Posts Tagged spectrometry

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.


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.

 


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.

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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.


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.


Supervised Neural Network Targeting and Classification Analysis for Mineral Exploration

Posted by on Tuesday, 29 April, 2014

Karl Kwan (Geotech LTD) presented at Canadian Exploration Geophysical Society meeting (8 April 2014) methodology and examples of using Neural Network Targeting and Classification at mineral exploration.

“Geophysical survey contractors routinely offer multi-parameter data to clients. For example, a helicopter-borne survey may acquire Time-domain electromagnetic (TDEM), magnetic gradiometer and even gamma-ray spectrometer data (i.e., VTEMplus, Geotech LTD). Exploration geophysicists can certainly take advantage some of the readily available multi-disciplinary (geology, geophysics and remote sensing) and multi-parameter (potential field, EM, gamma-ray spectrometry, and others) datasets for mineral exploration. However, the integration and interpretation of these datasets can be time-consuming and even challenging, especially for large-scale datasets covering large areas with diverse geological conditions. The Supervised Neural Network (NN) Targeting and Classification technique for mineral exploration described and demonstrated by Reford, Lipton and Ugalde, 2004, “Predictive Ore Deposit Targeting Using Neural Network Analysis” (http://www.pgw.on.ca/downloads.html), can be a useful and promising tool for the analysis of multi-disciplinary and multi-parameter data.

In this presentation, the properties or responses of the two feed-forward multilayer Neural Networks, Levenberg-Marquardt (NN with LM training) and Fast Classification (FCNN), as implemented in the current version by PGW, are studied in detail. The supervised NN simulations are performed on specially constructed synthetic data. Intended as a tutorial and the NNs treated as black boxes, the objectives of the exercise are twofold, to demonstrate the targeting as well as classification capabilities of the Neural Networks, and at the same time to show one of the known limitations and to suggest a way to get around it. The utility of the NN tool is demonstrated again with real cases from the Republic of Niger.”

Geosoft is delighted to host the online portion of the Canadian Exploration Geophysical Society meeting with keynote speaker Karl Kwan, Geotech LTD.

YouTube:  


Integrated airborne geophysics and geologic data interpretation for new Eskay-Creek style deposits

Posted by on Wednesday, 9 April, 2014

Dolly Varden Silver Corporation announces that through recent geoscience modeling and ongoing interpretation, the Company has focused its primary advanced exploration target areas on three corridors within the Dolly Varden property. Work is now being done to prioritize the most prospective drill-ready targets within these corridors. The corridors and targets were chosen for their potential to best expand areas of known high-grade silver mineralization and to identify new Eskay-Creek style precious metals deposits.

 

 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.

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Through recent modeling and ongoing interpretation, the Company has now moved from kilometer scale targeting to meter scale targeting within these defined corridors. The Company’s technical team is working to delineate specific drill ready targets within these corridors. An aggressive 40 to 50 hole (13,500 meter drill program) is being finalized, subject to financing.
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.

High Resolution Airborne Geophysical Survey in Tanzania

Posted by on Sunday, 19 January, 2014

Geological Survey of Tanzania (GST) and Ministry of Energy and Minerals of Tanzania have organized the Workshop “Launching High Resolution Airborne Geophysical Data at Julius Nyerera Convention Center (17 January, 2014, Dar es Salaam, Tanzania). Around 150 delegates have attended the workshop from government and private sectors.

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Geotech Ltd. and Sander Geophysics have finished the airborne magnetic, gravity, electromagnetic (VTEM), radiometric surveys in 31 districts and presented some results of the surveys.

Permanent Secretary (PS) of Ministry of Energy and Minerals Mr.Eliakim Maswi said – the surveys were carried out under the Sustainable Management of Mineral Resources Project, saying the purpose of the survey was to identify potential zones of mineralization. “The main objective of the project is to improve the socioeconomic impacts of mining for Tanzania and Tanzanians and therefore enhance local and foreign investments”, said PS.

