between this veined mineralization and the adjacent Grubstake copper-gold porphyry system, will be a primary focus of 2011 exploration in advance of drilling.
Final 2010 POW and Grubstake Drill Results
In 2010, the Chisna project was advanced with the completion of airborne geophysics (6700 line kilometres of ZTEM) and extensive ground geophysics (100 line kilometres of 3D induced polarization) together with surface prospecting and drilling. This work has defined over a dozen priority targets of which only two, POW and Grubstake, were initially tested with drilling.
Results have been returned from the final POW target drill hole (PW-10-02) which was designed to cut down across the north-dipping copper-gold mineralization intersected in PW-10-01 and PW-10-03, previously reported on September 30, 2010. The hole was lost prematurely in a fault zone prior to intersecting the previously defined copper-gold mineralized zone. As such, the down dip continuity and tenor of the POW mineralization has yet to be tested and will be a target of exploration in 2011.
Results have also been returned from four reconnaissance diamond drill holes at the Grubstake target. Drill holes GS-10-02, GS-10-04, GS-10-05 and GS-10-06 all encountered pyritic porphyry-related alteration but did not intersect significant mineralized intervals. Geological mapping and interpretation of geophysical and drill data will continue on the Grubstake porphyry target to define future drill targets.
While a porphyry-style copper-gold mineralized system has been discovered at Grubstake, exploration in 2011 will mainly focus on the large gold-bearing systems which have been identified at the new Golden Range and Southwest Grubstake targets as well as the exiting POW target.
About the Chisna Project
The Chisna Project is focused on a new and emerging Alaskan copper-gold porphyry belt of deposits with copper and gold mineralization associated with mid-Cretaceous intrusions of similar age to the Pebble deposit to the west and Orange Hill deposit to the east.
Corvus and its predecessor-in-title, International Tower Hill Mines Ltd., began exploration on the project in 2006 and discovered the Grubstake porphyry copper system in 2007. Beginning in 2010, the Chisna project is being operated as a joint venture between Raven Gold Alaska Inc. (a subsidiary of Corvus) and Ocean Park Alaska Corp. (a subsidiary of Ocean Park Ventures Corp.), with Ocean Park earning 51% by contributing US$20 million in exploration expenditures over a 5 year period, thereby providing Corvus with a no-cost assessment of this belt. Ocean Park may earn an additional 19% by producing a bankable feasibility that delineates a mining project on the Chisna property that produces at least 300,000 gold equivalent ounces per year. Raven Gold has been designated as operator of the joint venture through 2011.
Athabasca Uranium Inc. announces the commencement of its multiphase exploration program for the Company’s McGregor Lake and Webb River uranium projects, located on the southeastern margin of the Athabasca Basin, Saskatchewan. The Company is also pleased to provide an update on its current suite of properties.
Phase One exploration, already underway, consists of a 2,740 kilometer heli-borne Z-TEM (Z-Axis Tipper EM) survey – a leading edge solution, particularly efficient at identifying discrete vertical conductive anomalies at depth. Conductive anomalies existing within magnetic discontinuities are key exploration indicators for altered sandstones and mineralized zones. In the Athabasca Basin, the vast majority of uranium mines and exploration deposits – including Denison’s Wheeler River Project, Fission’s Waterbury Lake Project, Hathor’s Roughrider Zone and JNR/Denison’s Moore Lake Project – are associated with subsurface graphitic conductors.
Results from the Z-TEM survey will be used to further refine conductive anomalies already identified at McGregor Lake and Webb River through previous ground and airborne surveys. Subject to the results, Athabasca will proceed with Phase Two Magnetoteulleric (MT) ground surveys to further identify and refine targets. High priority targets should then be available for Phase Three testing by diamond drilling. Athabasca will also employ 2D seismic surveys, utilized by Hathor at Roughrider and JNR/Denison at Moore Lake, to increase the likelihood of drilling success.
Gil Schneider, Athabasca Uranium’s president was quoted as saying: “Given the current bull market and positive outlook for uranium world-wide, this is a very exciting time to be exploring in the world’s richest uranium region.”
Geotech’s ZTEM system is an innovative airborne EM system which uses the natural or passive fields of the earth as the source of transmitted energy. The earth and ionosphere, both conductive, act as a waveguide to “transmit” the source energy great distances. Due to the manner in which they propagate, these natural fields are planar and horizontal. Any vertical field is caused by conductivity contrasts in the earth. The vertical EM field is referenced to the horizontal EM field as measured by a set of horizontal base station coils. The proprietary receiver design using the advantages of modern digital electronics and signal processing delivers exceptionally low-noise levels.
