Posts Tagged spectrometry

Factors of Modern Discoveries

Posted by on Wednesday, 8 April, 2015
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“INTEGRATING NEW TECHNOLOGY WITH HISTORICAL DATA, GEOLOGICAL INTUITION AND A LITTLE LUCK, COMPANIES ARE FINDING SUCCESS WHERE OTHERS HAVE NOT”

E&MJ News

Mineral Exploration Strategies

E&MJ News published an article by Steve Fiscor where some factors of new mineral deposits discoveries have been outlined – these factors include applying modern geophysical technologies. The author provides some examples – airborne EM (VTEM, ZTEM), airborne gravity gradiometer, and airborne radiometric surveys which played key role in discoveries of mineral deposits.

“All of the discoveries were in the zone of other major discoveries, but most of them had been overlooked for one reason or another. The motivation could only be attributed to a geologically motivated hunch. New technology in the form of deep-penetrating airborne surveys allowed ground-based geophysical surveys to target undiscovered anomalies. Combining the new information with what they knew historically, exploration geologists were able to improve the drilling programs to quickly determine a resource.”

The next discoveries made with airborne geophysical technologies:

Albany Ultra-pure Graphite – VTEM survey

The Balboa Discovery at Cobre Panama – ZTEM survey

Kennady North Kimberlite Discoveries – airborne gravity gradiometer survey

PLS High Grade, High Techand Contrarian – airborne radiometric survey

Details..

 


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:  


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 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.


Airborne Magnetic and radiometric survey in Congo

Posted by on Monday, 23 April, 2012
Kilo Goldmines Ltd.  announces the following exploration update on its Somituri project:
Completion of an Airborne geophysical survey over the entire 122 square kilometre Exploitation Licence, that hosts the Adumbi gold deposit of the Somituri Project situated in Oriental Province of the Democratic Republic of Congo (“DRC”).
Completion of soil sampling and reconnaissance geological mapping on PE9692, PE138 and PE137
New Resolution Geophysics, based in South Africa, carried out an airborne Magnetic and Radiometric survey over PE9691, by helicopter, in mid April 2012. The survey consisted of 1,416.5 line kilometres flown at 100 metre intervals on a magnetic azimuth of 040° – 220° in order to orthogonally traverse the lithologies and gold bearing shear zones. The objective of the airborne geophysical is, in part, to better define the structural and lithological settings of the known gold deposits and gold occurrences hosted on the Exploitation Licence and the on-strike extensions of these structures in areas where they have not been exposed or exploited. In addition, the magnetics can determine the presence of younger intrusive rocks, and cross-cutting structures that are typically associated with shear hosted Archaean orogenic gold deposits as well as differentiate between the Banded Iron Formation (“BIF”), metasediments, volcanic and other rock types to complement geological mapping.
Airborne Magnetic and Radiometric survey was previously completed over PE 9692, PE 137, PE 138, PE 140, and 9695.
Since January the Company has completed soil sampling and reconnaissance geological mapping on PE9692, PE138 and PE137. Soil sampling and reconnaissance geological mapping is in progress on PE9695. The objective of this program is to delineate areas of anomalous gold values in soil, and ultimately define drill targets.
The Somituri Exploitation Licences are located in the Archaean Ngayu Greenstone Belt. Gold on PE 9691 (location of the Adumbi Deposit) is hosted within quartz veins in sheared Upper Kibalian formation comprised of a chemical metasedimentary unit that includes banded iron formation (“BIF”), tuffaceous metasedimentary rocks and greywacke. Similar rock types, as well as occurrences of massive haematite are present on 6 of the remaining PEs of the Somituri Project. One PE is underlain predominantly by basement orthogneiss and granites. The youngest lithology on the property is the Post Karoo, essentially a lateritic cuiriasse.
Also present within the Kibalian formation is quartzitic sandstone often with pyrite, pellitic and graphitic shales and horizons intercalated with fine quartzitic sandstone, banded sericite schists, quartz-sericite schists, phyllites, spotted schists and red banded shale. Gold bearing quartz veins are hosted within the Kibalian formation.