GST Chief Executive Officer , Prof. Abdulkarim Mruma said: “geophysical data acquired through the high resolution airborne geophysical surveys allow fast and accurate delineation of mineralised targets and when augmented with geological and geochemical datasets are highly effective in attracting new exploration ventures.” Prof. Mruma noted that the availability of the modern geo-scientific  data will stimulate investments into mineral and other sectors and will improve the effectiveness of exploration programs.

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Photo: A.Prikhodko


The Results of a Three Methods Airborne Geophysical Survey Over the Kirkham Property in BC

Posted by on Friday, 20 December, 2013

Metallis Resources Inc. announces the receipt of a report summarizing the results of an airborne geophysical survey over its Kirkham Property (the “Property”), situated in the prolific Golden Triangle area of northern British Columbia. The helicopter-borne versatile time domain electromagnetic (VTEM), magnetometer and gamma-ray spectrometry geophysical survey covered 57 km2 of the Property at 250-metre line spacing.

These data indicate a number of anomalous electromagnetic zones (conductors) are present across the survey block. Refer to the attached map for reference. Several of the isolated VTEM anomalies are coincident with conductors that were identified by earlier airborne surveys. In general, electromagnetic (EM) anomalies follow magnetic trends, are commonly associated with local magnetic anomalies and show good correlation with thorium/potassium ratio gamma-ray anomalies.

The isolated anomalies could correspond to the volcanogenic massive sulphide (Eskay Creek -type) or the shear/vein (Snip Mine-type) exploration models. The large anomalies could be related to porphyry copper/gold systems (i.e. Red-Chris, Galore Creek, and Mt. Milligan).

A 2 km diameter area of magnetic high (>100nT) with coincident low resistivity occurs in the north-central part of the survey area. The area’s low resistivity character is interpreted to be caused by alteration and possibly sulphide mineralization. The elevated magnetism is interpreted to be the expression of an intrusive body which could be the source for the mineralization discovered to date. A weak thorium/potassium ratio high coincides with this area consistent with a dioritic composition intrusion. According to apparent resistivity depth imaging over selected lines, the estimated depth to the top of this target is roughly from 50 to 100 meters. This anomaly corresponds to a large gold-in-soil anomaly where numerous mineralized veins were discovered in the 1980s by trenching through the deep overburden. A channel sample of a vein from one of these trenches returned 16.2 g/t (grams per tonne) gold over 0.4m. Another channel sample assayed 1.72 g/t gold over 6m. The whole area of the anomalous mag/EM response is deemed prospective for discovery of new mineralized zones.

One of the major coincident VTEM/magnetic/radiometric anomalies is correlated with the known distribution of the Hawlison monzonite which belongs to a suite of Jurassic alkali feldspar-plagioclase-hornblende-porphyries. Compositional similarities would suggest that the Hawlison monzonite be grouped with the Eskay Porphyry of the Texas Creek Plutonic suite. At the south end of the above mentioned quartz monzonitic intrusive, a zone of increased EM response, again associated with a magnetic low, occurs on the west side of the mapped intrusive, and in the vicinity of mineralized showings. In particular, a strong conductor occurs at the west end of one of the survey lines. A limited amount of drilling and trenching has identified copper and gold mineralization occurring over a 3.5 kilometer-long section of this intrusion. In 2010, Paget discovered a zone of higher grade copper-gold mineralization of up to 1.3 g/t gold and 0.57% copper extending up to 1.5 kilometers south of existing drilling. Fourteen rock chip samples of quartz-sericite-pyrite altered porphyry with quartz-chalcopyrite veins and stockworks averaged 0.4 g/t gold and 0.22% copper, including values up to 1.3 g/t gold and 0.57% copper. Twenty-two rock samples, including eight historical sample assays, from the 190 metre wide zone average 0.7 g/t gold and 0.35% copper.

