Archive for category Airborne

In the news – Geotech technologies in Kazakhstan and Russia

Posted by on Tuesday, 2 December, 2014
FacebookTwitterGoogle+Share

In the National TV News (Kazakhstan)

 

In the local (Yakutia) Russian TV news:


Geology For Investors about an airborne EM technology for exploration

Posted by on Monday, 1 December, 2014

Hunting for Giants: An Introduction to ZTEM Surveys in Mineral Exploration
By: Kylie Williams in Exploration Methods

ZTEM

 

 

 

 

 

 

 

 

Overview

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.

History

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.

Further reading

The best place for information about ZTEM is the Geotech website, especially the ZTEM case study page

Several ZTEM case studies have also been published in peer-reviewed journals, for example:


New Multiple and Significant Nickel Sulphide Intersections at Maniitsoq – Greenland

Posted by on Tuesday, 4 November, 2014

North American Nickel Inc.  reports assay results for multiple and significant nickel sulphide intersections at the P-013 prospect, located seventeen kilometres south of the Imiak Hill Complex (IHC) on the Company’s 100% owned Maniitsoq Nickel – Copper – Cobalt and PGM project in southwest Greenland.

Highlights include:

  • MQ-14-066 (P-013): 5.85metres of 2.07% Ni and 0.12% Cu of semi-massive sulphides within a broader zone of 11.0 metres of 1.31% Ni and 0.15% Cu.
  • MQ-14-068 (P-013): 3.4 metres of 2.07% Ni and 0.34% Cu net-textured to semi-massive sulphides within a broader zone of 15.85 metres of 0.87% Ni and 0.27% Cu.

NAN President and Interim CEO, Mark Fedikow, commented: “Drilling at the P-013 prospect in 2014 was a follow-up to the initial discovery hole drilled in 2013, and has resulted in significant and multiple nickel sulphide intersections. These results not only confirm the prospectivity of P-013 but also the larger exploration potential of the central region of the Maniitsoq project. The results validate our regional exploration strategy and the excellent work being carried out by the exploration team. I look to further assay results pending from the 2014 program.”

Results for three regional drill holes and one IHC hole are reported below and provided in Tables 1 and 2 and Figures 1 and 2. Figures may be viewed using the link provided with this release.

REGIONAL

The P-013 area is located seventeen kilometres south of the Imiak Hill Complex, in the central portion of the Maniitsoq property, and comprises several helicopter-borne electromagnetic (VTEM) anomalies occurring over a distance of approximately 500 metres. The anomalies include the P-013 Centre, P-013 SE and P-013 NW targets (see Figure 1). In 2014, three holes totalling 739 metres were completed to test the P-013 targets.

P-013 Centre

Nickel sulphide mineralization intersected at this target was discovered by a combination of ground prospecting and drill testing of a VTEM anomaly buried beneath a large boulder field. In 2013, one hole (MQ-13-032) was drilled to test a 200m long northeast trending VTEM anomaly, and intersected a thick section of norite and leucogabbro containing several intervals of nickel sulphide mineralization (News Release November 21, 2013). The best intersection graded 0.44% Ni and 0.20% Cu over 6.51 metres including 2.35% Ni and 1.21% Cu over 0.73 metres. Borehole electromagnetic (BHEM) surveys detected moderate to high conductance off-hole anomalies associated with the mineralized intervals, suggesting the presence of stronger mineralization nearby.

In 2014, two holes (MQ-14-066 and MQ-14-068) totalling 597 metres were completed to follow-up the 2013 results. Both holes intersected mineralized norite as outlined in more detail below.

MQ-14-066 was drilled to test an off-hole BHEM geophysical anomaly detected from the discovery hole, MQ-13-032. MQ-14-066 was collared in orthogneiss and intersected leuconorite, norite and pyroxenite extending from 63.48 metres to the end of hole at 365 metres. A number of narrow intervals of net-textured to semi-massive sulphides were intersected between 94 and 150 metres returning values ranging from 1.55% to 2.23% Ni and 0.18% to 0.70% Cu (see Table 1). The main zone of mineralization was intersected from 157.0 to 168.0 metres and consisted of 11.0 metres of norite-hosted bleb, net-textured and semi-massive sulphides grading 1.31% Ni and 0.15% Cu, including a semi-massive sulphide interval grading 2.07% Ni and 0.12% Cu over 5.85 metres from 158.43 to 164.28 metres. A second wide zone of similar mineralization was intersected from 201.20 to 223.94 metres and graded 0.50% Ni and 0.15% Cu over 22.74 metres including 1.79% Ni and 0.31% Ni over 2.14 metres from 203.35 to 205.49 metres.

MQ-14-068 was drilled approximately 45 metres up-dip of MQ-14-066 and intersected 15.85 metres of norite-hosted bleb and net-textured sulphides grading 0.87% Ni and 0.27% Cu from 126.7 to 142.55 metres. Included within this zone was a higher grade interval of net textured to semi-massive sulphides which graded 2.07% Ni and 0.34% Cu over 3.4 metres from 130.85 to 134.25 metres. These intersections correlate well with the main sulphide zone intersected in hole MQ-14-066.

Borehole EM surveys indicate that the mineralization is correlated with a conductive trend interpreted to strike northeast-southwest, dipping steeply northwest and plunging steeply west. Additional drilling will be required to determine the extents of the P-013 mineralization, and more work will be planned for this area in 2015.

P-013 SE

MQ-14-069 was drilled to test a second VTEM anomaly (P-013 SE) located approximately 250 metres southeast of the above P-013 Centre target. A previous attempt was made in 2013 to test this target with hole MQ-13-034. Both holes intersected intervals of norite but failed to intersect the conductor. Re-modeling of the VTEM data, as well as modeling of the borehole EM survey data from hole MQ-14-069, indicates the target lies to the west of both holes. Target P-013 SE remains a high priority drill target based on positive results obtained at the nearby P-013 Centre target.

NN-VTEM

- See more at: http://www.northamericannickel.com/news/news-details/2014/North-American-Nickel-Reports-New-Multiple-and-Significant-Nickel-Sulphide-Intersections-at-Maniitsoq/default.aspx#sthash.qftRtJBB.dpuf


Airborne geophysics for La India Gold Mining District in Nicaragua

Posted by on Tuesday, 30 September, 2014

Condor Gold plc , a gold exploration company focused on delineating a large commercial reserve on its 100%-owned La India Project in Nicaragua, which hosts a CIM compliant Mineral Resource of 2.4 Million oz gold at 4.6g/t, is pleased to announce the results of a helicopter borne magnetic and radiometric survey on the entire 280 sq km La India Project.

