Archive for category Airborne

Supervised Neural Network Targeting and Classification Analysis for Mineral Exploration

Posted by on Tuesday, 29 April, 2014
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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:  


World class geophysics for Republic of Kazakhstan

Posted by on Sunday, 6 April, 2014

April 3, 2014, Astana. Vice Minister of Industry and New Technologies of the Republic of Kazakhstan Nurlan Sauranbayev and Chairman of the Board of JSC “Kazgeologiya” Galim Nurzhanov met with the Ambassador of Canada Stephan Millar and leading world class Canadian geophysical companies Phoenix Geophysics and Geotech Ltd.

“I want to thank you for the meeting. I see great potential for fruitful cooperation in the field of exploration, “- said Stephen Millar. Vice Minister of Industry and New Technologies Nurlan Suranbaev suggested for further cooperation JSC “Kazgeologiya”, which held preliminary talks with the companies.

 

 

 

 

 

 


Recent investigations of geophysics abilities in aquifer mapping and resource evaluation

Posted by on Thursday, 13 March, 2014

Buried beneath the glaciated terrain, valleys filled with coarse-grained permeable sediments  potentially are great sources of fresh ground water. During the last several years Geological Survey of Canada has been investigating geophysical methods potential, particularly airborne electromagntics, for mapping and resource evaluation of buried valleys.   Spiritwood valley aquifer in southern Manitoba has been chosen for the investigations. Heliborne AeroTEM, VTEM, fixed-wing TEMPEST and MULTIPULSE, ground electrical resistivity and time-domain methods, seismic reflection and borehole data have been involved into the complex analysis. Recently collected ground TEM data for Spiritwood and the report (G.A. Oldenborger and K. Brewer, 2014) has been released: http://geoscan.nrcan.gc.ca/starweb/geoscan/servlet.starweb?path=geoscan/fulle.web&search1=R=293700.

One of the successful heliborne TEM examples (Legault, J.M., Prikhodko, A., Dodds, D.J., MacNae, J.C., Oldenborger, G.A., 2012. Results of recent VTEM helicopter system development testing over the Spiritwood Valley aquifer, Manitoba. Symposium on the Application of Geophysics to Environmental and Engineering Problems. Environmental and Engineering Geophysical Society, 114–130.):

VTEM-ground

 

 

 

 

 

 

 

 

 

 

 

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Another recent example of the results of a combined seismic and airborne electromagnetic (AEM) interpretation of the shallow Quaternary sedimentsand  bedrock but in British Columbia (Horn River Basin) was presented on Geoconvetion-2013  .

 

 


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


Linking Porphyry Deposit Geology to Geophysics via Physical Properties

Posted by on Tuesday, 7 January, 2014

Geoscience BC Releases the Report:

Linking Porphyry Deposit Geology to Geophysics via Physical Properties: Adding Value to Geoscience BC Geophysical Data
by Dianne Mitchinson, MDRU; R.J. Enkin, GSC; and C.J.R. Hart, MDRU.

Regional geophysical surveys were flown in 2007 and 2008 as part of the QUEST and QUEST-West projects to improve geological understanding in Quaternary sediment-covered areas and thereby encourage mineral exploration. As part of the ongoing process of adding value to Geoscience BC datasets, Project 2009-001, “Integrated Geological & Geophysical Porphyry Models: Adding Value to Geoscience BC Geophysical Data (NTS 93E, 93K, 93L, 93M, 93N)” was undertaken to define relationships between geophysical datasets collected as part of these QUEST surveys and porphyry deposit geology at six known porphyry deposits. The deposits chosen for investigation include: Mount Milligan, Endako, Huckleberry, Bell, Granisle and Morrison. 
Geoscience BC Report 2013-14 presents physical rock property data from the six above-listed BC porphyry deposits, and discusses observed trends within the detailed QUEST and QUEST-West geophysical datasets and mapped geology. The resulting physical rock property data compilation has implications for improving interpretations of geophysical data from porphyry deposits. A synopsis of physical property criteria defining hydrothermally altered or mineralized rocks in BC porphyry settings is provided, which can ultimately be used for ranking similar mineral exploration targets throughout BC, thereby minimizing exploration risk.