Directly west of the 2 kilometre sized magnetic/resistivity anomaly mentioned above, a localized EM and magnetic response occurs on two lines near the base of a steep north facing slope. This response is particularly interesting since regional geochemical silt sampling downslope generated highly anomalous Cu/Zn/Au/As values. The directly associated negative 300nT response suggests remanence magnetism from a body emplaced at a time when the earth’s field was reversed. Modeling of the VTEM electromagnetic response suggests a 15 Siemen, west dipping, approximately 300 metre long target at a shallow depth of about 40 metres. The combined strong geochemical and geophysical response is interpreted as a possible gold bearing massive sulphide target. It occurs about 200 metres west of the Hawlison monzonite. This target is about 20 kilometres southwest of Eskay Creek mine.

The isolated conductors have not been tested to date and represent very attractive targets suitable for follow-up. In several cases, these conductors are related to silt and soil geochemical anomalies or prospective rock-types such as rhyolites.

All of the airborne geophysical information is being interpreted by a senior geophysical consultant in order to outline and define the significant anomalies that were identified.

These anomalies should be evaluated by mapping, soil geochemistry, ground geophysics and trenching in order to define a prioritized set of drill targets.


Geoscience Program in Colorado

Posted by on Wednesday, 18 September, 2013
NEOS GeoSolutions, Inc. announced that it has secured underwriting for a multi-client, integrated geological and geophysical program in Colorado, the second project NEOS has undertaken in the state this year. This newly announced neoBASIN™ project covers 3,000 square miles over the Denver-Julesburg (D-J) Basin, a sedimentary basin that reaches its deepest point near Denver and then extends northward into southeastern Wyoming and the western parts of Kansas and Nebraska. NEOS’s Denver-Julesburg geoscience program has been designed to provide a regional view into the subsurface from the basement through the target reservoir intervals, including the liquids-rich Niobrara shale. By applying an advanced geostatistical technique known as predictive analytics, NEOS will be working on behalf of the project’s underwriters to identify the geological and geophysical measurements and attributes that correspond to the best producing wells in the area of investigation and to determine where similar areas occur in less developed parts of the survey area.
Lance Moreland, Director of Rockies Programs for NEOS, commented, “We’ll be acquiring new airborne geophysical datasets – magnetic, electromagnetic, radiometric, and gravity –and integrating these with existing seismic and well information. We’ll analyze all of the acquired datasets individually, but also interpret them simultaneously to determine the measurements, attributes, and derivatives that correspond with the best wells in the basin. Our predictive analytics methodology will then ‘pattern search’ for these same measurements in less developed parts of the area being studied. This is our standard neoBASIN workflow, though we’ll tailor it slightly to test some of the specific hypotheses operators have about the drivers of Niobrara productivity, including basement topography, basement faulting, and regional intrusive activity.”
The neoBASIN survey is being exec ted under a multi-client commercial model. The window for late underwriters will close on January 15, 2014. Final results should be available to the project underwriters in the first half of 2014. To learn more about NEOS’s multi-measurement methodology for oil & gas exploration and development, read the white paper at: tinyurl.com/MMI-WhitePaper. To learn more about NEOS’s regional imaging programs in the D-J, Piceance, and Sand Wash basins of Colorado, visit: tinyurl.com/neos-Colorado.


Airborne Geophysical Survey Underway at Brahma/Austral Project

Posted by on Wednesday, 18 September, 2013

Condor Resources Inc.announces that MMG Chile Exploration SPA (“MMG”), a subsidiary of MMG Limited, has commenced an airborne geophysical survey over Condor’s Brahma/Austral porphyry copper project in southern Chile.

The survey is being conducted by New-Sense Geophysics Limited and includes airborne radiometrics and magnetometer surveys utilizing a Eurocopter AS350 B3. Approximately 3000 line-kilometres will be flown at 150m line-spacings, and it is anticipated that the survey will be completed before the end of September.

Condor recently signed an agreement giving MMG a 270 day exclusivity period to conduct a mandatory due diligence program at Brahma/Austral, which due diligence includes the airborne survey, and follow up mapping and sampling. If MMG decide to proceed with an option agreement, they will be required to complete cumulative exploration expenditures of US$7 million, and complete a Preliminary Economic Assessment, both within 6 years of execution of the option agreement, in order to earn a 70% interest in Brahma/Austral.

