Archive for August, 2010

Chihuahua’s geophysical survey

Posted by on Wednesday, 25 August, 2010
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Dia Bras is a Canadian exploration mining company focused on precious and base metals in Chihuahua State and other areas of northern Mexico.

Dia Bras Exploration Inc. reports that a major geophysical survey has been completed on its 100% owned Bolivar Property which is not subject to any royalties, Chihuahua State, Mexico. Field checks have been conducted to examine anomalies detected during a recently completed Titan 24 Induced Polarization (IP)/resistivity survey contracted to Quantec Geoscience of Toronto, Ontario.  Two areas were covered during the survey, where eight lines totaling 9,000 metres were measured across the Banda Fault near the Bolivar Mine, and three lines totaling 2,700 metres were measured at the La Cascada high-sulfidation gold deposit. Condor Consulting of Lakewood, Colorado, has been retained by Dia Bras to assist in the planning of the IP/resistivity surveys and with the interpretation of the results.

“The surveys just completed at La Cascada and the Banda Fault areas have shown very promising results that confirm important mineralization can occur in these areas,” stated Daniel Tellechea, President & CEO. “These very positive results focus our drilling on targets that have the potential to host very important mineralization. At La Cascada, our target is a multi-million ounce gold deposit, while at the Banda Fault area our target is a major, stratabound skarn or replacement deposit with copper-zinc grades equivalent to what we have been producing from the Bolivar Mine for the past five years.”

La Cascada

Three survey lines at La Cascada were completed in this area of rugged terrain: a 1,000-m-long N-S line and two E-W lines (800 and 900 m), which resulted in detection of three significant chargeability and resistivity anomalies – all of which are associated with anomalous grades of gold in outcrop, as evidenced by the results of chip-channel sampling over 2-metre widths. The southernmost anomaly on the N-S line starts at 50 m depth. Sampling of outcrops over an area of 50 x 85 m was conducted prior to the survey and the six samples assayed 0.6 – 1.1 g/t gold.

Sampling in the area of the central anomaly (also starting at 50 m depth), completed over a 40 x 50 m area (also prior to the survey) resulted in the eight samples assaying 0.5 – 2.1 g/t gold.

Sampling in the area of the northernmost anomaly, completed over a 10 x 20 m area (also prior to the survey) resulted in the three samples assaying 0.4 – 3.0 g/t gold.

The sampled areas between the anomalies yielded very low grades of gold, generally less than 0.1 g/t.

These survey results are very positive because of the strong correlation between elevated gold in outcrop and strong chargeability anomalies. This correlation indicates that the probability that the three chargeability anomalies are associated with gold mineralization at shallow depths is very high.

The truncation of the chargeability anomalies at an apparent constant 50 m depth is inferred to be the result of oxidation of the high-sulfide zones, remnants of which appear on the surface as 1-2% pyrite and abundant jarosite, hematite and goethite.

Drilling will target the near-surface, coincident strong chargeability (IP) and resistivity zones detected during the survey. Drilling is scheduled to commence during late August, when an access road is completed to the selected drill sites. At least ten holes of 200-300 m depth each are planned for this first phase of drilling.

The area surveyed is only about 10% of the area known to host strong gold anomalies, where sampling has returned values up to 15 g/t Au.

Banda Fault

Eight E-W lines 600 m to 1500 m in length at the Banda Fault area were measured across this major, NW-trending fault. The objective of the survey was to locate geophysical anomalies associated with NW-trending and NE-trending faults. Faults of these orientations control the location of high-grade copper-zinc mineralization in the Bolivar Mine. The anomalies can be separated into two general groups: near-surface anomalies and sub-surface anomalies.

Each of the near-surface anomalies occurs in andesite and is associated with elevated sulfide content, usually 1-3%, epidote and minor silicification. The anomalies are generally on low hills, reflecting their being underlain by the resistant silicified rock. The anomalies on lines 3, 5, 6 & 7 indicate a NW-trending structure (herein named the Nathalie Fault) parallel to the Banda Fault that passes near Increíble. There are significant geochemical anomalies associated with this structure, which may be a very important feeder of mineralizing fluids into the metasediments. This structure may be the main feeder of the mineralizing fluids, and not the Banda Fault as has been inferred prior to the survey.

The sub-surface anomalies are generally located west of the Banda Fault and are in a position to be the stratabound, large-tonnage replacement and/or skarn deposits that have been a major target for the Company.