Highlights

  • The 3,351 line kilometer helicopter borne geophysics survey resulted in high quality datasets suited for interpretation on both regional and project scales.
  • The radiometric data sets can be used as a direct tool to map vein presence.
  • The magnetics can be used as an indirect tool for target delineation by the interpretation of zones of magnetite destruction. In addition, the magnetics are of sufficient detail to make a realistic structural interpretation. 
  • The recognition of the geophysical properties associated with the known veins and extrapolation of those characteristics into other less well-mapped areas demonstrates that only a small part of La India Project has been tested by drilling.
  • Two prospective regions in the north and northeast of La India Project have been identified as having similar geophysical signatures to the main Vein Sets.

Mark Child, Chairman and CEO commented:

“The 3,351 line kilometer helicopter-borne geophysics survey covering the entire 280 sq km La India Project has confirmed that there remains considerable exploration upside for La India Project. The radiometric survey provides a powerful regional mapping tool. In particular, the potassium response has a strong correlation with areas of known gold veining. The magnetic survey helps identify fault zones, which normally hold gold mineralisation in the District. Together, the radiometric and magnetic surveys provide a targeting tool for future exploration whereby three areas have been highlighted that have a prospective radiometric and magnetic signature but relatively little drilling when correlated to the areas containing the existing gold mineral resources.”

New Sense Geophysics Limited completed a 3,521 line-kilometer helicopter-borne magnetics and radiometrics survey on behalf of the Company in May 2013. The main survey was flown on 100m spaced lines with an azimuth of 030/210 degrees with tie-lines flown at right angles to the main survey lines on 1000m line-spacing (Figure 1: http://media3.marketwire.com/docs/condor-0813-fig1.pdf). A terrain clearance of 30m was specified and largely achieved for the survey. The survey produced high quality datasets well suited for interpretation on both regional and project scales.

The heliborne geophysics data has been processed and interpreted by consultant geophysicist Buks Lubbe (BSc. Hons. Exploration Geophysics) and detailed in a report to the Company. The key points in the report are summarised here.

Radiometric Survey

The radiometric responses are robust and well-defined in the survey area. Although there are some obvious topographic-radiometric relationships, especially in the eastern portion of the survey and locally in larger drainages, the majority of the radiometric response appears to be related to the underlying geology.

The potassium response, as well as the thorium to potassium ratio, has a strong correlation with areas of known veining in the core of the La India Project. Maps of these data sets clearly show other areas within the Project area with a similar high potassium and low thorium:potassium ratio that may host undiscovered vein zones (Figure 2: http://media3.marketwire.com/docs/condor-0813-fig2.pdf).

The radiometric data also provides a powerful geological mapping tool. Ternary images, which combine the three main radiometric responses, potassium, uranium and thorium to show areas of common and exclusive radiometric signatures, are reasonably robust and can be used to define lithological units through correlation with known outcrops.

Magnetic Survey

The magnetic data has been transformed using industry-standard reduction to the pole algorithm and then processed to highlight various geological features. The traditional reduced to the pole dataset reflects the geology nearer to the surface. This, together with a dataset that has been processed to generate the first vertical derivative, which reflects changes in the magnetic signature, is very useful in mapping local geological fabrics. The displacement and/or abrupt termination of these fabrics typically maps fault zones. Deeper geological features which have longer wavelength magnetic signatures can be highlighted by using a 100m upward continued directional filter.

The magnetic data shows a general WNW to NW-striking fabric over much of the survey area (Figure 3:http://media3.marketwire.com/docs/condor-0813-fig3.pdf). The known veins are mostly parallel to these trends and are often associated with zones of disrupted magnetic signature that reflects the localised destruction of magnetite. Similar structures can be traced through less well explored parts of the Project area. The identification of disrupted signatures on these structures provides a targeting tool for future exploration.

Lithological mapping is aided by the magnetic intensity data. For example a magnetic high on the footwall side of the America vein can be correlated with a basaltic andesite unit.

A series of alternating NW-striking magnetic highs and lows evident when the 100m upward continued directional filter is applied suggests that the basement is made up from a series of parallel and sub-parallel horst/graben features. Sigmoidal patterns are possibly the result of the slight angles between the grabens, or alternatively, an indication of the presence of extensional faults.

Conclusion

Radiometric and magnetic data can be correlated to the known gold mineralized veins. The mineralized veins are associated with elevated potassium, especially where elevated relative to thorium, and with destruction of the magnetic signature, effects attributable to potassic alteration and magnetite destruction respectively by the epithermal fluids that deposited the gold mineralized veins. The identification of a similar geophysical signature elsewhere in the Project area can be used to target exploration for both the discovery of new gold mineralization and the prioritization of the many existing gold anomalies recognized in the existing rock chip sampling database.

Structural and lithological information gained from the geophysics contributes to a better understanding of the mineral deposit system at La India, which will help guide exploration strategy and targeting.

Three broad target areas have already been identified based on the geophysics. The main target is the central portion of the survey area containing the majority of known veins and hosting the current resource. See Figure 4 below. This clearly looks to be the most prospective part of the area surveyed. Here the strong and robust potassium response and wealth of magnetic features that are associated with veins suggest potential for additional vein discoveries. The structural interpretation suggests that the main vein field is located within a regional NNW striking fault corridor. Only a small portion of this prospective area has been tested by drilling where a mineral resource of 2.3M oz gold has been defined.

Two further target areas have been identified to the north and northeast of the existing gold resource in Figure 4 (http://media3.marketwire.com/docs/condor-0813-fig4.pdf), which offer excellent exploration potential. In the area to the northeast multiple gold mineralised rock chip samples have been recorded but only followed up with trenching in one locality; the Andrea Vein that was trench sampled by Condor in 2009-2010, and only drilled in one locality; ten drill holes on the Cristallito-Tatescame Prospect which hosts an inferred mineral resource of 200kt at 5.3g/t gold for 34,000 oz gold. In the area to the north, a strike continuous linear potassium high anomaly is subparallel to the main north west trending veins to the south and may be an extension to the main zone. There has been no drilling in this area.