Exploration at Limão Gold Project in Brazil

Posted by on Tuesday, 17 January, 2012
Amerix Precious Metals Corporation reports that incoming results from its 2011 exploration program have outlined anomalous gold targets defined from geochemical surveys  that have been conducted across several grids established on the Company’s 10,000 hectare Limão Gold Property, located in the Tapajós District, Pará State, Brazil.
Amerix contracted Fugro Aviation of Brazil for an airborne magnetic and radiometric survey over its property as reported in News Release NR 2011 – 09. TerraNotes Ltd Geophysics of Toronto provided additional interpretive consultation of the airborne data.  New grids, existing grid extensions and infill lines have been completed as a continuation of Amerix’s 2009 and 2010 geochemical surveys, as well as over new, prospective areas identified from the airborne geophysical data. The geochemical grids cover an area of approximately 7.7 square kilometres of the approximate 100 square kilometre Limão property.  Grids were primarily sampled using a manual auger to take 1 metre deep samples at 20 metre spacing along the grid lines. Secondary, closer spaced grid lines and sampling was done over areas with anomalous geochemical results. Each grid line was mapped and every sample was geologically logged and then prepared for shipping and analysis. All samples were prepared at Acme Labs preparation facility in Itaituba, Brazil and samples were shipped to Acme’s Santiago, Chile Laboratory for fire assay gold analysis. The Company utilizes a QA/QC chain of custody program overseen by its geologists concerning its samples. Over 3,700 samples were taken during the 2011 program covering 4 principal grid areas and the geochemical results are presently being received by the Company in batches.
Complete results have been received for the South Grid geochemical survey and these are presented in the accompanying Figure 2. The South Grid covers 0.6 square kilometres and was established primarily to cover an area of past, small scale, informal mining. Importantly, the 2011 geochemical survey identified a significant soil anomaly at the South Grid. The anomaly is defined by greater than 20 ppb gold traceable for 350 metres along a 290 degree trend that is coincident with the old workings.
Company geologists have identified quartz veining occurring along easterly to westerly oriented, sheared contacts within predominantly granitic host rocks as exposed in a shaft and a cut face at the – 2 – workings. Rock sampling and geologic mapping in the immediate vicinity of these workings and along the coincident gold geochemical anomaly will continue in the early 2012 exploration program. Amerix anticipates that this target will be developed for drill testing in the upcoming 2012 drill campaign. A second gold in soil anomaly occurs in the east section of this grid area. This anomaly extends for approximately 250 metres in an easterly to westerly direction and is open to the east. Additional geochemical and rock sampling will be undertaken to define the extensions of this target. Several other minor anomalies also occur on the South Grid and may be the subject of further detailed survey work.
Complete results from geochemical analyses for the  other three grids are expected later in the first quarter. The Company will provide these results as it prepares for drilling that is anticipated to begin after the rainy season and later in the spring. Amerix is well funded to complete its first drill campaign at the Limão project, located in the historically gold rich Tapajós district of Brazil.

Airborne and Soil Samples Results – Yukon White Gold District

Posted by on Thursday, 5 January, 2012

The 2011 exploration program on Comstock’s QV Claims included 769 line-kilometre at 100 m spacing airborne magnetic and radiometric survey, reconnaissance ridge and spur soil surveys, and 100 m by 50 m grid soil surveys. Both airborne surveys and soil surveys have consistently identified two gold trends:

  • North-easterly trend measuring 2600 m long and open (QV grid)
  • North-westerly trend measuring 1530 m long and open (Stewart grid)

The QV and Stewart grids, in the southern part of the claim block, will be followed by trenching and a drill program in the summer of 2012. Gold values on the QV and Stewart grids run as high as 1030 ppb (1.03 g/t Au).

The reconnaissance survey in the northern part of the claim block has identified areas with gold anomalies to be followed by a detailed grid soil sampling in the summer of 2012. Gold values in the northern claim blocks run as high as 152 ppb, with co-incident pathfinder elements of As, Sb, Ba, and Hg.

Airborne Magnetics:

Precision Geophysics of Vancouver, BC, flew an airborne geophysics survey over the property in August 2011. The Company has received final results for the magnetic and radiometric surveys. Kaminak’s Coffee style intense magnetic lows, interpreted as structures trending in both north-westerly and north-easterly directions, have been identified from the geophysics survey. Both magnetic lows and magnetic highs align with the gold-in-soil geochemical trend. The Company is very encouraged by the results of the airborne geophysics survey. Please refer to the Company’s website http://www.comstock-metals.com/projects/white_gold_north/ for maps showing geophysical results.