The survey results are very encouraging. It has identified the Nathalie Fault, which is now inferred to be the major feeder for mineralization at the property. Drill hole 287, completed in March 2009, was drilled to a depth of 650 metres as a test of the Banda Fault and was placed between the Banda Fault and the Nathalie Fault. It was collared on what is now known to be the edges of a chargeability anomaly, a magnetic low and a moderate resistivity anomaly. The chargeability anomaly tops out at 100 m depth at the drill site, and at this depth, the hole entered increasingly skarnified andesite with disseminated sulfide mineralization. At 450 m depth, the hole entered the metasediments, which are present as marble and represent the upper portion of the metasedimentary section – above the Upper Skarn target. That is, the hole did not reach the target of the Upper Skarn horizon.

The new interpretation is that the Nathalie Fault, which is west of hole 287, will have on its west side the Upper Skarn target at a shallower depth, possibly 300-400 m. This area will be drilled by placing a NE-SW line of holes about 200 m NW of hole 287 and straddling the Nathalie Fault. This is an important target.



Airborne Geophysical Survey of Coxheath Property

Posted by on Saturday, 21 August, 2010

Silvore Fox Minerals Corp. reports that it has entered into a contract with Aeroquest International Ltd. (“Aeroquest”) to conduct a comprehensive airborne geophysical survey over the Corporation’s flagship Coxheath copper porphyry property in Nova Scotia, Canada. Aeroquest will fly a 462 line-kilometre survey of high resolution Aero TEM IV MAG-TDEM and Radiometrics over areas of interest encompassing the Corporation’s mineral claims at Coxheath.

In addition, the Corporation has also contracted CGI Controlled Geophysics Inc. (“CGI”) to manage this airborne program on behalf of the Corporation. CGI has extensive experience with modern geophysical techniques, data processing, project management and geophysical interpretation.

This phase of the exploration program, as per the Corporation’s Press Release dated May 28th, 2010, is designed to provide new geoscientific information to help further the understanding of the mineral potential of the property. The results of the survey will aid in delineating the potential size and scope of the property’s structural framework and associated copper, gold, silver and molybdenum mineralization. In addition, the survey will provide important information on highly prospective and underexplored areas of the property, including the newly expanded, contiguous mineral rights. Follow-up field-work will focus on ground-truthing the results of this survey and the integrated data will be applied to develop a diamond drilling program that is anticipated to begin in September 2010. The details of the diamond drill program will be released at a later date.

“I am optimistic that the results of this survey will greatly advance our understanding of the geology and mineralization at Coxheath,” states Harry Cabrita, President and CEO. ”It will further enhance the efficiency of the exploration program that will have the assessment of economic significance as its primary objective.”


The new Key Lake SW Airborne Survey Results

Posted by on Tuesday, 17 August, 2010

Kirrin Resources Inc. today announced the results of the evaluation and interpretation of the 1,076 line-km magnetic-electromagnetic (Tempest(R) EM) airborne survey of the Key Lake Southwest (‘Key Lake SW’) uranium property located on the southeastern margin of the Athabasca Basin in Saskatchewan. The Condor Consulting Inc. report identified 7 first priority, 5 second priority and 7 third priority targets that warrant follow-up assessment. Some of these anomalies correlate with geological, geophysical or geochemical anomalies identified from prior exploration, whereas others are newly identified. All are prospective for ingress style (i.e., basement hosted) uranium deposits along the geologically favourable Wollaston Group basement trend.

Commenting on the results, Kirrin President and CEO, Derek J Moran said: “These results have added substantial value to the Key Lake SW uranium project, and show clearly its potential for another eastern Athabasca uranium discovery.”

Processing, interpretation and correlation of the results with magnetic response and geology define two main types of conductors, discrete plate-type and broader, flat lying wide zones (Note 1). These have been further grouped by Condor into 19 target zones and subjectively ranked, according to their conductivity, magnetic association, strike extent and geological association, from high to low priority, with 7 target zones being ranked first priority. Historic wide-spaced drilling on parts of four of the 19 target zones identified prospective geology, including a possible sub-Athabasca Group regolith that was logged in several holes which are located within a Wide Zone EM conductor.

