Posts Tagged DC Resistivity

IP Survey Expands Potential of Schaft Creek Deposit

Posted by AP on Monday, 16 August, 2010

Copper Fox Metals Inc.  provides an update on the results and interpretation of the Quantec Geosciences Ltd. “State of the Art” Quantec Titan-24 DCIP and MT geophysical survey, on the Schaft Creek copper-gold-molybdenum-silver deposit located in Northwest British Columbia.

Highlights:

  • the Induced Polarization/Resistivity (IP) anomalies outlined by the Survey strongly suggest that the Schaft Creek mineral deposit extends a significant distance to the east and at depth beyond the limits of the current diamond drilling,
  • the Survey indicates that the IP anomalies that correspond to the Main, Paramount and Breccia Zones of the Schaft Creek mineral deposit are open to the north and south, and
  • the Induced Polarization anomalies outlined in 2008 have been confirmed by the Survey but these responses are interpreted to represent a geological feature, not mineralization.

Mr. Elmer Stewart, President of Copper Fox stated that “Our primary objective is to complete the feasibility study by the end of 2010. If the IP anomalies are an indication of the size of the Schaft Creek deposit, then the deposit is substantially larger than what has been defined to date. A substantial amount of diamond drilling would be required to define the limits of the deposit. Our 2010 diamond drilling program; although not designed for exploration has been adjusted to test the large IP anomaly identified on Section 6361000 under Mount LaCasse”.

Schaft Creek Deposit:
The Schaft Creek mineral deposit consists of three mineralized zones, being the Main, West Breccia and Paramount (see About Copper Fox for resource estimate of the Schaft Creek deposit).

Quantec Titan-24 DCIP and MT Survey:
Quantec Geosciences Limited (Quantec) was retained to further define two Induced Polarization anomalies located in the area of the proposed mill site in 2008. In order to better interpret any anomalies located by the Survey, the scope of the Survey was extended to include the portions of the Schaft Creek deposit where diamond drilling had been completed. The lithologies, sulphide content and metal grades obtained from the diamond drilling completed on the geophysical Sections were used in the interpretation of the geophysical responses obtained by the Survey.

A comparison of the geophysical response for the Null referenced, DC referenced, Resistivity and MT pseudo-sections shows excellent correlation. To view a geophysical model of the Schaft Creek mineral deposit based on the Null reference chargeability click here. A brief discussion of the IP anomalies defined on each Section is presented below:

Section 6361000:
The survey on this line was completed as a west and east portion due to hazardous terrain conditions. On the west side of the line, the IP anomaly is approximately 1,200 m wide and extends to a depth of 750 m. The western 400 m wide portion of this anomaly corresponds to the Paramount/West Breccia Zone where significant copper-molybdenum-gold-silver mineralization has been defined to an average depth of 400 m below surface. The 800 m wide portion of the IP anomaly located east of the Paramount/West Breccia Zone dips to the east under Mount LaCasse, is open at depth and requires testing by diamond drilling.

The east side of Section 6361000 covers the area of the proposed mill site where the two IP anomalies were located in 2008. The Quantec Survey located the 2008 IP anomalies and based on the diamond drilling information and the strength of the geophysical response, these anomalies are interpreted to represent a geological feature, not sulphide mineralization.

Section 6360600:
The IP anomaly is 1,500 m wide and extends to a depth of at least 750 m below surface. The western 550 m wide portion of this anomaly corresponds to the Paramount/West Breccia Zone where copper-molybdenum-gold-silver mineralization has been drilled to an average depth of 500 m below surface. The 850 m wide portion of this IP anomaly located east of the Paramount/West Breccia Zone dips to the east under Mount LaCasse and requires testing by diamond drilling.

Section 6360200:
The IP anomaly is 1,600 m wide and extends to a depth of 800 m at the center of the anomaly. This anomaly corresponds to the Main and West Breccia Zones where significant copper-molybdenum-gold-silver mineralization and has been intersected by drilling to an average depth of 500 metres below surface. The IP anomaly indicates that copper-molybdenum-gold-silver mineralization extend to a considerable depth below the 500 metre level. A 500 m wide portion of this anomaly located east of the Main Zone requires testing by diamond drilling.

Section 6350800:
Two IP anomalies have been located on this Section. The first anomaly is approximately 250 m wide, has a depth of 300 m and requires testing by diamond drilling. The second IP anomaly is 1,450 m wide; has a depth of approximately 600 m on the western side and a depth of 450 m on the east side. The IP anomaly corresponds to the Main and West Breccia Zones where significant copper-molybdenum-gold-silver mineralization has been drilled to a depth of 250 m. The portion of the IP anomaly below the 250 m level requires testing by diamond drilling.