Airborne Geophysical Program:

Precision Geophysics of Vancouver, BC, flew an airborne geophysics survey consisting of 769 line-kilometres at 100 m line spacing over the property in August 2011. This survey collected both magnetic and radiometric data that will help the Company interpret the regional geology and structure of the area. Intense magnetic lows, interpreted as structures trending in both north-westerly and north-easterly directions, have been identified from this geophysics survey. This response is similar to that encountered at Kaminak’s Coffee property. Both magnetic lows and magnetic highs align with the gold-in-soil geochemical trend.

Soil Geochem:

The Company has received results for the final batch of soil assays with values ranging up to 1,030 ppb gold (1.03 g/t Au). The grid soil geochem surveys have identified two obvious gold trends supported by very strong pathfinder elements, found in association with gold systems in general and in the White Gold District in particular. These pathfinder elements include As, Sb, Ba, and Hg. Two trends have been identified through the detailed grid (100 m by 50 m) soil sampling.


Magnetic and radiometric survey in Colombia

Posted by on Thursday, 27 October, 2011

CuOro Resources Corp. announces that it has received the final data, maps, and report on the airborne magnetometer and radiometric survey which was conducted by MPX Geophysics Ltd (“MPX”) over the Company’s 100% owned Santa Elena Project, located in the Department of Antioquia, Colombia.

Highlights Include:

  • A large magnetic feature over 1km in length over the outcrops in the current exploration area
  • A new large 1km by 500m intense magnetic anomaly in the southwest corner of the property several kilometers from the current exploration area
  • Several smaller yet intensely magnetic bodies have been mapped on the Company’s northern concession

The airborne magnetometer and radiometric survey was flown with a helicopter and covered the entire 1287.5 hectare project area. Lines were orientated east-west and flown at a 50 meter line spacing with north-south tie lines every 500 meters. A total of352 line-kilometers of data were collected.

The objectives of the airborne magnetic and radiometric survey were to provide information to facilitate geological mapping and to assist in the delineation of target areas for future ground geophysical surveys and guide the current diamond drilling program. Prioritization will be the interpretation of anomalies which may represent massive sulphide mineralization.

VMS deposits typically contain pyrrhotite, an iron sulphide that is magnetic and can be detected by magnetometer surveys. Tests by Company geologists confirm the presence of pyrrhotite within the massive sulphides at Santa Elena.

Within the current area of exploration a large magnetic feature has been delineated from the southern most massive sulphide outcrops to the northern most edge of the Santa Elena Property. The magnetic feature is over a kilometer in length and is on strike with the existing massive sulphide outcrops.

A large highly intense magnetic anomaly has been mapped on the southwest corner of the property several kilometers from the current area of exploration. This magnetic feature is approximately one kilometer in length and five hundred meters in width. It is unknown whether this magnetic anomaly is part of a larger magnetic body, or if it is an independent geological feature. This anomaly warrants further investigation, and field crews will be deployed to this area immediately. No prior exploration or field mapping has been conducted in this area however recent work has discovered two new massive sulphide outcrops that are currently being channel sampled.

Several smaller yet intensely magnetic bodies have been mapped on the Company’s northern concession. These anomalies will be targeted for field exploration.

This data – used in combination with the recently completed phase one IP and resistivity survey -will greatly enhance the Company’s interpretation and understanding of the regional geology and structural system within the Santa Elena Project area, along with the identification of additional drill target areas.

Santa Elena is classified as Porphyry and poly-metallic deposits project containing 1,287.5 hectares near the north end of the Antioquia batholiths, in sequence of Cretaceous marine sediments and basaltic volcanic. Contains a large stockwork system, with an iron cap on top of the massive sulphide outcrops (Gossan) which potentially indicates an underlying porphyry system. Excellent infrastructure including paved road access, two hydroelectric plants within 5 km, and abundant water supply. Geological mapping and sampling has identified 2 VMS areas of outcropping (Azufral & Arroyo), and gossans. Ground geophysics has identified 4 strong conductors with good vertical extent, 2 of which are coincident with the Azufral & Arroyo outcrops. Artisanal underground workings exposed mineralized, sheared and brecciated mineralization with up to 2. 50% sulphides, from 0.5% to +2% Cu & from 0.2% to +1% Zn.