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Porphyry deposits surveyed during the QUEST and QUEST-West projects include Mount Milligan, Endako, Huckleberry, Bell, Granisle, and Morrison. Airborne magnetic and electromagnetic surveys (VTEM or AeroTEM) were conducted over each of these deposits. Additionally, a ZTEM (Z-axis tipper electromagnetic) survey was completed over the Mount Milligan deposit as a joint initiative between Geoscience BC and Terrane Metals Corp.

2009 : AeroTem Survey Results from the Equity Silver Mine
– Mineral Exploration Roundup Poster (pdf, 3.96MB)

Technical Article: 2009: “QUEST-West Geophysics in Central British Columbia (NTS 093E, F, G, K, L, M, N, 103I): New Regional Gravity and Helicopter-Borne Time-Domain Electromagnetic Data”
– Summary of Activities 2008, Report 2009-1 p.1-6 (pdf, 4.64MB)

 

 

 

 

 

Geophysical Surveys

 

 

Technical Article: 2007 : “Airborne electromagnetics and airborne gravity in the QUEST Project area, Williams Lake to Mackenzie, British Columbia (parts of NTS 093A, B, G, H, J, K, N, O; 094C, D)”
– Summary of Activities 2007, Report 2008-1 p.1-6 (pdf, 6.81MB)

Suggested Reference: Mitchinson, D.E., Enkin, R.J., and Hart, C.J.R. (2013): Linking Porphyry Deposit Geology to Geophysics via Physical Properties: Adding Value to Geoscience BC Geophysical Data; Geoscience BC, Report 2013-14, 116 p.

Report Components


Newmont and the NEWTEM experience

Posted by on Wednesday, 9 October, 2013
“Over the past two decades, the use of time-domain electromagnetic (EM) surveying systems, designed for an airborne helicopter-based platform, has risen in popularity. One of the first of these systems was developed and has been operated by Newmont Mining Corporation. The original system (NEWTEM I) and its more capable successor (NEWTEM II) were created to help our company explore for different types of mineral deposits, primarily gold bearing, as well as to provide general geologic mapping information in parts of the world that are often very difficult or expensive to explore otherwise.
The NEWTEM system has some characteristics that have proven to be advantageous in terms of safety, cost of operation, spatial resolution, and the ability to map effectively at both ends of the resistivity scale. Our approach to the acquisition, processing, and interpretation of airborne EM data is specific to this system and to the goals of our gold-focused exploration programs. Using what is most often a locally derived helicopter, we are able to carry out a survey of whatever size our exploration program dictates and on a schedule that meets our company’s needs. Results from NEWTEM surveys have been used to identify conductive and resistive targets but more importantly to advance our general understanding of an area’s potential to host mineralization of interest to this company. We intended to provide a brief written account of the NEWTEM story for the scientific and exploration communities, including information about its design and capabilities, as well as how we process this type of data. “

The technical program for SAGA-AEM Joint Conferences 2013

Posted by on Friday, 26 July, 2013

SAGA 13th biennial conference – 6th to 9th October 2013
6th International Airborne EM 2013 – 10th to 11th October 2013
Skukuza Rest Camp, Kruger National Park
Mpumalanga South Africa

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SAGA 2013 Conference Technical Programme

Click here to view the preliminary version of the SAGA 2013 Conference technical programme. A pdf version of the programme is also available for for viewing or download.

AEM 2013 Conference Technical Programme

Click here to view the preliminary version of the AEM 2013 Conference technical programme.pdf version of the programme is also available for for viewing or download.

Workshops and Short Courses

The workshop/tours list will be finalised end of July. Depending on registration numbers, some workshops will be cancelled and others will go ahead. Please register soon before end of July. Final workshop programme will be updated in August. The following workshops and short courses will be available during the conference. Download Workshops and Short Courses Information Pack.


VTEM09 VMS Prospect in Northern Ethiopia drilling results

Posted by on Tuesday, 23 July, 2013

Tigray Resources Inc. announces assay results from preliminary diamond drill-hole tests of the VTEM09 VMS Prospect on the Harvest Property and the Adi Gozomo Gold target on the Adyabo Project, in Northern Ethiopia. Single diamond drillholes tested both targets as an initial appraisal of prospectivity.