The next step is to conduct a more detailed interpretation of the geophysical dataset, integrating the data with satellite derived high resolution topographic models and geological outcrop mapping and drilling data to produce an updated geological map. Exploration targeting will look in particular for zones of truncated and disrupted magnetics that are associated with positive potassium signatures.


Airborne EM and ground IP geophysical anomalies – the new Significant Copper-Gold System in Panama

Posted by on Tuesday, 30 September, 2014

Pershimco Resources Inc. announces that the results of its recent exploration drilling on the Idaida target have confirmed a new copper-gold system. Importantly, this newly revealed system shows both near surface and deeper mineralized feeder structures analogous to the Company’s two main targets, La Pava and Quema Deposits, the latter of whose center is located 1.3 km north-west of Idaida.

HIGHLIGHTS OF THE IDAIDA DRILLING

  • Extends high-sulphidation alteration and mineralization to depth;
  • Intercepted an oxide gold zone and an underlying sulphide copper-gold zone;
  • Intercepted new high-sulphidation “feeder” zones at depth;
  • Both upper and lower ‘feeder” zones flank and dip towards the modeled airborne and ground IP geophysical targets.

Dual Reverse Circulation/Diamond drill holes (RC/DH), PRH13316/PDH135316 (’316′) and PRH13317/PDH135317 (’317′) are the deepest to date on the Cerro Quema project, and provide important information on the mineralization and alteration system at Idaida as well as other exploration targets within the concession. Both drill holes (’316 & 317′) intercepted sulphides commencing at 85 and 50 meters downhole respectively and both continued to show sulphides and alteration to their final depths. Intercepted “feeder” zone mineralization within both the upper and lower levels show similar intense alteration (acid leach – advanced argillic) and moderate to strong sulphide mineralization.

Of particular significance, the lower feeder structure intercepted by drill hole ’317′ which returned 58m @ 0.38%Cu was enveloped within a broader intercept of 95m @ 0.25%Cu. This intercept showed elevated sulphides (>6%) and hosted within an advanced argillic alteration zone containing pyrophyllite. The dominance of the advance argillic mineral pyrophyllite indicates a higher temperature setting typically found within the ‘root zones’ of high sulphidation systems.

These “feeder” structures are on the margins of and dip towards the airborne VTEM and ground IP chargeability geophysical anomalies.

Figure 1 below shows the drill hole location plan as well as the location of the IP Chargeability target. Furthermore, a short video demonstrating the location, size and geometry of the Idaida project’s IP chargeability anomaly is accessible at http://youtu.be/m8eXp0bsHkA.

During the first half of 2013, Pershimco completed important exploration activities on two new targets outside of the La Pava and Quema-Quemita deposits. This work included:

  • Idaida and Pelona were drill tested, returning significant copper and gold intercepts;
  • 7,195 meters of drilling (RC and diamond) completed;
  • 112.5 Line Kilometers of IP geophysics completed; and,
  • Commenced regional mapping and geochemical sampling program on additional exploration targets identified by previous airborne geophysics.

The Idaida drilling results are extremely exciting in terms of the significant grades and thicknesses of copper and gold mineralization intersected near surface as well as the discovery of additional feeder structures at depth. The exploration geophysics and geological modeling undertaken by the Pershimco Team is proving to be successful as more targets are being strategically identified and developed. As we have noted previously, this deliberate multi-staged approach continues to prove to be invaluable in building on the success our project,” said Alain Bureau, President and CEO of Pershimco.


Drilling Results of Anomalous Radioactivity and Conductors (Athabasca basin)

Posted by on Thursday, 25 September, 2014

 FISSION URANIUM CORP. announces the results of 21 of its 22 regional drill hole program at its PLS (Patterson Lake South) property in Canada’s Athabasca Basin. Four new holes have discovered anomalous radioactivity on three new conductors in the PL Corridor and Far East target areas of PLS. This follows exploration hole, PLS14-255 (see NR August 11, 2014), also drilled on the Far East target area, which hit radioactivity 17km from the main PLS discovery where high-grade mineralization has been outlined along a 2.24km strike length. The remaining 17 regional holes encountered encouraging geological features but did not intersect significant radioactivity.

Another Three Holes Encounter Anomalous Results on Far East of PLS Property

  • Significant anomalous radioactivity intersected by:
    • Hole PLS14-260 (104A EM conductor)
    • Holes PLS14-262 and PLS14-284 (105A EM conductor)
  • PLS14-262 and PLS14-284 are approximately 14m and 25m respectively from hole PLS14-255 (105A EM Conductor), which recently intersected anomalous radioactivity of up to 2532 cps.
  • Holes are located near the Fission 3.0/Brades Clearwater West project, approximately 17km south east of the main PLS discovery

One Exploration Hole Hits on PL Corridor of PLS Property

  • Anomalous radioactivity intersected by:
    • Hole PLS14-252 (1B EM Conductor) has intersected anomalous radioactivity on the PL Corridor,
  • Hole is located approximately 750m east from the main discovery

Ross McElroy, President, COO, and Chief Geologist for Fission, commented,

“The regional exploration program has been a great success and we have three very clear target areas prioritized for aggressive follow up: The PL Corridor, the Far East where we recently hit anomalous radioactivity in hole PLS14-255 and the Forrest Lake Areas. With over 105 separate conductors, we have felt for some time that the prospectively of PLS goes beyond the incredible discovery we have already made. These regional drill results confirm that belief.”

 

PLS is one of the most exciting uranium discoveries made to date in Canada’s prolific Athabasca Basin, which hosts the richest producing uranium mines in the world. The discovery is driven by a highly skilled technical team and successful entrepreneurial management. After a series of corporate transactions, Fission Uranium consolidated 100% ownership of the PLS Property, which comprises 17 claims totaling 31,039 ha located on the southwest margin of the Athabasca Basin. The property is accessible by all-weather Highway 955 which continues north through the area of the UEX-AREVA Shea Creek discoveries to the past producing Cluff Lake uranium mine.

The PLS discovery is a basement hosted unconformity uranium deposit, characterized by shallow, high-grade mineralization in five separate zones trending for approximately 2.24 km in length. From west to east, these zones are; R600W, R00E, R780E, R1155E and R1620E. Up to and including the drilling from the winter 2014 program, 163 delineation holes have defined mineralization over a strike length of 1155m in the R00E and R780E zones, with 158 holes intersecting mineralization, for a 97% success hit ratio. Mineralization has exhibited high grades over exceptionally wide thicknesses, which remain wide open.