Radiometric and magnetic survey for REE

Posted by on Saturday, 15 October, 2011

Arctic Star Exploration Corp. announces that Aeroquest International Ltd. has completed airborne magnetic and radiometric surveys on three properties located in the Carbo area of ‘The Rocky Mountain Rare Metal Belt’ of northern British Columbia.

The Cap, Seebach and Javorsky rare earth element (“REE”) and rare metal properties are all located within the immediate vicinity of Spectrum Mining Corporation’s Wicheeda REE Discovery as well as the Carbo Project which has been drilled by Canadian International Minerals Inc. Arctic Star is conducting exploration under its option to earn up to 100% interest in these properties. The group of claims are located 80 km northeast of Prince George and together comprises 20 mineral claims covering approximately 9,129 hectares, making it one of the largest land positions in the camp.

The heli-borne AeroMAG magnetic gradient and radiometric survey consisted of approximately 1,500 line kilometres on the three properties. The preliminary results of the survey have identified several radiometric anomalies on the Cap property, which are considered to be high priority with respect to the other surveyed properties in the Carbo area. The magnetic component of the survey further defined the strong magnetic anomaly as previously defined by the regional magnetic survey.

The preliminary results of the airborne survey, in combination with the 2010 prospecting program which located outcrops of syenite with anomalous values of Nb and Zr (see November 17th News Release) are very encouraging. In the Carbo area, syenite is often found in close proximity to REE bearing carbonatite.

A detailed mapping and prospecting program, in combination with soil sampling has commenced on the Cap Property in order to verify the geophysical anomalies and define drill targets.

Publicly available records show that the nearby Wicheeda REE Discovery owned by Spectrum Mining showed encouraging results for REE in 2008 and 2009 drilling.

Source: http://www.marketwire.com/press-release/Arctic-Star-Exploration-Corp-Announces-Airborne-Surveys-Completed-TSX-V-ADD-1573392.htm


New Geophysical Target Zones in Aurora Region, Guyana

Posted by on Tuesday, 4 October, 2011

GMV Minerals Inc. announces that it has received further detailed airborne magnetic and gamma-ray spectrometry survey data. The new data covers GMV’s Aurora claims in Guyana.

The airborne survey was comprised of 5,100 line-kilometres of magnetics and gamma-ray spectrometry. Enhancement filters applied to the magnetics have highlighted a number of dominant structural orientations and trends. Definite ‘breaks’ in the predominate WNW fabric are shown by the magnetics and identified as target areas of interest. These cross-trends provide potential for significant fracturing and mobilization of mineralized fluids such as gold.

Eight target zones of structural complexity are identified from the magnetic analysis. These prospective areas are based on inferred structural complexity being immediately adjacent to and within regions of major shear zones (magnetic discontinuity). Gold mineralization is known to commonly occur near major crustal breaks manifesting as large-scale shear zones, which act as conduits for mineralizing fluids. Mineralization therefore may occur in regions of structural complexity adjacent to the shear zones.

GMV’s Aurora block lies directly south of Guyana Goldfields Inc.’s  property and is situated as the only major landholding between Guyana Goldfields’ Aurora (6.9m ounces gold) deposit and Sandspring’s Toroparu (8.4m ounces gold) deposit. Both of these deposits are in similar geology to that found on the GMV claims. The Aurora block and regional area presently are being worked for alluvial gold and have numerous historic workings in the area. Local access roads are presently being constructed as well the main roads to both deposits are being improved.

Anomalous potassium concentrations are mapped by the gamma-ray spectrometry as ‘ringing’ a magnetically-positive and anomalous Trans-Amazonian tectno-thermal granitoid inferred to occur in the northern half of the study area. These high potassium readings occur within otherwise potassium-poor rocks along or adjacent to inferred (magnetics) fault/shear zones and may therefore indicate anomalous sericite alteration. A significant correlation of low eTh/K ratio occurs in the northeast part of the survey block, in conjunction to the strongest zone of structural complexity interpreted from the magnetics. As thorium enrichment generally does not accompany potassium during hydrothermal alteration processes, eTh/K ratios often provide excellent distinction between potassium associated with alteration and anomalies related to normal lithological variations.