The results include:

  • 10.69 metres grading 3.47% copper, 4.2 grams per tonne gold, 3.69% zinc, and 91 grams per tonne silver from 19.81 metres, including 3.06 metres grading 5.75% copper, 8.00 grams per tonne gold, 0.70% zinc, and 107 grams per tonne silver (TVD001), at VTEM09
  • 7.5 metres grading 2.04 grams per tonne gold from 15.1m (AD001) at Adi Gozomo.

VTEM09 prospect

The high-grade copper and precious-metal enriched VMS mineralization intersected by TVD001 compares favourably with the metal tenor encountered at the Terakimti and Mayshehagne discoveries, and marks the third significant VMS discovery made at Harvest.

The VTEM09 prospect, located 5 kilometres ENE and along strike of Terakimti, was identified by an Airborne VTEM survey, and is characterized by a >200m strike length bedrock conductor. VTEM09 was further defined through mapping, soil sampling and trenching (refer to Tigray’s news release dated Jan 24th, 2013), and is interpreted to be a southwest-dipping, eastward-plunging mineralized VMS shoot. Additional drilling is required to test this prospect along strike, down dip and down plunge.

Adi Gozomo

One short diamond drillhole was targeted below the main artisanal workings, and encountered gold mineralization associated with the upper contact of a granodiorite hosted within mafic volcanic rocks. As the results to date indicate that gold mineralization appears directly proportional to the amount of pyrite present, additional ground exploration will be required prior to further drill testing at Adi Gozomo.

Diamond Drill Hole Results

DDH ID From (m) To (m) Interval (m)* Copper (%) Au (g/t) Ag (g/t) Zn (%) Prospect
TVD001 19.81 30.50 10.69 3.47 4.20 91 3.69 VTEM09
including 21.34 24.40 3.06 5.75 8.00 107 0.70
AD001 15.10 22.60 7.501 0.00 2.04 0 0.00 Adi Gozomo

* Intersection true widths are estimated at 60-90% of interval stated.

The Map


“the promise of airborne gravity gradiometry”

Posted by on Wednesday, 10 July, 2013

by DAN ZLOTNIKOV on JUNE 21, 2013 EXPERTISE

A versatile tool, airborne gravity gradiometry is changing the face of mineral exploration.

A relative newcomer to the resource exploration world, gravity gradiometry is already having a major impact. Its potential for producing high-quality data has caused many explorers to take notice and wonder how they might best make use of the technology.

See more at:


Airborne EM shows deep conductor extending to 1500 m depth

Posted by on Thursday, 20 June, 2013

Precious Metal Resources has opened up the potential for very deep mineralisation throughout its Halls Peak Base Metal Province in New South Wales, Australia) after reprocessing VTEM data.

The reprocessing by CD3D clearly demonstrated two electrically conductive beds with the deep bed, which had previously been mapped by electromagnetic surveys to depths of 400 metres, now interpreted as extending up to 1,500 metres deep.

Two examples of these beds are shown below:

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This deep bed does not crop out, and its nature is uncertain, as such conductive beds can be produced by several factors. These include sulphide mineralisation, which may include lead copper-silver sulphides, graphitic shales, magnetite bearing rocks.

Mapping to those depths strongly suggests continuity of the deep electrically conductive horizon between previously isolated districts, including the Long Point area, the Halls Peak area, and the Raspberry Road area.

Should this deep electrically conductive bed be produced by base metal mineralisation, the reinterpretation opens up potential for very extensive deep mineralisation throughout this province.

The shallow electrically conductive bed crops out in several places, where beds and pods of high-grade base metal mineralisation were mined within black shales

Past drilling and mining at Halls Peak has been too shallow to reach the potential high-grade lenses, instead intersecting either less mineralised beds within the overlying black shales, or high grade near surface mineralised fractures.

Screen dump of deep (500 mto 1000 m) conductance:

CD3D’s report states:

“Two extensive, sub-horizontal conductive bands were detected, one near surface and one mostly below 500 m. Map images of interval conductances are provided separately (“Stop50”), for the top 50 m and the 50 to 100m depth range, (“S50to100”), as well as for the 50 m to 500 m depth range, then for the 500 m to 1000 m range, and finally the 1000 m to 1500 m depth range. All the conductance maps have the same colour scale, with blue resistive and red conductive. A few conductive zones are fairly well imaged as seen in the following screen dumps.”