 


Unlocking Australia’s hidden mineral potential with geophysics

Posted by on Friday, 1 August, 2014

Dr Richard Blewett:

“It is becoming increasingly difficult to discover near-surface mineral resources in Australia. New and innovative products and techniques are being developed as part of the UNCOVER Initiative to help attract mineral exploration investment that has the potential to lead to the discovery of new resources.”

One of the focus regions for the UNCOVER Initiative is the Thomson Orogen: “The Thomson Orogen is a large area that lies to the north and west of the Lachlan Orogen in New South Wales, South Australia, the Northern Territory and Queensland. Much of it is under the cover of younger sedimentary basins, with some up to several kilometres thick, and it is therefore a poorly understood element of Australia’s geology.

The southern Thomson Orogen is true ‘greenfields’ country. Although the mineral potential of the region is largely unknown, the northeastern Thomson Orogen (for example Thalanga, Charters Towers) and the similar-aged Lachlan Orogen to the south are well mineralised (for example Cadia, Northparkes, Lake Cowall Cobar). In order to attract exploration investment into the southern Thomson Orogen, and also to improve the geological understanding of the area, Geoscience Australia, the Geological Survey of Queensland and the Geological Survey of New South Wales have commenced a collaborative project to collect new (and synthesise existing) pre-competitive data.

One of the first steps in this collaboration is to acquire airborne and ground geophysical data including airborne electromagnetics (AEM), gravity and magnetotelluric (MT) data. Regional AEM data has now been collected to map cover thickness and assess the geology and prospectivity of the Southern Thomson Orogen across the New South Wales-Queensland border around Hungerford and Eulo. These data will be interpreted using existing borehole stratigraphic data and a new solid geology compilation of the region developed between Geoscience Australia, the Geological Survey of Queensland and the Geological Survey of New South Wales.

 

The Geotech VTEM FullWaveForm
airborne electromagnetic acquisition
system used in the Southern Thomson
Orogen airborne electromagnetics survey.
Image credit: Geotech Airborne Limited.

 

 

 Geoscience Australia is a leading promoter of AEM surveying for regional mapping of cover thickness, under-cover basement geology and sedimentary basin architecture. Geoscience Australia flew three regional AEM surveys during the 2006-11 Onshore Energy Security Program (OESP): Paterson (Western Australia, 2007-08); Pine Creek-Kombolgie (Northern Territory, 2009); and Frome (South Australia, 2010) [1]. The surveys were primarily designed to provide reliable, fit-for-purpose pre-competitive AEM data for mapping critical features of uranium mineral systems.

Results from these surveys have now produced a new understanding of the architecture of critical mineral system elements and mineral prospectivity for a wide range of commodities of these regions and includes details on the thickness and character of the regolith, sedimentary basins and buried basement terrains. The data have since been found suitable not just for uranium, but for mapping a range of other mineral systems including gold, silver, copper, lead, zinc and potash, as well as for under-cover geological mapping and groundwater resource estimation.

The survey data are now processed using the National Computational Infrastructure (NCI) facility at the Australian National University to produce GIS-ready interpretation products and GOCADTM objects suitable for 3D modelling.

A number of 3D models are being developed to interpret the near-surface under-cover geology of cratons and mobile zones, the unconformity surfaces between these and the overlying sedimentary basins, and the architecture of those basins. These models are constructed primarily from AEM data using stratigraphic borehole control and show how AEM data can be used to map the cross-over area between surface geological mapping, stratigraphic drilling and seismic reflection mapping. These models can be used by minerals explorers to more confidently explore in areas of shallow to moderate sedimentary basin cover by providing more accurate cover thickness and depth to target information. A 3D model of basement-cover relationships and depth of cover will be developed for the southern Thomson Orogen.”


Ground EM and gravity for a Ni-Cu-PGE project in Greenland

Posted by on Friday, 25 July, 2014

North American Nickel Inc. announces the completion of surface geophysical surveys and identification of electromagnetic and gravity anomalies at the Company’s 100% owned Maniitsoq nickel-copper-cobalt-PGM project in southwest Greenland.

Surface time domain electromagnetic (TDEM) and gravity surveys were initiated at the Maniitsoq project in mid-April and were completed in mid-June. The surveys were carried out by Crone Geophysics of Mississauga, Ontario and focused on two areas, the Imiak Hill Conduit Complex (IHCC) and Fossilik, where previous drilling intersected significant Ni-Cu-PGE mineralization (See Figure).

Preliminary TDEM results indicate the presence of EM anomalies correlating with both existing mineralization and also representing new geophysical targets. Preliminary gravity results indicate that gravity anomalies exist in both the Imiak and Fossilik areas and correlate with noritic intrusions identified from both surface mapping and drilling. Several of the known nickel-copper occurrences are empirically observed to occur at the margins of these gravity highs.

NAN President and Interim CEO, Mark Fedikow, commented: “The 2014 exploration program is well underway and completion of the surface geophysical surveys over the IHCC and Fossilik areas is an important component in our exploration strategy. The addition of gravity surveying this year represents a valuable new tool for exploring the Company’s large Maniitsoq property where noritic intrusions occur over a 75 km strike length. Identification and correlation of gravity highs with two of the known mineralized norite intrusions in the belt indicate that gravity will be very useful in mapping the subsurface extents of mafic and ultramafic intrusions and in helping to understand the distribution of related nickel-copper sulphide mineralization”.

TDEM surveying totaling 87 line km have been completed in the IHCC and Fossilik areas located in the central portion of the Maniitsoq property. Data interpretation and modeling are in progress and results are being used to target both follow-up drilling as well as define new targets for potential drill testing.

Gravity surveys were completed over the IHCC and, based on favorable results, an additional gravity survey was carried out over the Fossilik area. In each area, the surveys consisted of a core of gravity readings at 50m stations on 200m line intervals surrounded by more widely spaced readings typically on 500m centers. Gravity readings were taken at a total of 944 stations. The preceding comments are based on initial data modeling and inversions.