The Brahma/Austral concessions cover some 186 sq km situated southeast of the city of Talca in southern Chile. The project is located on the southern extension of the West Fissure fault system, the continental scale structure which controls most of the large world class copper deposits located within the central Andes of Chile, including the El Teniente mine located 200 km to the north.

Geology/Mineralization:

In 2006, Dr. Richard Culbert discovered a highly anomalous stream sediment sample at a location called Los Boldos Creek. In 2007 Condor geologists, attempting to locate the source of the copper anomaly within the creek, identified and traced float boulders containing finely-disseminated chalcopyrite and covellite in a pervasive quartz-sericite (“phyllic”) altered quartz feldspar porphyry intrusive (QFP) to a tributary of the main creek and then to an outcrop where copper sulphides occur as disseminations, localized stockwork veinlets and fracture coatings. Subsequent prospecting approximately 300 m vertically above this outcrop located additional pervasive-altered and leached QFP in bedrock, with hematite and lesser jarosite occurring as disseminations, in stockwork veinlets and on fracture surfaces within the intrusive. This type of alteration closely resembles the leached capping commonly occurring above most Chilean porphyry copper deposits. Abundant finely disseminated chalcopyrite, covellite and pyrite occur at the base of the intensely-altered system.


Continuing of geophysical investigations at Patterson Lake for uranium

Posted by on Tuesday, 17 September, 2013

Forum Uranium Corp. announces further exploration of its 100% owned Clearwater Project on trend and immediately adjacent to the southwest of the Alpha Minerals/Fission Uranium Patterson Lake South discovery. Forum conducted ground radiometric prospecting, lake sediment geochemical surveys and soil gas radon surveys in late August/early September.

As a result of this program, further prospecting of airborne radiometric anomalies and expansion of the radon survey will take place. The radon survey has outlined a number of anomalous zones on two grids immediately southwest of the Alpha/Fission claim boundary. These results are very encouraging so the grids will be expanded to cover areas with airborne electromagnetic conductors on strike with the Patterson Lake South conductive trend. Upon completion of this follow-up program, Forum will conduct ground electromagnetic surveys this fall and ground gravity in early winter to outline targets for drilling in late January 2014.


The uranium “BOULDER-FINDING” technology and the application results

Posted by on Thursday, 29 August, 2013

FISSION URANIUM CORP. and Special Projects Inc (SPI, Calgary), are pleased to announce the filing of a patent application for an invention entitled “System And Method For Aerial Surveying Or Mapping Of Radioactive Deposits”. The invention relates to an airborne system and method for surveying a geographic area to detect and map the locations of radioactive geological deposits, such as boulders and clusters of rock.

The invention results in a particularly high-resolution survey and is an improvement over known airborne surveying methods for radioactive deposits. The invention led Fission to discover the high-grade uranium boulder field at its Patterson Lake South (PLS) property in Canada’s Athabasca Basin, home to the world’s richest source of high-grade uranium.

Ross McElroy, President, COO and Chief Geologist of Fission Uranium, commented,

Using our patent-pending survey system, enables us to quickly and effectively explore large areas for radiometric anomalies. Our system has proved to be incredibly sensitive and accurate in locating anomalies of interest and provides a “leading-edge” ability to find occurrences of radioactive soil, boulders and outcrop at surface that may represent uranium.”

Radiometric surveys are regularly employed in exploration to detect and map natural radioactive emanations (from uranium, thorium and potassium), from rocks and soils. Meteorological conditions, the topography of the survey area, the influence of the Earth’s cosmic environment, the height of the sensor above ground and the speed of the aircraft are some of the variables which affect radiometric measurements. The invention resulting from the collaboration between Fission’s technical team and SPI is particularly sensitive to addressing these variables.

Prior to the Fission/SPI invention, airborne prospecting for radioactive minerals has been generally carried out by flying a fixed wing aircraft equipped with large detectors relatively high altitudes and high speeds over a geographical region to be surveyed. However, data collected in such a manner often does not allow for detection of localized geological deposits such as boulders and clusters of rock due to the large footprint of the measurement and the resulting background-to-boulder signature ratio. Additionally, many legacy systems, which used a combination of towed magnetometer sensors and large detector systems, lacked the electronic navigation and data acquisition tools required to collect and compile the information in a manner required to detect localized geological deposits.