Airborne gamma-ray spectrometry surveys can be of direct assistance to exploration either because one or more of the radioelements is an associated trace constituent or because the mineralizing process has changed the radioelement ratios in the surrounding environment. Work completed to date on GMV ground and correlations to known mineral occurrences elsewhere in northern Guyana suggests that this ancillary data is providing key information to the current exploration programmes.

Douglas Perkins, GMV’s VP Exploration remarked, “This is truly one of the most exciting areas to test in GMV’s 1000 sq. mile land package. This new information has confirmed that we have the right ground not only from the proximity to significant defined gold deposits with similar geology but also by the anomalies indicated by the airborne survey and the presence of alluvial gold in the area.”

A program of geological prospecting, sampling and ground geophysics consisting of detailed magnetics and 3D induced polarization / resistivity is planned to further delineate the conductive zones and possibly identify disseminated sulphides which in turn could indicate anomalous gold mineralization.


Complex airborne survey in Suriname

Posted by on Wednesday, 28 September, 2011

Hunter Bay Minerals plc  announces the completion of its airborne geophysical survey at its Sela Creek Project, Suriname. The 4,986 kilometre aeromagnetic, radiometric and XDS VLF-EM survey was conducted by Terraquest Ltd. and indicates that areas of known mineralization are coincident with magnetic and radiometric anomalism. Using this geophysical signature and first pass field work, Hunter Bay has identified three high priority targets for immediate follow up work: Central Ridge, Jons Pit-Texas trend and Eastern Anomaly.

Aeromagnetic data (Figure 1) indicates that the broad area containing the three high priority targets occurs within a regional scale, rhombic dilational structure approximately 20 kilometres long and up to 8 kilometres wide, bounded to the north and south by west-northwest trending shear zones. Preliminary interpretation, combined with field observations from limited outcrop, suggests that the mid-range subdued magnetic response within the rhombic structure is associated with deeply weathered metasedimentary rocks intruded by dioritic, granodioritic and tonalitic intrusions.

Many of the known saprolitic workings occur either at the inferred contacts between metasedimentary rocks and intrusive bodies or cluster along a 5 kilometre, northwest trending structure called the Jons Pit-Texas trend. These observations highlight the importance of intrusion-related targets at Sela Creek and the structural controls on mineralization. In detail mineralization is spatially related to localized magnetic lows and coincident high potassium radiometric anomalies, which are interpreted to represent areas of hydrothermal alteration (Figure 2).

Central Ridge is a 2 kilometre long, east-west trending magnetic low bounded by moderate intensity magnetic highs, located immediately northwest of the Jons Pit-Texas trend. This magnetic anomaly coincides with a 5 kilometre long, east-west trending ridge which forms the watershed between several prominent north and south draining creek systems. These creeks have been extensively mined for alluvial gold. Central Ridge represents a high priority target for follow-up soil sampling and mapping.

Eastern Anomaly is a new high priority target in the eastern part of the licence. Eastern Anomaly comprises a 2 kilometre long, northeast trending magnetic low and coincident potassium high, which is a similar geophysical signature to that observed at the Jons Pit-Texas trend.

In conjunction with the Terraquest airborne survey, Hunter Bay also conducted aerial reconnaissance using a Cessna light aircraft which has provided a better understanding of the spatial extent of mineralization defined by artisenal workings in saprolite. In particular, shear-hosted and structurally-controlled mineralization is more extensive than previously mapped and in some places artisenal workings define up to 3 sub-parallel mineralized zones with a combined surface expression of up to 100 metres wide and over 1 kilometre long (Figure 3). Collectively artisenal workings define a broadly northwest trending corridor approximately 5 kilometres long and 1.5 kilometres wide (Jons Pit-Texas trend). Small areas of artisenal working are also present in the north and west of the licence and represent new showings which had not been previously identified.

Hunter Bay is presently completing additional processing and more detailed interpretation of the geophysical data in order to further identify and prioritize geophysical targets. An extensive soil sampling and follow-up mapping program is to commence in July 2011. Data collected during this stage of the program will be used to plan a reconnaissance drilling program.

To view the three images associated with this release, please click the following link: http://media3.marketwire.com/docs/HBYmaps.pdf.


Airborne geophysics over the Symphony Property

Posted by on Thursday, 22 September, 2011

BonTerra Resources Inc. Fugro Airborne Surveys has commenced an aeroelectromagnetic survey over the entire Symphony Property (the “Property”). The Property is situated in the Omineca mining division approximately 29 kilometres southwest of Houston, British Columbia.  BonTerra recently staked additional claims to consolidate its land position situated in between the Silver Queen Mine to the south and the Silver Streak property to the north.