At the IHCC (see Figure 2), several gravity highs are observed to be coincident with, or flanking, the mapped and interpreted norite outcrops. Gravity inversion modeling shows one of the gravity highs to be coincident with the mineralized Spotty Hill norite intrusion. This gravity high extends south of the current Spotty drilling and also extends to the northwestward towards the Imiak North area. Another larger more complex double lobed gravity high lies in the immediate vicinity of the mineralized Imiak Hill norite intrusion. One lobe of this gravity high extends south of the Imiak Hill drilling and the other lobe lies to the NW.

GravityNAN

At the Fossilik area located 9 km southwest of the IHCC (see Figure 3); gravity surveying identified a large ~1.5 km x 2.5 km gravity high which is coincident with the Fossilik norite intrusion. Surface nickel occurrences and nickel mineralization intersected in historic drilling and past drilling by the Company are observed to lie at or near the southwestern and western margins of this gravity high.

Data interpretation and modeling are on-going but results to date indicate that gravity data will be a useful tool to aid in mapping the sub-surface extents of the target noritic intrusions, particularly as compared to the magnetic data where correlation of anomalies with norite intrusions is less consistent. Additional images of the gravity inversions may be viewed on the Company’s website.

- See more at: http://www.northamericannickel.com/news/news-details/2014/Surface-Electromagnetic-and-Gravity-Geophysical-Surveys-Completed-and-New-Anomalies-Identified-at-Maniitsoq-Nickel-Sulphide-Project-in-Greenland/default.aspx#sthash.fnhpBAK6.dpuf

To view the photo associated with this press release, please visit the following link: http://media3.marketwire.com/docs/958596a.pdf.


A set of geophysics for Iron Oxide Copper Gold deposit in Quebec

Posted by on Thursday, 17 July, 2014

Honey Badger Exploration Inc.  has completed the interpretation of the geophysical data over the Delhi Pacific copper showing on its Sagar Property. The coincident gravity, magnetic, electromagnetic (“EM”) and induced polarization (“IP”) anomaly associated with the Delhi showing are typical of those expected from an Iron Oxide Copper Gold (“IOCG”) deposit.

The IOCG model is further supported by the presence of a favourable structural setting for an IOCG deposit, namely the abundance of polymetallic showings (copper-gold-silver-cobalt) and the presence of diagnostically verified IOCG hydrothermal alteration.

At the Delhi Pacific showing, historical significant drilling intersections include 45.81 metres @ 0.51% copper and 10.7 metres @ 0.78% copper. While these intersections were not tested for silver, gold or cobalt, historic and recent grab samples* contain up to 1.8 grams per ton (“g/t”) gold, and up to 35 g/t silver.

*Grab samples are selective by nature and are unlikely to represent average grades of the deposit(s).

The selection of new drill targets is based on an interpretation of the IP/Resistivity, airborne magnetics, ground gravity and airborne EM data. In the winter of 2014 ClearView Geophysics Inc. completed a Surface Spectral IP survey over part of and extending east of the Delhi Pacific showing (Figure 1).

To view ‘Figure 1 – Surface Spectral Induced Polarization survey location lines’, please visit the following link:http://media3.marketwire.com/docs/honef10715.pdf

The interpretation indicates an anomaly associated with the historic drilling at Delhi that increases both in intensity and size east of these drill holes for more than 1.5 kilometres. The apparent resistivity data is presented in Figure 2 (red-purple indicates low resistivity and represents the target area):

Figure 2 – Resistivity Data at Delhi Pacific

The gravity data indicates that the southwest side of the magnetic high zone at Delhi Pacific coincides with a gravity low feature, whereas to the north is a gravity high. This indicates that the resistivity low/chargeability/electromagnetic target is located along a major structure that represents a favourable event for IOCG mineralization. The target area at Delhi covers more than 3 square kilometres: approximately 1.5 kilometres in strike length multiplied by an average width of 200 metres (Figure 3).

‘Figure 4 – Magnetic Inversion over Delhi Pacific’


Advanced airborne geophysics technologies for new industry development and innovations in Kazakhstan

Posted by on Tuesday, 8 July, 2014

2 July 2014 – Astana, Kazakhstan

The President of Kazakhstan and the Government took part in the  meeting-report of the Ministry of Industry and New Technologies in the new high tech building “Nazarbayev Cener” (project of famous British architect Norman Foster) in Astana.

Astana- Nazarbayev Center

 

 

 

 

 

 

 

 

 

 

 

 

 

(“Nazarbayev Center”,  Astana)

Geotech Ltd., a world leader of airborne geophysics had been presented to the government, Prime Minister and the President. “Kazgeology” as a part of the Ministry is going to work together with Geotech Ltd. for geophysical surveying of Kazakhstan territory and providing the airborne geophysical service for exploration and mining companies in Kazakhstan and other countries of Central Asia.

Geotech-PresidentKazakhstan

(Keith Fisk, Managing Director of Geotech with the President Nursultan Nazarbayev)

GT-Minister

 

 

 

 

 

 

 

 

 

 

 

 

 

(with the Minister of Industry)

GT-clients

 

 

 

 

 

 

 

 

 

 

 

 

 

(future surveys discussions with Rio Tinto and Iluka Resources)

GT-interview

(Keith Fisk, Managing Director of Geotech  interview to central TV channel)

 

 

 


Geophysical Survey helicopter in promotional filming at Elko Regional Airport

Posted by on Tuesday, 24 June, 2014

ELKOGeotech takes to the air to figure out what’s underground with its geophysical surveys.

On Monday, a AW-119 “Koala” helicopter and an 85-foot geophysical survey apparatus were at Elko Regional Airport to film promotional footage for Geotech. The film crew works for Cineplex, a company based in Canada.

Geotech specializes in airborne geophysical survey systems, according to Field Operations Manager Darren Tuck. The company’s clients are usually mineral exploration businesses that are interested in starting up a mine, and use the survey to find promising mineral deposits, including coal, silver, iron and copper.

Tuck said an apparatus carried by a helicopter will produce an electromagnetic pulse into the ground it flies over. Those pulses reflect off magnetic readers, and Geotech makes a map of the area after the process.

“It provides our client with a map of what the underlying layers of a structure looks like,” Tuck said.

Geotech is a global company based in Canada. Tuck said the company has worked for local mines, although he wouldn’t name any of the company’s clients in order to protect their confidentiality.