The number one priority target zone has good potential for uranium mineralization because significant uranium values within wide zones of graphitic pelites have been intersected in drill holes targeted along the northeastern extension of this conductor lying within Triex’s Riverlake and Forum Uranium’s Orchid properties. There are 9 other target zones (for a strike length of 52.9 km) which display similar geological and geophysical conductive and magnetic characteristics as observed on adjoining properties and over other uranium deposits in the region and thus are ranked as having high potential for uranium mineralization. The survey also showed that some target zones at Key Lake SW have potential for base metal mineralization or iron formation similar to the geological horizons mapped in the McArthur River mine.

Kirrin is planning the next stage of exploration at Key Lake SW. Follow-up fieldwork at selected first priority targets is likely to comprise (a) systematic prospecting of anomalous conductive trends to prioritise drill targets along those trends, (b) follow-up geochemical lake sediment and possibly soil surveys, (c) magnetic and electro-magnetic surveys on grid areas established over first priority target zones in order to locate conductive axes and attitudes for drill collar positioning, and (d) drill testing of selected targets.

Note1: Magnetic surveys, structural geology, drill and surface geochemistry compiled over the eastern portion of the Athabasca Basin indicate that uranium enrichment and deposits are associated with conductive horizons, located within or along magnetic low troughs, which typically represent graphitic and sometimes magnetite rich iron formations and associated contacts. These horizons are flanked or sandwiched between magnetic highs, which represent underlying Archean type granitoid domes or arches. The reduced magnetism is caused by regional faults, which provide control and form traps for uranium enrichment. The graphitic rich pelite horizons in the basement rock are excellent conductors and host uranium mineralization. They act as markers as they can be located with electromagnetic surveys and targeted with drill holes.


MacDonald Mines Acquires Hornby Properties with promising geophysical data

Posted by on Tuesday, 17 August, 2010

MacDonald Mines Exploration Ltd.  announces that it has finalized an agreement to acquire 100% of the Hornby and Pender Properties, located in the “Ring of Fire” area of the James Bay Lowlands, with Temex Resources Corp. An exploration update follows the agreement details below.

The Hornby Property

MacDonald Mines Hornby Property is located contiguous to the KWG/Spider “Big Daddy” chromite deposit. The Company believes, based on a total review of its airborne survey and historical exploration data, that the Hornby Property has the potential to host the extension of the Big Daddy deposit.

The Property also exhibits prospective volcanogenic massive sulfide (VMS) (copper, zinc and lead) geophysical targets and is on same stratigraphy as Spider/KWG McFauld’s Lake VMS discovery. Historical drilling in the proximity of this prospective target intersected VMS mineralization.

Exploration Update

As detailed in the Company’s recent press releases, MacDonald Mines has several significant mineral opportunities across multiple properties in the James Bay Lowlands. The spring 2010 drill program consisting of 26 holes, 4,471 meters and focused on the McNugget Property and identified new VMS mineralization of substance on four fold limbs.

A summary of the highlighted drill holes reported were as follows;

Copper (Cu)

  • Hole MN10-102 intersected 1.03% over 15 metres
  • Hole MN10-111 intersected 1.04% over 5 metres
  • Hole MN10-90 intersected 1.11% over 5 metres

Zinc (Zn)

  • Hole MN10-104 intersected 3.3% over 9 metres
  • Hole MN10-106 intersected 2.55% over 4 metres
  • Hole MN10-110 intersected 2.82% over 5 metres
  • Hole MN10-102 intersected 2.5% over 3 metres
  • Hole MN10-104 intersected 2.00% Zn and 0.88% Cu over 6 metres

Silver (Ag)

  • Hole MN10-87 intersected 13.32 g/t over 5.3 metres
  • Hole MN10-94 intersected 16.56 g/t over 4 metres
  • Hole MN10-102 intersected 11.67 g/t over 3 metres
  • Hole MN10-104 intersected 11.97 g/t over 3 metres

Final assays from this last phase of drilling are pending and will be reported once they have been received and reviewed by the Company.

This large VMS system, which is open in all directions and yields VMS mineralization over a potential cumulative strike length of approximately 20 kilometres, was described by consulting geologist Hadyn R. Butler, P.Geo, as potentially being a new VMS camp.

Next Phase of Drilling to Commence Early September With 2 Drills

Crone Geophysics’ down-hole and surface EM system was employed in the previous phases of exploration, assisting in the discovery of the four VMS mineralized fold limbs, and will again be utilized for the upcoming drill program for drill target control.