The Fission/SPI invention utilizes a fixed wing aircraft using at least one radiation detector element to fly at an ideal height and speed over a geographic area and store the radioactive signal data. Furthermore utilizing advanced processing technology to map the radiation signal data to accurately identify and flag high priority points, which in the case for PLS resulted in the discovery of the high-grade uranium boulders.

FISSION URANIUM CORP. announces the discovery of two significant and strongly radioactive uranium source anomalous regions on its 100% owned North Shore property in the Athabasca Basin, Alberta. The Northern and Southern anomalies occur within the south-central part of the project area near the southern boundary. The discovery was made using Fission and Special Project Inc’s (‘SPI’) high resolution magnetic and radiometric airborne survey technology which is currently patent-pending (see news release July 16, 2013).

The Northern anomalous region occurs within a 1.5km x 0.5km area and contains several parallel trends up to 300m.  The Southern anomaly is located approximately 7km to the SW of the northern anomaly and is characterized by being narrow (1 to 10m wide) and can be traced for up to 3km.

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

We are very encouraged by this strongly radioactive discovery, particularly as we used the same technology to locate the boulder field at Patterson Lake South (PLS). While the expansion of our PLS discovery is our main task, following up these new results at our North Shore property is also a priority.

In August 2013, using a fixed wing aircraft, SPI flew a 12,257 line km high resolution airborne magnetic and radiometric survey at 50m line spacing over the entire North Shore project.  The radiometric system uses a calibrated gamma spectrometer which is able to differentiate between uranium, thorium and potassium and also determine the relative concentration of each element.

The radiometric data was collected and processed and anomalies were picked based on elevated total counts with correlated elevated uranium concentrations.  The width and responses of the peaks indicate that some of the larger anomalies present are likely to be part of the outcrop/sub crop as opposed to boulders.  This is indicated by a generally wider anomaly which is easily seen on multiple lines.


Airborne EM and radiometric surveys for Saskatchewan uranium exploration

Posted by on Thursday, 8 August, 2013

Noka Resources Inc. announces that the members of the Western Athabasca Syndicate; Noka Resources Inc.Skyharbour Resources Ltd., Athabasca Nuclear Corp., & Lucky Strike Resources Ltd.(“the Syndicate”) have completed large-scale VTEM plus and radiometric geophysical surveys on the Western Athabasca Syndicate Project located near Alpha Minerals’ and Fission Uranium’s  Patterson Lake South (“PLS”) uranium discovery. The original airborne coverage was expanded to provide for the infill and extension of conductive anomalies and structural features identified by a preliminary review of the geophysical data. Based on this initial encouraging data, the Syndicate has elected to immediately commence the second phase of its summer program consisting of follow-up field work and ground-truthing of geophysical targets.

Western Athabasca Syndicate Project Claims Map: http://www.nokaresources.com/images/NX-Western-Basin-Syndicate.jpg

Completion of Regional Airborne Geophysical Survey:

A total of 4,840 line kilometres was flown for the VTEM plus time domain survey with an additional 4,400 line kilometres flown for the radiometric survey all of which was on the Syndicate’s Preston Lake Property. The VTEM plus system has been used successfully to locate basement conductors similar to the structures that host the high-grade uranium discoveries at the nearby PLS project. The high resolution radiometric survey was flown to locate uranium boulder trains, in-situ uranium mineralization and alteration associated with uranium mineralization which is what ultimately led to the PLS discovery by Alpha and Fission. Phil Robertshaw (P.Geo., Saskatchewan) is reviewing the collected data and will be providing detailed interpretation of the VTEM plus and radiometric surveys shortly.