Details…


Airborne EM for VMS on ARMSTRONG BROOK PROJECT, NEW BRUNSWICK

Posted by on Friday, 31 May, 2013
The 2013 exploration program on the Armstrong Brook project commenced in early May. Highlights include the discovery of additional clusters of high-grade massive sulphide boulders in multiple locations (namely VMS Valley 4 & 5) and the completion of an airborne geophysical survey (VTEM) that identified intriguing anomalies in the vicinity of the primary boulder clusters.
The Armstrong Brook project comprises a number of high-grade polymetallic volcanogenic massive sulphide (VMS) prospects located in the Bathurst Mining Camp of northeastern New Brunswick, situated approximately 15 kilometres northwest of the Brunswick No. 12 Zn-Pb-Ag-Au deposit. Brunswick No. 12 is one of the world’s premier VMS deposits, having produced zinc, lead, silver and gold over a mine life of some 60 years.
VMS Valley 4:
The new discoveries at VMS Valley 4 occur as 2 boulder clusters located approximately 300 metres apart. Samples from the first cluster (AR13-0007-1 and 2) and the second cluster (AR13-0008-1 through 6), have returned high-grade mineralization with combined zinc+lead average assays of 13.68% and 10.33%, respectively, with impressive precious-metals as high as 459 grams per tonne silver and 1.07 grams per tonne gold. Complete assay results from the new boulder discoveries .
VMS Valley 5:
Additional prospecting has been completed in the vicinity of a recently discovered cluster of boulders located in the northwestern portion of the property. This work resulted in the discovery of 5 massive sulphide boulders in the vicinity of a discovery reported earlier in 2013, that yielded high-grade results with assays of up to 13.07% Zn, 6.07% Pb, 0.76% Cu, 251 g/t Ag and 0.66 g/t Au (see Wolfden news release dated March 20, 2013). These discoveries occur over an intermittent strike length of close to 700 metres and occur coincident to a significant geophysical anomaly that was identified in the recently completed VTEM airborne geophysical survey.
Assays remain pending for the new massive boulders from VMS Valley 5.
Preliminary results obtained from the VTEM survey indicate that the massive sulphide boulders are intimately associated with the eastern margin of a strong electromagnetic anomaly (EM conductor). This hook-shaped conductor attains a strike length of approximately 2 kilometres (see Image 1). Additionally, the cluster of massive sulphide boulders at VMS Valley 5 is centred within a broad circular-shaped magnetic high (total magnetic intensity) that has a radius of approximately 2.5 kilometres (see Image 2). Clearly, this anomaly requires detailed follow-up in the way of ground geophysical surveys prior to diamond drilling.

The 2013 exploration program on the Armstrong Brook project commenced in early May. Highlights include the discovery of additional clusters of high-grade massive sulphide boulders in multiple locations (namely VMS Valley 4 & 5) and the completion of an airborne geophysical survey (VTEM) that identified intriguing anomalies in the vicinity of the primary boulder clusters.The Armstrong Brook project comprises a number of high-grade polymetallic volcanogenic massive sulphide (VMS) prospects located in the Bathurst Mining Camp of northeastern New Brunswick, situated approximately 15 kilometres northwest of the Brunswick No. 12 Zn-Pb-Ag-Au deposit. Brunswick No. 12 is one of the world’s premier VMS deposits, having produced zinc, lead, silver and gold over a mine life of some 60 years.


The results of the EM/Magnetic airborne survey over the Borden Lake Extension

Posted by on Wednesday, 29 May, 2013

Nikos Explorations Ltd. announces the results of the high-resolution VTEM (Versatile Time-Domain Electromagnetic System) and magnetic airborne survey recently completed over the Borden Lake Extension by Geotech Ltd. A total of 391 line kilometers were flown to cover the Property. The VTEM and magnetic surveys were completed in order to identify electromagnetic and magnetic anomalies that may be associated with gold mineralization and to help in the geological interpretation of this underexplored area.