Directly bordering the Property to the south is the past producing Silver Queen Mine. Historical ore grades are 8.72 opt (299 grams / tonne) silver, 0.18 opt (6.17 g/t) gold, 6.73% zinc, 1.16% lead, and 0.47% copper.

The Silver Queen property is currently being advanced by New Nadina Explorations. New Nadina has intersected silver, gold and base metal mineralization on the property. They have completed an aeromagnetic and ZTEM survey, a titan geophysical survey and diamond drilling. Drilling revealed grades of up to 493.5 g/t silver, 5.06 g/t gold, 13.5% zinc, 6% lead and 2.88% copper. The mineralized trend has a general southeast to northwest trend, the direction towards which the Property is situated.

General Location Map:

http://www.bonterraresources.com/i/pdf/SymphLocationMap.pdf

The Silver Streak property is situated to the north of the Property. Trenching on the Silver Streak identified significant mineralization which included 1.99% Cu and 338 g/t Ag over 33 meters. An inclined diamond drill hole was drilled underneath this trench in 1991. A zone grading 8.8 meters of 0.49% copper and 258 g/t silver, within 21.1 meters averaging 0.27% copper and 127 g/t silver was discovered. Another trench excavated in 2002 graded 0.26% copper and 1.91 g/t Ag over 16.7 meters. The mineralized zone is believed to have a NW-SE strike, the general direction of the Property.

This DIGHEM Electromagnetic survey with optional Radiometrics will total 308 line kilometres of readings. DIGHEM records electromagnetic data which can be interpreted to show changes in bedrock geology to great depth. The system uses multiple frequency electromagnetic fields to measure and map electrical conductivity in three dimensions. The DIGHEM EM system provides the interpretation benefits that can only be realized by a system employing both horizontal coplanar and vertical coaxial transmitter-receiver coil-pairs. BonTerra has selected Fugro’s optional Radiometrics application for an effective geological mapping solution as part of this mineral exploration program. The Company plans on using this survey to identify additional targets of interest on the property in its evaluation for silver and base metal mineralization potential on the Property.


AIRBORNE SURVEYS OVER BC RARE EARTH PROSPECTS

Posted by on Friday, 9 September, 2011

MONTORO RETAINS AEROQUEST FOR AIRBORNE SURVEYS OVER BC RARE EARTH PROSPECTS

International Montoro Resources Inc. has retained Aeroquest International Limited to conduct multiple large scale geophysical and radiometric airborne surveys over the highly prospective “Tacheeda NW” and “Chuchinka NW” Rare Earth Element prospects located in ‘The Rocky Mountain Rare Metal Belt’of northern British Columbia. Both of Montoro’s newly acquired properties are on trend with properties held by Spectrum Mining Corp. (the “Wicheeda” discovery), who announced a 48.64 metre interval which averaged 3.55% REE, a 72.0 metre interval that averaged 2.92% REE, and a 144 metre interval which averaged 2.20% REE in three separate drill holes.

These airborne surveys will assist in identifying and prioritizing Rare Earth Element drill targets for multiple planned upcoming drill programs. The surveys will consist of approx. 1400 line kilometres and will be flown at 50 metre line spacing. The AeroMAG (Gradient & Radiometrics) system is ideal for its superior ability to contour in northern BC’s rugged terrain.

Montoro’s President and CEO, Gary Musil, stated “Several significant anomalies have been discovered on our Chuchinka REE property, using airborne geophysical surveys. Our upcoming 2011 surveys will encompass the newly acquired Tacheeda NW and Chuchinka NW claims. The previous airborne surveys conducted in the area by numerous other companies (ie. Bolero Resources Corp., Canadian International Minerals Inc., Commerce Resources Corp., and Electric Metals Inc.) have all discovered numerous anomalies that have encouraged further advancing those projects into successful sampling and drilling programs, as well as additional discoveries of REE zones”.