The Company will continue to operate two drills for this upcoming drill program and will focus on the positive results from its successful spring 2010 drilling program on the McNugget Property.

Targeting Nickel and VMS on McNugget Property


VMS

The pyrrhotite-chalcopyrite-sphalerite-pyrite mineralization observed in the core of the McNugget property is indicative of VMS mineralization. The pattern of chlorite and sericite alteration, coupled with varying Cu/Zn ratios and alteration index plots from available geochemistry, indicates that there are at least three separate hydrothermal discharge vents/centres found within the same stratigraphic horizon of a large fold complex (McNugget).

Sulphide mineralization observed in drill core generally appears between footwall metasediments and hangingwall felsic volcanics, a lithologic sequence indicative of a Bimodal-Siliciclastic VMS environment.

Based on alteration mineralogy, geochemical vector analysis and 3-D geophysical modelling, it appears that the significant VMS mineralization intersected to date is peripheral to the volcanic centres (sources).

The Company’s current information is pointing to the Fold Nose found on the property as the most immediate prospective appreciable VMS mineralization. A surface and airborne electromagnetic (EM) survey are currently underway on the Fold Nose – and these results will direct the drilling program.

Nickel

The highest priority nickel target on the McNugget property remains to be in the vicinity of MN07-39. A completion of the airborne magnetic and EM, and Noront Resources’ recent image of the Eagles Nest indicates that the same magnetic horizon extends from the Noront discovery through the McNugget property – adjacent to MN07-39. Prior to further drilling, this area will be investigated further using the following geophysical techniques – VTEM and AeroTEM IV, magnetics, and Crone Geophysics surface and down-hole pulse EM system.



IP Survey Expands Potential of Schaft Creek Deposit

Posted by 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.


Worldwide VLF transmitters list

Posted by on Friday, 13 August, 2010

Several radio transmitters operate throughout the world in the VLF range, 15-30 kHz, and are used mainly for marine navigation, communication with submersed submarines, and other purposes.  The principle of VLF subsurface exploration is simple.  At large distances from the transmitter, the EM field is effectively planar and horizontal.  A conductor that strikes in the direction of the transmitter is cut by the magnetic vector, and these primary magnetic fields cause electric currents to flow in subsurface conductors.  In another, more recent, theory, the subsurface currents flow along interfaces between bodies of differing conductivity.

The Very Low Frequency (VLF) radio spectrum extends from 3 to 30 kHz. Standard communications receivers do not receive signals that low in frequency. Furthermore, most antennas used with standard communications receivers are optimized for higher frequencies and perform poorly in the VLF spectrum. Because of that, few Radio Amateurs or shortwave listeners have ever heard VLF signals and most know very little about the large number of stations in that part of the spectrum, what those stations are used for, or the nature of VLF radio signal propagation.

However, because VLF receivers and receiving antennas are easy to construct, the VLF spectrum attracts a small number of curious and sometimes very dedicated VLF listeners who want to learn more about this little-known and somewhat secretive part of the radio spectrum.

Signals from powerful VLF stations can be received worldwide. They penetrate deep into the earth and deep into the sea (especially in the lower portion of the VLF spectrum) and therefore can be received by submerged submarines. Though some VLF stations have other purposes, the primary function of most VLF stations is to communicate with submerged military submarines or help them navigate underwater.

http://www.smeter.net/stations/vlf-stations.php


Ultra-high resolution magnetic survey for kimberlites

Posted by on Friday, 13 August, 2010

Shear Minerals Ltd. today announced the discovery of the new high interest SAZ kimberlite float and the commencement of the $500,000 exploration program at the Chesterfield Inlet Diamond Project, Nunavut in partnership with Rio Tinto Exploration Canada Inc. (“Rio”) and Stornoway Diamond Corporation.

Already completed this year is a 2,346 line km ultra-high resolution airborne magnetic geophysical survey over two priority blocks by Aeroquest.  A total of 33 priority targets have been chosen as large tonnage kimberlite targets.  A 10-person experienced crew is currently at the Josephine Lake Camp and will follow up targeted anomalies on the ground. A total of 7-10 high priority targets will be tested using a lightweight reverse circulation percussion drill (tests one target per day).