Section 6350400:
The IP anomaly is 1,500 m wide and has an average thickness of 400 m. The western portion of this anomaly measures 300 m wide by 450 m deep and is located at a depth of 200 m below surface (interpreted to be faulted downward). The remaining 1,200 m wide portion of the anomaly is relatively flat lying and has an average depth of approximately 400 m. This anomaly corresponds to the Main and West Breccia Zones where significant copper-molybdenum-gold-silver mineralization has been drilled to a depth of 250 m below surface. A 250 m wide section on the east side of this anomaly requires testing by diamond drilling. The IP anomaly is open along strike to the south.

Quantec Titan-24 Survey Parameters:
The Quantec Titan-24 DCIP and MT system is a State of the Art geophysical tool used to explore forcopper mineralization. The Survey was completed on five lines surveyed by differential GPS instrumentation over the area of the proposed mill site and further to the west over the Schaft Creek deposit where a substantial amount of diamond drilling had been completed. Survey Sections were completed at 100 m station intervals and 400 metre line spacing. A total of 28.2 kms of DC/IP survey line (plus current extensions) and 22 kms of MT data were collected. Magnetotelluric, Resistivity and Chargeability data were collected at 50 metres stations along each Section. The Titan-24 survey typically images DC resistivity to depths of 500-750 m and the IP typically images to 500-750 m, in sub-vertical tabular geologic settings and up to 50% more for sub-horizontal settings. The interpretation of the data was completed by Quantec utilizing the lithology, estimated sulphide content and analytical results from the diamond drill holes completed on or near the geophysical Sections. The 3D inversion of the DC and IP data was completed using the UBC3D inversion code and is shown as Null referenced and DC referenced chargeability. In several cases, not all of the line could be surveyed due to hazardous terrain conditions. The 14 mRad contour on the UBC smoothed, Null Referenced pseudo-section was used to determine anomalous chargeability.


Titan Uranium for testing geophysical signs

Posted by AP on Monday, 26 July, 2010

Rodney Koch, P. Geo, Vice-President Exploration Canada for Titan and geophysicist with rich experience in Athabasca basin has announced the new drill program on the Border Block project which is located in the southwest area of the Athabasca Basin, near the Alberta border.

The planned program consists of approximately 1,500 metres of diamond drilling to test prospective targets identified by recently completed (Spring 2010) SQUID Time Domain ElectroMagnetic (TDEM) and D.C. Resistivity surveys. D.C. Resistivity is the geophysical technique of choice in the Athabasca Basin due to its ability to image hydrothermal alteration systems, which form resistivity “chimneys”, often associated with fault zones and unconformity-type uranium deposits. The project (76,354 hectares/188,675 acres) covers an area where historic exploration data identified favourable basement rocks capable of hosting uranium mineralization.


Li3 Energy Geophysical Study

Posted by AP on Thursday, 24 June, 2010

Li3 Energy, Inc. announce the successful completion of a geophysical orientation profile on its Pocitos Property. The survey identified three unique geophysical target areas, with potential to host mineral rich (lithium, potassium magnesium etc) brine aquifers.

Five geophysical data recording stations were established at 2 kilometer intervals along a 10 kilometer long orientation line (line 74-84). Geophysical data show that the Salar is up to 550 meters deep and that three distinct areas were outlined by electrical properties that measure the ability of each area to act as an aquifer. Generally, stronger electrical responses indicate a higher probability that the area contains mineral rich brines.

Three target areas (“Target Areas 1, 2 and 3”) have been identified and prioritized as follows:

The geophysical response (resistivity averages 0.2 ohm meters) indicates that this unit has a high probability of containing mineral rich brine aquifers. NOTE: The lower the resistivity of the target unit the higher the probability that the target unit contains mineral rich brine aquifers.

The geophysical response (resistivity ranges from 0.4 to 0.6 ohm meters) is very significant and suggests this unit contains multiple thin mineral rich aquifers distributed through the unit. Notwithstanding the very encouraging diagnostic result there is insufficient data at this time to estimate a brine resource.

“The results of this geophysical orientation test are very exciting because they suggests that this method will be a valuable exploration tool for identifying mineral rich brine aquifers” reports Mr. Luis Saenz, CEO of Li3.