Phase 2 exploration at the “Chuchinka” REE property is now underway and will be focused on defining priority drill targets within several anomalies discovered by joint venture partner, Electric Metals Inc. (EMI – TSX.V) through an airborne geophysical survey in 2010. The largest of these targets, measuring over 4 km by 1 km, is located near the centre of the property and is defined by a broad magnetic low associated with coincident conductive anomalies. Geochemical sampling of soils and bedrock, together with ground-based geophysics in the form of precision magnetometer and scintillometer surveying, are being applied to identify the most prospective portions of this and other REE targets in preparation for drilling.


Airborne Geophysics Survey Completed in the White Gold District of Yukon

Posted by on Saturday, 13 August, 2011

Smash Minerals Corp. is undertaking a vigorous exploration program on its Whiskey Gold Property, located in the White Gold District of west-central Yukon Territory, Canada. The property occupies 4,177 claims covering an area of 846 square kilometres including the placer gold-rich Black Hills and Barker creeks, and is east of and contiguous with claims formally held by Underworld Resources Corp. and now Kinross Gold Corp.

Aeromagnetic / Radiometric Survey

A property-wide 10,616 line-kilometre magnetic and radiometric helicopter geophysical survey at 100 metre line spacing was completed at the end of July. Final magnetic products have been received from the contractor Precision Geosurveys. Preliminary radiometric products have been supplied, and final processing will be completed within the next month. Geological interpretation of this data by the project team has identified a number of regional-scale east-west and north-northwest trending structures. Several intersections of these structures coincide with multi-element geochemical anomalies defined by ridge and grid soil sampling and rock grab sampling. The geophysical data have also been used to refine lithologic contact locations and outline zones of hydrothermal alteration.


EXPLORATION AT CHUCHINKA REE-CARBONATITE PROPERTY

Posted by on Sunday, 26 June, 2011

ELECTRIC METALS INC. and Montoro Resources Inc announce it has commenced exploration on the Chuchinka REE-Carbonatite property, located in the Wicheeda-Carbo district north of Prince George, British Columbia.

Phase 1 exploration has commenced to define drill targets within several anomalies discovered by Electric Metals with an airborne geophysical survey in 2010 (Aeroquest). The largest of these targets, measuring over 4 km by 1 km, is located near the centre of the property and is defined by a broad magnetic low associated with coincident conductive anomalies. Geochemical sampling of soils and bedrock, together with ground-based geophysics in the form of precision magnetometer and scintillometer surveying, are being applied to identify the most prospective portions of this and other targets.

Phase 2 exploration consisting of trenching and drilling will follow upon receipt of results of the Phase 1 program.


Geophysical survey over Tassawini Gold Project area (Guyana)

Posted by on Tuesday, 26 April, 2011
Takara  Resources Inc. announces that  geophysical survey over its Tassawini Gold Project area, located in the north-west region of Guyana, South America. The survey is expected to begin in the next two weeks and is scheduled to be completed over a two to four week period, weather permitting.
Jennifer Boyle, President and CEO of Takara Resources commented: “The results from the airborne geophysics, combined with the structural mapping  that is scheduled to take place in June, will give us improved confidence in drill target selection for the upcoming 2011 diamond drilling campaign. Our objective is to identify additional satellite deposits  in proximity to the Tassawini deposit in  anticipation that  new mineralized zones can be incorporated into an inhouse scoping  report and  subsequent independent  feasibility study, which is expected to begin before the end of the second quarter of 2011”.
The survey is planned at 50 meter spacing on North – South traverse lines, and 500 meter spacing along East – West tie lines (normal to flight-line direction).
Geotech is recognized as a leading geophysical company having significant experience  in Guyana, South America. The geophysical team has been conducting airborne surveys for nearly 30 years on a world-wide basis including over  rainforest in saprolite and laterite terrain in the Guyana Shield. Resulting data from the airborne magnetics and radiometrics survey is expected to facilitate geologic mapping, particularly structural and alteration patterns related to  gold mineralization.
Tassawini is an advanced stage gold exploration property centered on the site of the former producing Tassawini Gold Mine where, between 1907 and 1914, an estimated 11,200 ounces of gold was recovered. Prior to the acquisition by Takara, this property was subject to extensive exploration by the prior owner, StrataGold Corporation, who incurred approximately US$25 million in exploration expenditures and completed a resource estimate with SRK Consulting (Canada) Inc. of 499,000 ounces grading 1.3 g/t (437,000 ounces gold (indicated) and 62,000 ounces gold (inferred) in the Tassawini and Sonne Deposits).