“The goal for this project in 2010 is to discover new kimberlites with large tonnage potential. The discovery of the new SAZ kimberlite float suggests the presence of high diamond potential kimberlites in the Chesterfield area,” said Pamela Strand, President and CEO of Shear Minerals Ltd. “With drilling now underway we hope to quickly confirm whether a target is a high diamond potential kimberlite to warrant further follow-up.”

SAZ Kimberlite Float
The SAZ kimberlite float was discovered by prospecting in a series of nine frost boils within a 65m area. The kimberlite fragments are weakly magnetic, angular and are believed to be proximal to the source. Visually the kimberlite is described as being ‘typical’ of the high diamond potential kimberlites at Churchill (“Type B”) with large olivine macrocrysts, green-blue phlogopite and visible pyrope garnets.  Samples have been collected for diamond analysis by way of caustic fusion as well as petrography. Plans are to review the geophysics with continued prospecting in this immediate area.

About the Project and Shear Minerals
The Project comprises a group of 35 mineral claims (70,000 acres) located within and near the North Corridor of the larger Churchill Diamond Project.  The Project area is located approximately 15 km north of the Josephine River Corridor.  This area covers the North Corridor, an indicator mineral dispersion area based on till samples from 2003-2006 having high count probe-confirmed kimberlitic indicator minerals including pyrope garnet, eclogitic garnet, chrome diopside, ilmenite and chromite.


Rio de Janeiro, September 20-23, 2010

Posted by on Thursday, 12 August, 2010

The Brazilian Geophysical Society (SBGf) is organizing in 2010 a Forum to focus discussions on the application of non-seismic methods for Oil and Gas Exploration.

Modern geophysics was born with non-seismic methods when Conrad Schlumberger conceived the revolutionary idea of using electrical measurements to map subsurface rock bodies in 1912.

After almost a century the non-seismic methods are still revolutionary on the geophysical world bringing new ideas and methods for the exploration of natural resources.

Present days, the oil industry emphasizes the use of geophysical techniques because of their minimum impact to the environment. By having in mind that the large reservoirs are hard to discover and expensive to develop the industry is searching for new technologies which are able to provide valuable information for the exploration and production of these areas in an efficient and more cost-effective way. We hope to have examples from offshore and onshore applications of the non-seismic methods from South America, Gulf of Mexico, North Sea, Middle East, Russia and other important oil producers worldwide.

The Organizing Committee expects to receive 150 delegates from Brazil and abroad. Participants will include geophysicists and exploration specialists within the oil and gas industry.

The forum provides an opportunity to explore the application of non-seismic methods and areas where they’ve proven to be successful in oil and gas exploration. Forum organizers have invited geoscientists to share their ideas and experiences by submitting presentations on the topics of Potential Fields Methods, Electric and Electromagnetic Methods and Borehole Geophysics.

While no oil and gas discoveries are made without the use of seismic methods, other geophysical methods can contribute to more reliable evaluations in deeper, more challenging environments, such as subsalt structures and deep sea environments. By cost-effectively gathering geophysical data to narrow the search area within large fields, oil and gas explorers can refine their targets and apply seismic techniques more productively.

Geosoft Among Participants of SBGf Forum on Non-Seismic Methods

“The SBGf chose to focus on non-seismic methods for its 2010 forum because of increasing interest and success in the use of other geophysical methods within oil exploration,” says Ana Cristina Chaves, Managing Director, Geosoft Latinoamerica, and a member of the SBGf forum organizing committee. “In recent years, potential field geophysics has played a role in significant discoveries in the subsalt structures of offshore Brazil and the Gulf of Mexico. With deeper exploration, there are also greater environmental concerns and geophysical techniques that have less impact on the environment are favoured over more invasive methods. As a result, we’ve seen major oil and gas companies expanding or starting new gravity and magnetic programs.”

“The degree of complexity within Oil and Gas exploration today is driving a resurgence of gravity and magnetic methods,” said Jorge Hildenbrand, Managing Director of Fugro Airborne Surveys in Brazil and a member of the SBGf committee organizing the forum. “There are many environments where seismic does not respond well, such as salt domes and volcanic horizons, and geophysical potential field data, properly modeled, reduces the uncertainty caused by non-homogeneous lithologies. Potential field methods, including airborne gravity gradiometry, and the application of electromagnetic methods (both marine and ground) are showing a lot of promise, and the forum will provide an opportunity to share case studies on how they are being applied in the field.”