The 18,699ha McGregor Lake Project adjoins Denison/JNR’s Moore Lake Deposit (Maverick Zone), where significant uranium mineralization has been identified through multiple diamond drill programs. The unconformity related uranium mineralization in the Maverick Main zone has now been intersected over a minimum strike length of 350m. In 2005, Denison/JNR reported intersecting “classic unconformity-style mineralization, best exemplified by holes ML-61, ML-54 and ML-55, where respective intervals of 4.03% eU3O8/10 m (incl. 1.4 m @ 20% eU3O8), 3.5% U3O8/5.0 m and 5.14% U3O8/6.2 m were obtained. In ML-29, returning 1.61% eU3O8/7.5 m, an 0.5 m intersection graded 7.91% U3O8, 3.65% Ni, 2.8% As, 1.6% Cu, 0.9% Co, 0.35% REE and 5.3g/t Ag, confirming the polymetallic nature of the mineralization. Together with the newly discovered 527 and 525 zones, mineralization occurs over a 1.7-kilometre length of the minimum 6.5-kilometre long Maverick structural corridor. Over 50% of this corridor has yet to be drill tested.
International PBX Ventures Ltd. announces that Geotech Ltd. has completed its helicopter-borne ZTEM and magnetic surveys on the Company’s Copaquire and Huatacondo copper-molybdenum projects, located in northern Chile.
The airborne geophysical data will be analyzed to aid in the selection of drill targets for the Company’s previously announced drill program, which will commence in February, 2011 as well as for the selection of further exploration targets on unexplored areas of the property.
The airborne survey was conducted over known areas of copper and molybdenum mineralization (Sulfato and Cerro Moly) and the particular signature of these mineralized zones will be useful in identifying similar signatures in other areas in the Copaquire and Huatacondo properties.
The survey was also flown over the recently completed Titan deep penetration IP survey area, which will be the initial focus of the upcoming drill program. Comparative studies between the two geophysical surveys and subsequent drill results will be conducted in order to prioritize generated airborne survey targets over the entire property.
George Sookochoff, President & CEO of PBX, said, “We believe that this comprehensive and systematic airborne survey is an excellent tool not only to qualify new drill targets but also to get an overlook of the entire property. The Company expects to receive the results from Geotech Ltd. by the end of the month.”
The ZTEM system is one of the leading airborne geophysical systems in use today and is particularly suited to identifying large conductive ore bodies. The ZTEM system is renowned for its deep penetration, high spatial resolution and ability to detect and differentiate weak electro-magnetic anomalies at depths up to 1,500 metres.
The Copaquire porphyry includes three zones: Sulfato North, South and Cerro Moly and covers an area of about 7 square kilometres and encompasses potassic, phyllic, argillic and propylitic phases of alteration and as such possesses all the alteration characteristics ascribed to typical calc-alkaline porphyry copper systems. The porphyry has a leached cap and secondary chalcocite blanket, more typical of Andean porphyry systems like the nearby Collahuasi deposit which is exposed in the Sulfato Zone north of the Cerro Moly ridge.
Most exploration drilling to date has concentrated within a molybdenum stockwork system at the Cerro Moly Zone over an area of approximately 48 hectares. This zone remains open at depth and along the SW-NE long axis of the mineralized trend.
The Cerro Moly Zone is related to the emplacement of a distinct and younger mineralization event (Molybdenum-Rhenium stockwork) within an earlier larger porphyry copper system which hosts mostly copper mineralization.
Millrock Resources Inc. announces that it has begun a second round of drilling at its Galiuro porphyry copper-gold property in southeastern Arizona. The property is the subject of an earn-in agreement with Vale Exploration Canada Inc. (“VEC”), a wholly-owned subsidiary of Vale S.A. (“VALE”). VEC is funding work on the property with Millrock operating exploration operations. A program of approximately 4,000 m in four holes is planned.
The target at the Galiuro property is a large porphyry copper +/- gold deposit hidden beneath alluvium and Tertiary volcanic cover. The property is situated at the intersection of the Resolution and San Manuel / Kalamazoo porphyry copper trends. Because of the Tertiary volcanic cover, little exploration work has been previously done by other companies. Through careful geological mapping in combination with airborne magnetic and ZTEM geophysical surveys, Millrock has identified numerous targets that may represent porphyry deposits.
Drilling by Millrock and VEC in spring 2010 resulted in the discovery of porphyry copper mineralization and alteration in Cretaceous – aged rocks hidden beneath Tertiary volcanic cover rocks. The current drilling program will further test these targets as well as others in the area. Two of the holes will test the Fourmile target. This circular magnetic feature is ringed by a strong conductive zone as identified by a ZTEM airborne geophysical survey. Intense argillic alteration is known from rock exposures and prior drilling on the west side of the structure.
VEC has the option to earn a 60% interest in the project through exploration expenditures totaling US$3.5 million and payments totaling US$850,000. The earn-in agreement is in its second year, and VEC has expended approximately US$1.5 million on the property to date. VEC may earn an additional 10% interest, for a total of 70%, by funding a feasibility study.