Geophysical Instrumentation used during the Orientation Survey:

The orientation survey was carried out by the professionals of the Applied Geophysics Group (“GEOFI”), Institute of Petroleum and Natural Reservoirs of Directorate of Technical Studies and Research, Faculty of Engineering, National University, De Cuyo Cuyo, Mendoza, Argentina.

The ARREESS Automatic Resistivity system used for the orientation survey is a state of the art resistivity system with up to 10 adjustable IP windows and 2D and 3D Resistivity tomography capabilities using multi –electrode arrays. The transmitting power is up to 300 Watts, Current is up to 2.0 Amp and the Voltage ranges from 10 to 550. The precision is rated at 0.5%. Significant features of this powerful system include a self-adapting control system, automatic ranging and calibration, automatic checking of measured value and easy interruption of the measurements for the first view of measured structures. Further information on ARREESS System can be found at www.gfinstruments.cz.


IGT2010 – Innovative Geoscience Technology Conference

Posted by AP on Thursday, 13 May, 2010

May 19 – Denver, CO.

Special Educational Event – produced by the Denver Geophysical Society

2nd Annual Innovative Geoscience Technology Conference

Where: Hilton Garden Inn, Denver Downtown
1400 Welton Street Denver 80202

REGISTER AT: www.denvergeo.org
Denver Geophysical Society

KEYNOTE SPEAKER: Daniel M. Jarvie Worldwide Geochemistry
title: Geochemical Assessment of Rocky Mountain Shale Resource Plays and Prospects

FEATURED KICKOFF SPEAKER : Dan Likarish Regis University
title: The Use of Virtual Social Networks to Investigate the Influence of Deep Crustal Processes on the Occurrence of Faults and Fractures

Innovative Geoscience Technology Presentations

The Basement-Petroleum Connection: New Insights - M. Swan, MagnaChem Exploration, Inc.

3D Anisotropic CSEM Inversion
- C. Jing, Exxon-Mobil, Inc.

Evidence of Hydrocarbon Seepage Using Multispectral Satellite Imageryin Iraq
- S. Perry, Perry Remote Sensing, LLC

Integrated MT/Gravity Geothermal Exploration in Hungary: A Success Story
- G. Yu, KMS Technologies, LLC

New Aeromagnetic Compilation of Artic, Russia and Europe and its Inversion to Depth of Basement and Structure
- D. Fairhead, GETECH

Hydrocarbon Mapping in Mozambique with Airborne Geophysics

- J. Rudd, Aeroquest Surveys

CO2 Geologic Sequestration Begins and Ends with Geoscience Technology
- W. Row, Schlumberger Carbon Services

Shale Core Analysis Required for Gas Reserve Estimates
- C. Hartman, Weatherford Labs

Locating Abandoned Coal Mines to Assess Risk Using Self-Potential and DC Resistivity, Weld County CO
- K. Bohlen, Colorado School of Mines/ Encana


Advanced Geosciences Resistivity Imaging Seminars

Posted by AP on Wednesday, 12 May, 2010

AGI hosts three separate seminars many times a year. The Resistivity Imaging Seminar covers all aspects of electrical resistivity imaging methods. The Advanced Resistivity Imaging Seminar focuses on the resistivity imaging theory, survey design, in-depth understanding of resistivity imaging methods and hands-on practice of resistivity data processing. The new Marine Resistivity Imaging Seminar focuses on the continuous resistivity profiling (CRP)with an electrode streamer on the water, and underwater resistivity imaging with a bottom cable.

2010 Seminar Schedule and Location


Hydrogeophysics – a rapidly evolving discipline

Posted by AP on Monday, 29 March, 2010

SEG invites papers on the topic of “Hydrogeophysics — Electric and Electromagnetic Methods” for publication in the July-August 2010 special section or supplement of Geophysics.

“Hydrogeophysics is a rapidly evolving discipline of geophysical methods dedicated to revealing properties and monitoring processes in the vadose zone as well as in aquifers. The discipline is relevant for environmental, hydrological, and agricultural research and engineering. Key processes in the application areas are contaminant transport, sustainability of ecosystems and biodiversity, plant growth, and soil-atmosphere interactions. Groundwater is the key component in the subsurface pore volume, for which reason electric and electromagnetic methods are most suitable for addressing the problems related to shallow subsurface spatial and temporal variability, its inaccessibility, which hinders the observation of relevant processes, and its role in connecting atmosphere, surface, and groundwater/reservoirs.