Tuck said the Elko airport was selected as the location to film Geotech’s equipment, known as Versatile Time Domain Electromagnetic surveying. Tuck said Geotech has more than 30 VTEMs. The apparatus comes in a variety of sizes.

For information, visit www.geotech.ca.


An exploration program on the Samaqua property (Quebec) with airborne and ground geophysics

Posted by on Thursday, 19 June, 2014

The property is located north of Girardville in the Saguenay-Lac-Saint-Jean region of Québec, Canada, close to the Crevier project.

Work will consist of a helicopter-borne geophysical survey and an induced polarization ground survey on a circular anomaly. MDN plans to carry out about 1,500 metres of drilling on the target once the geophysical surveys are complete. The goal of the exploration program is to confirm the presence of a carbonatite or an alkaline system with the potential to host niobium/tantalum mineralization.

The Samaqua property covers a magnetic geophysical response similar to the one associated with Niobec Inc.’s niobium mine. The magnetic signature lies 23 km southeast of the Crevier deposit and 130 km northwest of the Niobec mine. The magnetic response is circular in shape with a strong magnetic aureole surrounding a weak magnetic core, which is identical to the magnetic response of the Niobec mine. In the case of Niobec, the core corresponds to a niobium carbonatite with a rare-earth-rich centre.

The circular anomaly lies at the southeastern edge of a lineament visible on the regional geophysical survey maps of Quebec’s Ministère de l’énergie et des ressources naturelles (see map). The northwest end of the lineament coincides with the porphyry syenite dike that hosts the Crevier niobium /tantalum deposit, and the southeastern extension of the lineament could be the southeastern extension of the dike, which would connect the two systems.

The results of interpretation suggest that the magnetic signature to the southeast of the Crevier deposit could correspond to other carbonatite-type mineralization with a niobium or rare-earth centre. Furthermore, these would be related to the Crevier deposit by the lineament that could be the southeastern extension of the Crevier dike. The Samaqua intrusive is part of the Saguenay-Waswanipi structural corridor that includes the Saint-Honoré carbonatites (Niobec) and Crevier alkaline complex in the Grenville region and the Lac Shortt and Montviel carbonatite in the Abitibi region.

Map: Magnetic geophysical response of the Sasguenay-Waswanipi structural corridor 

Samaqua

Geology and mineralization

The property occurs in the Grenville geological province.  According to the regional geological map published by the Quebec government, the northern part of the property is underlain by migmatite and granitic rocks, including pegmatite, whereas the southern part is composed largely of coarse-grained porphyritic mangerite, an intrusive rock of intermediate composition typically found in metamorphic terranes of Proterozoic age like the Grenville.

The property occurs just to the SE of the Crevier Nb-Ta deposit, along the projected extension of the nepheline syenite dyke that hosts approximately 25.39 million tonnes (Measured + Indicated) at 1960 ppm Nb2O5 and 2349 ppm Ta2O5.  Historical prospecting work located pegmatitic syenite outcrops on the property, which are highly indicative of the presence of an alkaline intrusive favourable to metals like those at Crevier (niobium-tantalum) and /or Niobec (niobium and rare earths).


Six Graphite-Rich Zones at Buckingham Graphite Property, Quebec after airborne and ground geophysics

Posted by on Monday, 9 June, 2014

CAVAN VENTURES INC.  announces it has exposed graphite-rich zones as a result of trenching on its 100%-owned Buckingham graphite property, located adjacent to the historic Walker Graphite Mine in Buckingham Township, Quebec. Graphite-rich zones were exposed in six trenches, and channel samples were collected from two trenches over a combined distance of 59.5 meters. Graphite-rich outcrops at the same location as one of the trenches assayed at 21.7% C.

Peter Swistak, President of Cavan states, “We are extremely pleased that many of our airborne EM anomalies identified last year are now confirmed as graphite mineralization. Our ground geophysics was able to confirm the anomalies in real-time, which allowed us to quickly expose the mineralization and collect samples for assay. We anticipate highly positive results and intend to return for further exploration in the coming weeks.”

In May the Company engaged Magnor Exploration Inc. (La Baie, QC) to conduct a short exploration work program. Ground-based geophysics was used to ground-truth airborne EM anomalies identified last year using the PhiSpy portable TDEM system. PhiSpy generates real-time EM profiles of the area being surveyed, and can detect buried conductors to approximately 10m depth. Dube & Desaulniers Geoscience (Ottawa, ON) was engaged to collect 3.3 line-km of survey data over priority airborne EM anomalies using the PhiSpy system. The real-time interpretation of TDEM data allowed the Company to execute trenching on several high priority targets.

A total of six trenches ranging from four to 48 meters in length and two meters in width were completed. Trench 22C was cut for 24 meters in a northwest direction, with a second perpendicular trench cut at its southeast end for 20.5 meters. Graphite-rich zones were exposed in both directions, and channel samples were collected over most of both trench lengths for a total of 33.9 meters. Mineralization at Trench 22C is still open to the north, with some visible flakes in the trench up to one centimeter in diameter. A rock grab sample assayed previously from this location returned 21.7% C (see news release, July 8, 2013). Trench #1 was cut in a west-northwest direction, with visible graphite channel-sampled over 25.6 meters. Because of the rich nature of the mineralization, these samples and those from Trench 22C were immediately shipped for assay.

A new graphite zone was also discovered roughly 150 meters east of Trench 22C, where graphite-rich veinlets in granitic-pegmatitic rocks contain graphite flakes over 5 mm in diameter. Additionally, an airborne anomaly approximately 400 meters north of the main set of conductors was confirmed by PhiSpy, but the program ended before this new target could be tested through trenching.


After airborne EM: 71 m of Sulphide Mineralization in Felsic Volcanics at Homer Lake

Posted by on Tuesday, 13 May, 2014

TerraX Minerals Inc.  has received assay results from the first four holes drilled during the recently completed winter drill program at Northbelt, Yellowknife City Gold Project. These holes were drilled at the Homer Lake base metal target, which is located within 15 km of the city of Yellowknife and just 2 km from the new Bluefish Hydro Dam opened in July 2013. Assay results from nine holes drilled on TerraX’s two top priority gold targets, Crestaurum and Barney Shear, are pending and will be reported in the coming weeks, with the summer drill program expected to begin in late June 2014.