Western Athabasca Syndicate Airborne Survey Coverage: http://nokaresources.com/images/NX-Geophysics-coverage.jpg

The areas flown include two blocks in the northern part of the Preston Lake Property. The Preston Lake South block is contiguous with Fission Uranium and NexGen Energy and includes a large area of partially exposed pre-Cambrian shield rocks. The Preston Lake West block claims are contiguous with claims controlled by Aldrin Resources and Forum Uranium. The claims are underlain by Phanerozoic rocks (limestone and sandstone) similar to the PLS discovery area. At Fission and Alpha’s PLS high-grade discovery it is interpreted that the uranium has been mobilized along the fault zones and has been concentrated in the sandstone under the limestone. A review of historic data on the Preston Lake Property has identified a sample collected by the Geological Survey of Canada which returned a value of 5.4 ppm U3O8, considered to be significant in an area with a background uranium value of 1 ppm U3O8. This high U3O8 value may indicate either the down-ice glacial transport of uranium boulders from source or an in-situ source of uranium. For comparison, the highest value down-ice from the PLS discovery is 3.2 ppm U3O8. Management cautions that past results or discoveries on proximate land are not necessarily indicative of the results that may be achieved on the Western Athabasca Syndicate Project.

Commencement of Field Program at Preston Lake Property:

The initial data and results from the airborne surveys have led the Syndicate to expedite the planned summer field program with a number of high-priority targets at the Preston Lake Property being the focus of the work. A sophisticated targeting matrix is being used to further identify and prioritize areas for ground-based follow-up. Field work will include ground-truthing of high-priority geophysical targets using water and soil radon sampling, biogeochemistry, geochemical lake sediment and soil sampling, prospecting, and scintillometer surveying. The Syndicate will employ a systematic, proven and cost-efficient exploration methodology that has led to numerous uranium discoveries in the region and throughout the Athabasca Basin. By the end of this summer’s field program, a total of $1.5 million will be spent in exploration on the project between airborne geophysical surveys and follow-up ground work.

Uranium and the Athabasca Basin:

The Athabasca Basin of northern Saskatchewan hosts the world’s largest and richest high-grade uranium deposits accounting for just under 20% of global primary uranium supply. Athabasca uranium deposits have grades substantially higher than the world average grade of about 0.1% U3O8. The Patterson Lake area has received escalating exploration attention and claim acquisition activity as a result of the new, shallow discoveries made by Alpha and Fission which includes the recently reported drill interval of 6.26% U3O8 over 49.5 metres in drill hole PLS 13-053. This mineralized zone is located approximately 400 metres to the northeast of discovery hole PLS 12-024 which returned 2.49% U3O8 over 12.5 metres. Consistent high grade, near surface U3O8 assays from Alpha and Fission demonstrate the potential for high grade uranium mineralization on the margins of the western side of the Athabasca Basin. There are still areas in the Athabasca region that are highly prospective and underexplored for high grade uranium as illustrated by Alpha’s and Fission’s recent discovery.


Airborne EM and radiometry in Western Athabasca

Posted by on Tuesday, 23 July, 2013

Noka Resources Inc. announces that the members of the Western Athabasca Syndicate; Noka Resources Inc. Skyharbour Resources Ltd. , Athabasca Nuclear Corp., & Lucky Strike Resources Ltd.(“the Syndicate”) have completed an additional 720 line kilometres to the 4120 line kilometre VTEM plus time domain geophysical survey on the Western Athabasca Syndicate Project. The additional coverage consisted of infill and extension of conductive anomalies and structural features identified by a preliminary review of the geophysical data.

The Syndicate is also pleased to announce that the high resolution airborne radiometric survey on the Western Athabasca Syndicate Project has started. The contract was awarded to Goldak Airborne Surveys who will be collecting radiometric data be using a digital acquisition system that is proprietary to Goldak. A total of 4400 line kilometres at 200 metre line spacing will be flown using a 50.4 liter crystal volume detector to locate uranium boulder trains, in-situ uranium mineralization and alteration associated with uranium mineralization systems.

The Syndicate is using Phil Robertshaw (P.Geo., Saskatchewan) to review the VTEM plus and radiometric data and provide detailed interpretation when the surveys are completed.