For this topic, Geophysics invites papers describing the theory, application, and benefits of advanced methods of hydrogeophysics. The application scale may range from the pore scale to the field scale involving more than 1 hectare of surface area. In particular we welcome techniques that exploit the evolution of new passive and active electric and electromagnetic acquisition strategies and advanced data processing and inversion schemes that show an increase in computational speed. Finally, we also encourage papers that highlight case studies and thereby emphasize the practical aspects and illustrate the potential pitfalls, problems, and limitations of the applied techniques.”


DC resistivity and IP survey over Tesoro Gold Project in Peru

Posted by AP on Friday, 12 February, 2010

Everyone can look at the results of Titan-24 survey over the Gold Project.

Maps direct link http://www.steliasmines.com/titan24/images.pdf and interpretation model sections http://steliasmines.com/titan24/titan2d_xsectionFigures.pdf

St. Elias Mines Ltd. is owner of the Tesoro Gold Property located in Peru.  The Property covers approximately 1,700ha and is located in the Acari District within the prolific Nazca-Ocoño gold belt of southwestern Peru.  The Nazca-Ocoño gold belt is a 300km x 30km belt paralleling the Pacific coast of southwestern Peru.  Gold is associated with disseminated sulfides that seeped into quartz veins or rock fractures within the intrusive body.  The continuity of the quartz veins and fractures is very impressive in the Nazca-Ocoño belt since these veins are often hosted within fractures and shears that show continuity along several kilometers.  To date, more than 70 gold deposits have been exploited in this region since as early as the 17th century.
The veins located immediately north of the Property are being mined by Dynacor (TSX-DYN) who published an inferred gold resource of 606,611 ounces at 16.4g/t (on only 3 of 10 veins discovered to date).  The veins located immediately south of the Property have been in continuous production since the 1970’s and have produced over 700,000 ounces to date.  These veins have been mined over a 2,000m strike length to a depth of 1,000m.  Barrick Gold has recently acquired claims that adjoin St. Elias’ Property to the south.

Since the Property acquisition in March 2004, the Company has completed a Phase I exploration program and a Phase II exploration program is ongoing.  Prior to these programs, the Property was primarily unexplored.

The Phase I program consisted of control grid emplacement, reconnaissance geological mapping and prospecting over the entire Property, detailed geological mapping and sampling of all identified veins, trenching and sampling of wider structures that flank the veins and underground sampling of the Canchete 1 vein.

Since the completion of the Phase I program, the Company has assessed and prioritized the five main concentrations of gold mineralization (“zones”), as well as, other gold bearing areas within the Property.

The Phase II exploration program is ongoing with initial exploration efforts focused on the Zona Canchete Vein #1 (“ZCV#1”).  The ZCV#1 is a first priority target and is one of eight gold-bearing quartz veins located at Zona Canchete.

The Phase II program consists of detailed geological mapping, sampling, development of additional underground workings and the collection and processing of an initial 150-200 tonne bulk sample at the ZCV#1.  This work will assist in determining the horizontal and vertical extent of the vein, as well as, the vein’s physical and gold grade characteristics.

Detailed sampling from the existing underground workings confirms that both the gold values and the vein width are getting stronger with depth.  On the 40m-level, the overall grade and continuity of the veins are improving with distance away from the winze both to the east and to the west.  For example, the average grade of the vein between 10.5m east and 22.6m east (a distance of 12.1m) is 3.0 oz/T gold.  The average grade of the vein between 20m west and 24m west is 1.36 oz/T gold over an average vein width of 31.6cm.

St. Elias Mines Ltd.  provides further information following the recently announced results from the Titan 24 Geophysical survey conducted by Quantec GeoScience Limited on the Property.


The geophysical basis of Cree East uranium project

Posted by AP on Wednesday, 27 January, 2010

CanAlaska Uranium Ltd. has commenced exploration on its Cree East uranium project in the Athabasca Basin, Saskatchewan, Canada.



Previous geophysical modelling and initial drill tests have outlined four zones of uranium mineralization and hydrothermally-altered rocks associated with major basement offsets along a 4 km mineralizing trend. Drill-hole spacing in the target areas from previous drilling in 2008 and early 2009 is from between 100 to 200 metres. Most of the 2010 targets are located between existing holes, or are short step-outs from existing holes. The new drilling will attempt to cross-cut the fault and alteration modelled by the existing holes, geology and geophysics.

Additional targets on the Cree East project have been defined following intensive airborne and ground geophysical work over summer 2009.