Two holes, TNB14-003 and TNB14-004, where drilled to test the down dip extension of surface showings sampled by TerraX in 2013 (chip samples of 7.0m @ 0.50 g/t Au 90.2 g/t Ag, 4.25% Pb and 0.89% Zn) and intersected felsic volcanics that are pervasively mineralized including multiple massive to semi-massive sulphide zones.

 

 

 

 

 

==================================================================

 

Highlights include:

        
        --  71.15m @ 0.25 g/t Au, 14.0 g/t Ag, 0.73% Pb and 0.57% Zn in hole TNB14-
            004 (inclusive of 3.42m @ 3.41 g/t Au, 69.3 g/t Ag, 3.67% Pb, 3.17% Zn
            in massive sulphides) and
        --  60.87m @ 0.11 g/t Au, 10.4 g/t Ag, 0.58% Pb and 0.65% Zn in hole TNB14-
            003;
               
===================================================================================
The Homer Lake drill program was designed to test a 400m-500m long VTEM (electromagnetic) anomaly with an interpreted steep westerly dip that had been identified by airborne surveying in 2013 and continues for a further 1km as a weaker VTEM anomaly to the south. 

Two holes (TNB14-001 and TNB14-002) were drilled with an easterly azimuth on sections 100m apart and designed to intersect the northern end of the anomaly. Holes TNB14-003 and 004 were drilled to the east of the anomaly in an area where base metals were identified in historic trenches during 2013 field work (eg. chip samples of 7.0m @ 0.50 g/t Au 90.2 g/t Ag, 4.25% Pb and 0.89% Zn). A map showing the location of these drill holes is available on our web site atwww.terraxminerals.com .

Higher grade intervals occur within the mineralized felsic volcanic unit, and also in the adjacent mafic volcanics (see table). Within TNB14-004 these include 3.42m @ 3.41 g/t Au, 69.3 g/t Ag, 3.67% Pb and 3.17% Zn within felsic volcanics; and 5.31m @ 0.40 g/t Au, 64.5 g/t Ag, 3.65% Pb and 2.64% Zn at a felsic to mafic volcanic contact. Within TNB14-003 high grade intervals include 4.44m @ 0.16 g/t Au, 25.5 g/t Ag, 2.10% Pb and 2.59% Zn at a mafic to felsic volcanic contact; 1.50m @ 1.70 g/t Au, 43.3 g/t Ag, 2.41% Pb and 2.04% Zn in felsic volcanics; and 2.02m @ 0.34 g/t Au, 85.1 g/t Ag, 4.08% Pb and 3.72% Zn at a felsic to mafic volcanic contact.

Joe Campbell, P.Geo, President of TerraX, states “The mineralization drilled in holes TNB14-003 and TNB14-004 is located along one of six sub-parallel zones of mineralization identified by TerraX in field work during the summer of 2013. Several of these zones have been traced over hundreds of meters of strike length on surface. While the high-grade gold targets at Northbelt remain our top priority, these wide zones of mineralization, coupled with the higher grade intervals of massive sulphides, are indicative of a large precious metal-rich base metal mineralized system in the Homer Lake area that definitely warrants further exploration when time and resources permit.”


Complex interpretation of geo data for Eskay Creek style mineralization in BC

Posted by on Tuesday, 6 May, 2014

Dolly Varden Silver Corporation announces the results from its geophysical program at the Dolly Varden property in Northwestern BC. The geophysical models further confirm drill targets for the Company’s proposed 2014 drill program and identify several new targets.

The newly compiled geophysical data outlines key horizons at depth and other surface anomalies that are coincident with known mineral showings, geochemical and structural targets already identified on the Dolly Varden property.

Dolly Varden

The combination of airborne MAG, VTEM, ZTEM radiometric, and geochemical data, along with geological and structural mapping, was used to define priority target zones. These helped define steep linear features, syngenetic faults, lithologic contacts related to basin formation, and key fluid controlling structures. In addition, key rock units, contact zones and alteration zones most likely to be associated with mineralization, were identified.
This compilation has demonstrated that the known deposits, showings, and related alteration zones are all located within a rift setting. The key rock units that infill the rift have also been identified, and these represent viable targets for Eskay Creek style VMS mineralization. Drilling will be conducted within corridors where mineralized occurrences and coincident alteration haloes point to extensive hydrothermal fluid flow. The key target areas for 2014 drilling include syngenetic VMS-style mineralization and associated feeder structures.

To view the image accompanying this press release, please visit the following link: http://media3.marketwire.com/docs/DV506-F1.pdf or visit www.dollyvardensilver.com.

——————————————————————————————————————————

The review of all available geophysical models identified six targets that are being recommended for follow-up work. Three of these targets are new and are located near the northern boundary of the Dolly Varden property and three of the identified targets confirm existing targets that are already scheduled for drilling in 2014.

The geophysical data adds information about the geometry and outlines the contacts between two key geologic horizons. In particular, the geophysics tracks the DVT Horizon to the north and under the Red Point area. Prior drilling on the DVT Horizon has intersected high grade silver mineralization that remains open to the north. The geophysics was also successful in outlining the Salmon River Formation that is prospective for Eskay Creek style mineralization. The geophysical results are congruent with, confirm, and add additional information to the targets slated to be drilled in 2014.

Further, the geophysical results indicate several new targets that have the potential for additional Eskay Creek style accumulations. These newly developed targets are located on the underexplored northern section of Dolly Varden’s property. The area is several kilometers to the North from the existing historical workings and abuts neighbouring exploration properties controlled by Homestake Resource Corporation and the Homestake – Agnico Eagle Mines joint venture.

The three targeted corridors are the 1) Torbrit-Red Point Corridor – following known silver mineralization underneath Red Point, an Eskay-Creek style target; 2) Musketeer Corridor – which runs along the east side of the Kitsault river with numerous Ag-rich epithermal vein-type showings with strong potassic radiometric signatures; and 3) Wolf-Surprise Corridor where an Eskay-Creek style host formation containing silver-rich VMS mineralization was identified by the Company’s 2011 drill program.

Geology

The geology underlying the Dolly Varden property consists of volcano-sedimentary rocks belonging mostly to the lower and middle Jurassic Hazelton Group. These include intermediate volcanic and volcaniclastic rocks of the Betty Creek Formation and bimodal volcanic and sedimentary rocks of the Salmon River Formation.