Results of the surveys indicate electromagnetic and/or magnetic anomalies in four areas of interest (see map at http://nikosexplorations.com/projects/borden_lake/) described below in order of priority for follow up:

1. Several magnetic lineaments, one of which is interpreted to be a fault, intersect near the boundaries of claims 4260529 and 4260530. Such lineaments can reflect structures that are known to be important in the transport of gold-rich fluids. A north-east south-west lineament, apparent on a shaded relief map of the region, also crosses the Nikos claims in this area giving further reason for follow up.

2. Cross cutting NNW-SSE and NE-SW trending positive magnetic anomalies in claim 4259808 may represent major structures. There are also coincident weak electromagnetic anomalies that could indicate the presence of sulphide.

3. Similar cross-cutting magnetic anomalies and electromagnetic anomalies seven to eight hundred metres east of 2, but not as strong.

4. This area in the east of the property is characterised by a small positive magnetic anomaly with a coincident electromagnetic anomaly.

Nikos is planning a follow up program of mapping, sampling and prospecting to investigate the cause of the anomalies.

The Borden Lake Extension Project is located near the town of Chapleau, Ontario in an area of good infrastructure including road, rail and power. It covers an area of 1,598 hectares immediately east of Probe Mine’s Borden Lake gold property where recent exploration has defined pit constrained indicated resources of 3,686,000 ounces of gold (112.8 M tonnes grading 1.02g/t gold) and inferred resources of 625,000 ounces of gold (18.04 M tonnes grading 1.08g/t gold) at a 0.5g/t cutoff grade. This is the first discovery of significant gold in the Kapuskasing Structural Zone.

The Borden Lake Extension property covers Archean aged metamorphic rocks in an underexplored portion of the Kapuskasing Structural Zone.

Nikos is planning an airbourne geophysical survey using VTEM (versatile time domain electromagnetics) and magnetics to explore for Borden Lake type gold mineralization. Gold at Borden Lake is associated with a continuous zone of disseminated sulphide (pyrite and pyrrhotite) mineralization that gives rise to electromagnetic anomalies. The airbourne survey is expected to be completed during the first quarter of 2013.


Airborne Geophysical Survey Along Trend Of The Alpha/Fission Patterson Lake Discovery

Posted by on Tuesday, 28 May, 2013

Forum Uranium Corp. announces the commencement of an electromagnetic and magnetic survey of its 100% owned Clearwater Project. Forum’s claims, staked immediately adjacent to the southwest of the Alpha Minerals/Fission Uranium claim boundary is interpreted to be on strike with the fertile conductive trend that hosts the high-grade uranium discovery on the Patterson Lake South project. Forum’s property lies only four kilometres southwest of the high grade boulder train on the Alpha/Fission property.

Figure shows historical electromagnetic trends, a magnetic map and lake sediment geochemical surveys in the Patterson Lake South area. The electromagnetic (EM) surveys stopped at Forum’s claim boundary, however EM conductors from these historic surveys trend in the direction of Forum’s ground. Of particular note is that the highest lake sediment value in the area lies on Forum’s southwest claim with a value of 8.3 ppm U. Most values are between 1 to 3 ppm U and the lake sediment sample taken down-ice from the Patterson lake boulder field was 3.2 ppm U.

An Aeroquest Airborne helicopter-borne time domain electromagnetic survey with Bfield-VTEM Plus and magnetic gradiometer system will be flown on 200 metre line spacings for a total of 647 line kilometres over Forum’s 99 square kilometre property. The VTEM Plus system has been chosen for its depth penetration and vertical/spatial resolution of graphitic conductors that are prospective hosts for unconformity-style uranium deposits.

This is the first phase of this year’s summer exploration program. Plans are to conduct an airborne radiometric survey and a detailed prospecting survey to search for any boulder fields similar to that found on the Alpha/Fission ground.


Graphite discoveries in Northeastern Ontario

Posted by on Thursday, 16 May, 2013

Zenyatta Ventures Ltd. announced a drilling update on the 100% owned Albany (Hydrothermal) Graphite Deposit, located in northeastern Ontario, Canada.