CanAlaska carried out VTEM airborne surveys across the property area in 2005 and determined priority targets. In 2006, detailed collection of over 2,000 surface rock samples and over 400 lake sediment samples by CanAlaska’s field crews defined three large areas of dravite and clay alteration on surface, and localized boulder samples containing anomalous uranium. Before April 30, 2007, initial ground geophysical data from the first lines of IP-Resistivity surveys, provided the CanAlaska with evidence of strong alteration in the sandstone horizons overlying these basement conductors. Additional IP-Resistivity and Audio Magneto Telluric geophysical surveys were used to further define these targets this year. Drill programs started on the project in late February 2008 and large zones of alteration were intercepted. Extreme clay alteration and unconsolidated sands prohibited the CanAlaska from completing the majority of the drill holes.

During the summer of 2008, CanAlaska undertook a multi-faceted $1.6M exploration programme at its consisting of IP/Resistivity surveying on land and high-resolution single channel seismic data collection on Cree and McIntyre Lakes, lake sediment sampling on Cree Lake, and a 5- hole diamond drilling programme. All of the drill holes reached their target depth in basement.

In summer 2009 detailed geophysical surveys, and infill VTEM surveys were used to prioritize target areas for 2010 drilling.


The new geophysical targets – the new expectancies

Posted by AP on Friday, 8 January, 2010

PC Gold Inc. reports that more than a dozen excellent new targets have emerged from a recently concluded geophysical survey carried out over the Pickle Crow Gold Mine Property (details, below). The new targets, none of which have previously been drilled, lie beneath swamp both within the core mine trend and in areas lateral to it. Drill crews have been remobilized to the Property following the holiday break, and drilling of the first of these new targets has now commenced with a single shallow drill. To expedite testing of all targets while the winter cold-weather window allows, a second shallow-intermediate capable drill is expected to be added to the program later this month. This will bring to three (two shallow, one deep) the number of drills active on the Property. The two shallow drills will be active continuously in the January through April period, with testing of the new shallow targets to be concluded prior to spring break-up. Concurrently, drilling of a deep mother hole (PC-09-052) and wedges designed to test well below the deepest workings of the former mine will also continue.

In a press release dated June 1, 2009, the Company announced that potential exists for the Pickle Crow Gold Mine
Property to host previously unrecognized deposit types associated with sulphides, particularly beneath largely
unexplored areas of swamp and muskeg north and south of the core mine trend. In follow up, Quantec Geoscience
Ltd. carried out a 115 line kilometre magnetometer survey as well as a 70 line kilometre ground based Titan 24 DC
Resistivity / Induced Polarization survey, designed specifically to detect disseminated sulphides. The presence of
the new targets beneath previously unexplored portions of the Property is considered strongly encouraging.
Below is Geophysics (IP) grid lines over core mine trend / PC-Confederation contact and nearby areas, August 2009:

TITAN URANIUM LAUNCHES GEOPHYSICAL PROGRAMS in Athabasca Basin

Posted by AP on Monday, 21 December, 2009

Saskatoon – Titan Uranium Inc announces that it has commenced geophysical programs on several Athabasca Basin properties in Saskatchewan. A D.C. Resistivity and Max Min Horizontal Loop ElectroMagnetic (HLEM) geophysics program on Titan’s wholly owned Bishop I and Meanwell properties is now underway with results expected in January 2010.  In addition, geophysical work will be carried out over Titan’s R-Seven Project beginning in early January 2010 consisting of TDEM (Time Domain ElectroMagnetic) Moving Loop surveys with results expected by the end of the first quarter of 2010.

D.C. Resistivity is the geophysical technique of choice in the Athabasca Basin due to its ability to image hydrothermal alteration systems often associated with fault zones and unconformity-type uranium deposits.  The alteration zones show up as resistivity “chimneys” due to the significant contrast in resistivity between the structural zones and their surrounding rocks. The program will consist of ten lines totaling 20 line km, with line spacing of 150 m.
Max Min HLEM and TDEM Moving loop surveys are electromagnetic (EM) techniques used to detect and delineate conductors and conductive formations in the Precambrian basement rocks at or under sandstone cover.  Both EM surveys have been designed to optimize resolution within that interval. The surveys will consist of eleven lines of HLEM (24.2 km) and two lines of TDEM Moving Loop (17 km).

Most of the Athabasca Group sandstone rocks exhibited moderate to strong bleaching and clay alteration was well developed.  Strong alteration was found in basement rocks below the unconformity, mainly along fractures. Weak Uranium anomalies were observed in both the sandstone and basement rocks.