Western Athabasca Syndicate Project claims map


Geophysical surveys in Colombia for VMS

Posted by on Thursday, 18 October, 2012

CuOro Resources Corp. announces that Geotech Ltd. of Aurora, Ontario (“Geotech”) has been engaged to complete a 416 line-kilometre, helicopter-borne versatile time-domain electromagnetic (“VTEM”) survey of the Santa Elena Copper-Gold Project, in Antioquia Department, Colombia.

Geotech’s VTEM system has been shown to be excellent at identifying conductive, massive-sulphide bodies as well as mapping lateral and vertical variations in resistivity. The VTEM system is also equipped with a high sensitivity magnetometer which can aid in mapping geologic structure and lithology.

The survey is expected to be completed during October 2012. The Company will immediately investigate any targets generated by the survey with exploration and drilling.

Santa Elena Overview

Santa Elena is classified as a bimodal-mafic VMS deposit. This type of deposit is similar to that found in many of the major district of the Precambrian Shields of Canada, Western Australia, and Scandinavia, as well as the Urals and in the Cretaceous of Peru. The latter is comprised of the giant Tambo Grande deposits; TG1 and TG3, adjacent deposits comprising a single ore system contain a non 43-101 compliant resource of over 138 MT of 1.3% Cu and 1.1% Zn. The Tambo Grande deposits are in a very similar setting to the Santa Elena occurrence, and given that both are in what appears to be an oceanic back-arc setting, this district may be a model for Santa Elena. It is important to note that VMS deposits almost always occur in districts, and that their sizes are log-normally distributed.

The concessions contain 1,287.5 hectares near the north end of the Antioquia batholith, at the intersection between the San Pablo formation (Cretaceous marine sediments) located to the north, the basaltic volcanic flows located to the west, and the Antioquia batholith quartz-diorite complex to the east.

The infrastructure is excellent and includes paved road access, two hydroelectric plants within 5 km, and abundant water supply.

Geological mapping and sampling has identified 3 VMS areas of outcropping (TEM-1, TEM-2, and TEM-3) all of which coincide with historical geophysical anomalies. Several new mineralized outcrops have been located recently south of the known VMS outcrops.

Recently completed geophysical surveys have validated the historical data, as well as produced many new targets which will be drill tested.

Summary of Geophysics

A surface geophysical TEM survey at 50 m intervals was conducted on a selected area of the property where outcropping mineralization was visible. The survey was conducted by VAL D’OR Geophysics for Noranda Mining and Exploration Inc in 1996-1997.

The historical ground geophysics had identified 4 strong conductors with good vertical extent, 3 of which are coincident with the TEM-1, TEM-2, and TEM-3 outcrops.

An airborne magnetometer and radiometric survey was flown in August 2011. These surveys were followed-up by ground based induced polarization and resistivity surveys. These surveys validated the original survey data, and also generated several new drill targets which are currently being drill tested.

The company plans to initiate down-hole TEM surveys along with additional induced polarization and resistivity surveys in January 2012.