The first drill hole (Z13-4F10) intersected 363 metres (‘m’) of graphite mineralization from 47.0 m to 410.0 m.  This represents the widest zone of graphite material intersected to date on the Albany deposit.  The hole, which was drilled at a 180 azimuth and -65 dip, was designed to test between previously drilled holes 5 and 9.  From surface to 41.0 m hole 10 intersected overburden and from 41.0m to 47.0 m intersected Paleozoic limestone.  Graphitic overprinting was encountered from 47.0 m to 87.0 m, while the strongest graphitic mineralization was intersected from 87.0 m to 410.0 m. Drilling shows different types of graphite mineralization consisting of clasts of graphite vein material, disseminated graphite matrix and discrete graphite veins / veinlets as part of a large breccia pipe.  Geometry and true width of the graphite breccia pipe is difficult to determine at this point and will require much more drilling.

The Company will continue to define the size and grade of this rare, ‘vein-type’ or hydrothermal-style graphite deposit.  The goal of the current program will be to expand on a 2012 drilling campaign that intersected a large mineralized zone of graphitic breccia and veining from widely spaced drill holes.  This previous nine (9) hole drill program succeeded in establishing widespread graphite mineralization laterally for several hundred metres and to a vertical depth of 400m, where it remains open. The current drilling will consist of a minimum of 10,000m and will further test the extent of the Geotech VTEM airborne conductor. The program will require 40 holes and is expected to continue until August, after which a NI 43-101 resource estimate will be calculated. The Company anticipates a steady flow of information from drilling activities and continued metallurgical work from this fully funded $4 million exploration program for the balance of 2013.

14 May 2013

Zenyatta Ventures Ltd. announced the following significant assay results from the first hole (#10) of the current campaign on the 100% owned Albany (Hydrothermal) Graphite Deposit, located in northeastern Ontario, Canada.   Drill hole 10 intersected 360.8 metres (‘m’) of graphite mineralization from 49.0 m to 409.8 m yielding an average grade of 5.1% Carbon (‘C’).  This represents the widest zone of graphite material intersected to date on the Albany deposit.  The hole, which was drilled at a 180° azimuth and -65° dip, was designed to test between previously drilled holes 4, 5 and 9.  Five more holes have since been completed, all of which yielded broad intervals of graphite mineralization from visual observations of drill core as described below.  Holes 11 through 15 have been designed to start outside the limit of the indicated anomaly and were angled to help define and confirm the overall geometry of the pipe-like body.  Drill hole data from all 15 holes is shown in a table at the end of this press release.

• Drill hole 11 intersected 202.0 m of graphite mineralization from 393.0 m to 595.0 m.

• Drill hole 12 intersected 195.0 m of graphite mineralization from   90.0 m to 285.0 m.

• Drill hole 13 intersected 219.0 m of graphite mineralization from   96.0 m to 315.0 m.

• Drill hole 14 intersected 286.9 m of graphite mineralization from 108.8 m to 395.7 m and a second zone of 127.3 m of graphite mineralization from 431.3 m to 558.0 m

• Drill hole 15 intersected 301.9 m of graphite mineralization from   63.3 m to 365.2 m.   (All lengths reported are drill intersected core lengths and do not represent true widths)

Aubrey Eveleigh, President and CEO stated “These latest results confirm the exceptional size potential of the Albany graphite deposit and along with the previously announced ultra-high purity (>99.99% C) values, underpins Zenyatta’s extraordinary graphite project. Hole 10 represents the best grade drill intersection obtained to date and the more recent drill holes are confirming both the internal continuity and the extent of the deposit.”   Graphite mineralization appears to consist of graphitic breccia pipes which are typically surrounded by a zone of graphite overprinted syenite. Carbon analyses for drill holes 11 through 15 will be released once received.  Drill hole 16 has commenced, and the current campaign will continue until sufficient drill holes have been completed, following which a NI 43-101 compliant resource estimate will be prepared.  A plan map, section and drill hole table will be placed on the website today.

The Company has also completed a ground geophysical survey to better define the geometry of the Albany graphite breccia pipes and expects the full data to be released in the next few days once a final report has been completed by Crone Geophysics and Exploration Ltd. The survey has defined two adjacent, strongly conductive, geophysical (EM) anomalies that are roughly circular in shape.  Holes 10 through 15 were drilled on the eastern most anomaly (Eastern breccia pipe), and are suggesting an oval shaped body approximately 200 metres in a NW-SE long axis by approximately 125 metres NE-SW.  Additionally, hole 11 intersected mineralization at approximately 500 metres vertical depth.  Drill intercepts appear to be correlating well with the shape of the ground geophysical anomaly with additional drilling required to confirm this model. The western anomaly (Western breccia pipe), which appears to be larger, will also be fully tested during the current drill campaign.