The principal silver-base metal deposits of the Kitsault River valley have been interpreted as vein mineralization by early workers. Devlin (1986) reinterpreted the main deposits to be volcanic exhalative in origin. Deposits of this type are formed as sub-aqueous hot-spring type deposits on the seafloor, as products of hydrothermal solutions that have vented from sub-seafloor fracture and fault systems. Furthermore, the silver deposits of the upper Kitsault valley are mapped with important geological similarities to the Eskay Creek deposit, providing an analog for exploration on the Property.


Magnetic/VLF survey in the Chibougamau area in Quebec

Posted by on Tuesday, 6 May, 2014

 Stellar AfricaGold Inc. announces that an airborne Magnetic/VLF survey has been completed over the Opawica and Philibert I properties in the Chibougamau area in Quebec. An exhaustive interpretation done by MB Geosolutions inc., has outlined (8) gold and (3) Cu-rich polymetallic exploration targets. The interpretation was done by analysing current survey data in association to existing INPUT EM combined with Cu till anomalies from public data sources. Two of the copper targets are located in the Opawica South Block and one in the Philibert I Block. Four (4) gold targets are located in the Opawica North Block, three (3) in Opawica South Block and one (1) target in Philibert I Block.

The Company is now planning the spring/summer reconnaissance over Opawica and Philibert I property with an emphasis on the evaluation and sampling of the targeted area. A ground IP survey should be recommended to better outline the targets that are not outcropping. Trenching and drilling should follow during summer program over selected targets.

About OPAWICA and Philibert I Property:

The Opawica and Philibert 1 properties are located in the Chibougamau-Chapais mining camp within the Tomagold/Iamgold-Vanstar-SOQUEM working area which is to date the most active exploration camp in Quebec. Among the most important gold occurrences reported in the area, we note SOQUEM Meston Lake deposit (1.2 MT @ 6.25 g/t Au), SOQUEM Philibert deposit (1.3 MT @ 5.32 g/t Au), as well as numerous high grade drill and channel sampling reported by Tomagold, Vanstar, Murgor and SOQUEM as well as the former Joe Mann gold mine that produced over 1.0 million ounces of gold.

The OPAWICA Property consists of three blocks totalling 80 mining cells recently acquired by Stellar in the area of the new Liam gold discovery of the Nelligan Project of Vanstar. The Philibert 1 property is composed of one block of four mining cells and is part of the same area.

The Philibert-I showing was discovered in 1983 by prospection, and consists of a gold mineralization associated with quartz-tourmaline-sulphides veins. Historical exploration reported grades of 31.6 g/t Au and 2.54 g/t Ag in channel sampling across exposed quartz veins, and of 18.66 g/t Au over 0.6-metre cuts in a drill hole.


Airborne and ground geophysics for precious metal project in Mexico

Posted by on Monday, 5 May, 2014

Orex Minerals Inc. announces completion of an airborne geophysical survey at its Los Crestones precious metal project, Sinaloa, Mexico. The 4,168 hectare helicopter-borne radiometric and magnetic survey was flown at 50m line spacing by MPX Geoservices Ltd. Data are being processed and results are expected in the coming weeks. In addition, Orex has signed a contract with Quantec Geoscience Ltd (“Quantec”) to undertake an 18 line-kilometre TITAN 24 DCIP (Direct Current resistivity and Induced Polarization chargeability) ground geophysical survey.

The proposed survey comprises 5 lines, each 3.6km long and 400m apart and will be the first ground geophysical survey to be conducted at Los Crestones. During the work Quantec will also collect MT (Magnetotelluric resistivity) data on the central grid line. Scheduled to commence mid-May, the survey is centred over mineralized structures previously tested by shallow diamond drilling in 2011. Orex expects the results to augment existing geophysical, geochemical and geological datasets and intends to use the results to identify additional areas for drill testing later in 2014. Surveying and clearing of grid lines is currently underway.

According to Orex’s President, Gary Cope, “The known mineralized structures may be only a portion of the bigger picture at Los Crestones. Utilization of airborne and deep penetrating surface geophysics at this stage of exploration will allow our geological team to refine drill targets for testing in the latter half of 2014. “

The property was drilled previously by Astral Mining Corporation (“Astral”) now merged with Orex (news release February 12th, 2013). In late 2011 Astral completed 2,618m of HQ and NQ diameter core drilling in 18 holes. Drilling tested three mineralized structures which outcrop at surface. Significant intercepts were identified in many of the holes and may be viewed at www.orexminerals.com/s/Drilling-LosCrestones.asp. Reported results included a best intercept of 5m averaging 39.1 g/t Au, 93.3 g/t Ag and 2.13% Cu from 55m depth in HQ drillhole 11LD011. True width of this interval from the Bohemia structure is approximately 3.53m.

LOS CRESTONES GOLD-SILVER-COPPER PROJECT SINALOA, MEXICO

The Los Crestones project totals 4,168 hectares and is prospective for economic gold, silver and copper mineralization. Mineralization includes north-south oriented structural zones hosting quartz veins, quartz stockworks and breccia fill possibly related to a deeper porphyry and/or diatreme system. Three main structural zones were targeted in the first phases of work. Corona, Bohemia and Indio are elongate structures recognized on surface as erosion-resistant silicified ribs or “crestons”. The airborne and ground geophysical programs commissioned by Orex are designed to complement ongoing geological mapping and geochemical sampling. Orex intends to develop drill targets over the summer; diamond drilling is scheduled for late 2014.

Geology and Mineralization

The property is underlain primarily by volcanic and intrusive rocks. At lower elevations andesite and dacite are seen within an erosional window in creeks and drainages and are representative of the “Lower Volcanic Sequence” commonly recognized throughout western Mexico. At higher levels the sequence is capped by rhyolites of the “Upper Volcanic Sequence”. Felsic to intermediate intrusive rocks are also observed over a large proportion of the property. The INEGI 1:50,000 G13-C12 map sheet depicts two intrusive bodies on Los Crestones though Orex geologists have observed outcropping intrusive material across the property.

Mineralization is concentrated within a series of silicified, north-south trending quartz stockwork and breccia zones most prominent in the southern half of the property. Three structures subject to the most work to date are named “Corona”, “Bohemia” and “Indio”. Historically these structures have been tested in small pits and underground workings, many of which are still accessible today, the largest comprising some 40 m of development. Additional mineralized structures have also been identified and require follow up work.