The New Potential Ni-Cu targets in Tanzania

Posted by on Friday, 7 September, 2012
IMX Resources Limited reports the identification of twenty-five new high priority VTEM anomalies from the recently completed airborne magnetic and versatile time-domain electromagnetic (VTEM) survey over selected areas within the Nachingwea Nickel-Copper JV Project located in southeast Tanzania.
The delineation of multiple late time EM anomalies further enhances the regional prospectivity of the Nachingwea JV property. Of potential significance is the identification of a high amplitude late time EM anomaly coincident with the Hog gold prospect, where surface gossan sampling returned values of up to 4.96 g/t Au and 0.64% Cu (ASX: May 28, 2012).
Patricia Tirschmann, VP Exploration, commented: “We are pleased to have completed another successful regional VTEM survey and are very encouraged by the number of high quality targets generated. The identification of an EM anomaly coincident with the Hog gold prospect further enhances the exploration potential of this target and we look forward to drill testing it and other high priority targets beginning in September.”
The airborne geophysical survey was carried out by Geotech Limited of South Africa employing the Versatile Time-Domain Electromagnetic (VTEM) geophysical system. The survey ran from July 29th to August 11th and a total of 2,409 kilometers were flown in five flight blocks.
The flight blocks comprising the 2012 airborne VTEM survey were selected by prioritizing areas based on results of the 2010 airborne magnetic and radiometric survey in combination with results of geochemical sampling and geological mapping. Preliminary data from the new VTEM survey is currently being evaluated, and targets are being selected for ground follow-up in order to help prioritize anomalies for drill testing later in the year.
Analysis of the preliminary VTEM data indicates that EM anomalies have been detected on each of the five flight blocks and approximately twenty-five of these represent high priority anomalies with late channel responses. Of potential significance is a high amplitude late time EM anomaly detected on three 200 metre spaced flight lines which is coincident with the Hog gold prospect where surface gossan grab samples returned values of up to 4.96 g/t gold and 0.64% copper (May 25, 2012 Press Release). Several other VTEM anomalies are also confirmed to have coincident copper and/or nickel in soil anomalies.
The Company plans to carry out 1,500-2,000 metres of reverse circulation drilling to test selected high priority regional VTEM and geochemical anomalies including the Hog gold prospect. This drilling is currently expected to begin in mid-September.

Exploration activity at Nachingwea has identified several zones of nickel sulphide mineralisation, at Ntaka Hill, where a combined Measured and Indicated Resource of 12.79 million tonnes (Mt) grading 1.21% Ni (using a 0.2% Ni cut-off) has been announced. The resource equates to an estimated 154,700 tonnes of contained nickel.

In addition, an Inferred Mineral Resource of 45.04Mt @ 0.3% Ni (using a 0.2% Ni cut-off) has been identified at Ntaka Hill.

A positive scoping study for an open pit mining operation means that the Nachingwea project is now advancing towards a potential production commencement date in 2015.

Read more..


Helicopter Magnetic and Radiometric Survey on Anza Property in Colombia

Posted by on Saturday, 16 June, 2012

Waymar Resources Ltd.  announces the completion of a 2,867 km helicopter magnetic and radiometric survey, covering approximately 260 km2, over their Anzá project in Antioquia, Colombia. Preliminary data images can be found on the Waymar website at the following links:

http://www.waymarresources.com/_resources/maps/RTPAnza_image1.jpg

http://www.waymarresources.com/_resources/maps/RTPAnza_image2.jpg

http://www.waymarresources.com/_resources/maps/RTPAnza_image3.jpg.

The survey was completed by MPX Geophysics Ltd., of Markham Ontario, at a nominal altitude of 70m and 100m traverse line separation. The results will be used to aid geologic mapping, identify structures and alteration associated with hydrothermal mineralization and possible porphyry copper-gold systems within the project area. The survey data is currently being processed by MPX and final products are expected by July 2012.

Waymar has also completed a structural evaluation using Radar images over the entire area of the land package held in the Anzá district. The images were acquired, processed and interpreted by Alto Americas S.A., of Buenos Aires, Argentina, a company that specializes in remote sensing products and services.

“The preliminary geophysical data confirms that the Aragón structure, which controls the gold mineralization at the Anzá deposit, is a continuous, district-wide feature,” commented Pablo Marcet, CEO. “The combination of Magnetics and Radiometrics is giving us a powerful tool to identify and prioritize targets in our extensive land package. Together with the interpreted Radar images, previous geological mapping and geochemistry, we have an excellent technical base to start testing the numerous exploration targets in the district. Meanwhile, we continue to drill at Anzá and aim to release a new batch of drill results before the end of June.”

Peter Diorio, P. Geo., President of GeophysicsOne Inc. is the qualified person related to the helicopter magnetic and radiometric survey and has reviewed and verified the technical disclosure contained herein and accepts responsibility for such disclosure. David Makepeace, M.Eng., P.Eng., senior geologist for Micon International Limited is the qualified person for the Anzá drill program, as defined by National Instrument 43-101.

There has been insufficient exploration to define a mineral resource at the Anzá property to date, and it is uncertain if further exploration will result in targets being delineated as a mineral resource. Any potential quantity and grades are conceptual in nature.