Advances in Airborne and Ground Geophysical Methods for Uranium Exploration

Posted by on Tuesday, 30 April, 2013

IAEA (International Atomic Energy Agency) has published a book “Advances in Airborne and Ground Geophysical Methods for Uranium Exploration”.

“Due to growing global energy demand, many countries have seen a rise in uranium exploration activities in the past few years, and newly designed geophysical instruments and their application in uranium exploration are contributing to an increased probability of successful discoveries. This publication highlights advances in airborne and ground geophysical techniques and methods for uranium exploration, succinctly describing modern geophysical methods and demonstrating their application with examples.”

Download..


USGS: Iowa Meteorite Crater Confirmed

Posted by on Wednesday, 13 March, 2013

Recent airborne geophysical surveys near Decorah, Iowa are providing an unprecedented look at a 470- million-year-old meteorite crater concealed beneath bedrock and sediments.

The aerial surveys, a collaboration of the U.S. Geological Survey with the Iowa and Minnesota Geological Surveys, were conducted in the last 60 days to map geologic structures and assess the mineral and water resources of the region.

“Capturing images of an ancient meteorite impact was a huge bonus,” said Dr. Paul Bedrosian, a USGS geophysicist in Denver who is leading the effort to model the recently acquired geophysical data. “These findings highlight the range of applications that these geophysical methods can address.”

In 2008-09, geologists from the Iowa Department of Natural Resources’ (Iowa DNR) Iowa Geological and Water Survey hypothesized what has become known as the Decorah Impact Structure. The scientists examined water well drill-cuttings and recognized a unique shale unit preserved only beneath and near the city of Decorah. The extent of the shale, which was deposited after the impact by an ancient seaway, defines a “nice circular basin” of 5.5 km width, according to Robert McKay, a geologist at the Iowa Geological Survey.

Bevan French, a scientist the Smithsonian’s National Museum of Natural History, subsequently identified shocked quartz – considered strong evidence of an extra-terrestrial impact – in samples of sub-shale breccia from within the crater.

“The recognition of this buried geological structure was possible because of the collaboration of a local geologist, water well drillers, the USGS STATEMAP program, and the support of the Iowa DNR concerning research on fundamental aspects of Iowa geology,” said McKay.

The recent geophysical surveys include an airborne electromagnetic system, which is sensitive to how well rocks conduct electricity, and airborne gravity gradiometry, which measures subtle changes in rock density. The surveys both confirm the earlier work and provide a new view of the Decorah Impact Structure. Models of the electromagnetic data show a crater filled with electrically conductive shale and the underlying breccia, which is rock composed of broken fragments of rock cemented together by a fine-grained matrix.

“The shale is an ideal target and provides the electrical contrast that allows us to clearly image the geometry and internal structure of the crater,” Bedrosian said.

More analysis of the data will provide additional detail. These data show the impact as a nearly circular region distinct from the surrounding area to a depth of several hundred meters.

“These data, when coupled with physical property measurements on drill core samples, will form the basis for modeling efforts to constrain the impact geometry and energy of the meteorite,” said Dr. Andy Kass, a USGS geophysicist working on the effort.

The Iowa and Minnesota airborne geophysical surveys are targeting an igneous intrusion, known as the Northeast Iowa Igneous Intrusive complex, that may be similar to the Duluth layered igneous complex exposed in the Lake Superior region of northern Minnesota. Known copper, nickel, and platinum group metal resources were deposited during the formation of the Duluth complex. Both of these complexes are associated with a large structural feature known as the Midcontinent Rift, which is exposed in the Lake Superior Region but is covered by younger rocks as it extends to the south through Iowa, Nebraska, Kansas, and Missouri.

This geophysical survey is part of a larger USGS effort to evaluate the concealed mineral resource potential of the greater Midcontinent Rift region that formed about 1.1 billion years ago.

U.S. Department of the Interior, U.S. Geological Survey
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EMIT Maxwell Configuration File for VTEM system

Posted by on Sunday, 10 March, 2013

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