Robert Ellis, Geosoft Senior Scientist, Earth Modelling, will present a paper on Non-Uniqueness in Potential Field Data with application to the Bacia Portiguar at the forum. Exploration relies heavily on using geophysical observations to aid in building a model of the Earth’s subsurface, and Ellis will explore how this is achieved by solving a geophysical inverse problem that recovers a causative physical property model from its geophysical response.

http://www.geocomm.com/


Extending Gold And Base Metal Potential with 3D IP survey

Posted by on Tuesday, 10 August, 2010

Indonesian-focussed Robust Resources has revealed that a 3D IP-Resistivity survey over the flagship Lakuwahi target, as well as new drilling results, have significantly extended the discovery target zones and therefore the gold and base metal resource potential on Romang Island.

The IP-Resistivity geophysical survey commenced on 24 March 2010, and field data collection is 50% complete, with 20% of information processed and modelled.

The geophysics and drilling has confirmed a well-defined geophysical (resistivity) anomaly area that is 20-times larger than current Batu Mas drilled prospect and remains open.  Importantly, there appears to be continuity of precious and base metal mineralisation structure confirmed between main drilled prospects of Batu Mas and Batu Hitam (over 2 kilometre strike length).

Recent drilling at Batu Mas and Batu Hitam continue the strong track record of results with thick intersections of precious metals and base metals on both prospects. In total, results for fourteen holes have been received, eleven of which intersected mineralisation of potential economic significance.

Managing director Gary Lewis said, “In this latest stage of our exploration program, Robust has done the reverse of most companies in that we have drilled prior to embarking on the geophysical studies which puts us in the now fortunate position of being able to calibrate the geophysics with drilling data.”

“Based on the excellent correlation of geophysical anomalism with the drilling data, the results have not only extended the Batu Mas target zone by around 20-times its current size, but also demonstrated that the geophysical anomaly clearly links the Batu Mas and Batu Hitam prospects, he said.”

“Whilst the Company had long suspected that this was the case, these latest results provide us with more confidence to move towards defining a maiden JORC resource from these two prospects alone. In addition, the IP has also identified a number of new drill targets, in particular those hidden under limestone cover, which we will shortly begin to target with our four owner-operated rigs.”

Batu Mas

Results for nine diamond drill holes have been recently received, with seven of the holes with coincident geophysical anomalism intersecting precious and / or base metals of potential economic significance. The very close fit between the drilling results at Batu Mas and the resistivity anomalism is especially significant, both in relation to validating the geophysical methodology and for demonstrating the extent of the potential resource at Batu Mas. The positive drilling results (both gold/silver and base metals) are all contained within the geophysically defined 50 Ohm-m contour, which concurs closely with the grade-thickness.

Gary Lewis continued, “The correlation of the positive drilling results and the resistivity represents a valuable enhancement of our understanding of the Lakuwahi mineralisation. We now have confidence that the extensions to the Batu Mas mineralisation and the new targets indicated by the resistivity, which so far is indicated to be in the order of 20-times the size of the Batu Mas area itself, are indeed likely to contain significant precious metal and base metal mineralisation.
Robust’s current drilling plan has been modified in light of the new results and testing of the Batu Mas
North target has already commenced.”


1970′s IP for the new exploration program

Posted by on Sunday, 8 August, 2010

Linear Metals Corporation announces that it has initiated a two-stage exploration program on its LaMorena Copper-Silver Gold project in Coahuilla State, Northern Mexico. The project is located approximately 250 kilometres southeast of Chihuahua, and 40 kilometres north of the Hercules iron mine (skarn), within a known belt of deformed sediments that host Carbonate Replacement Deposits (“CRD”s) such as MAG Silver’s recent Cinco de Mayo discovery, and at least in part, Goldcorp’s Penasquito deposit. Within this overall belt, LaMorena is located at the intersection of prominent regional northeast and northwest trending faults.

Schematic model showing the mineralization style and targets at the La Morena Property.

Previous drilling by Linear Metals and Linear Gold Corp., as well as earlier historic drill holes were focused on outcropping, sub-vertical vein structures and not the potential for deeper, sub-horizontal CRD (“Manto”) and skarn mineralization. Even so, previous drilling intersected significant copper and silver mineralization with intervals of up to 1,245 g/t silver and based on re-examination of drill logs, the better mineralized intervals in drill-holes M-1, M-2, and LM-4, may be from sub-horizontal CRD horizons.

Exploration at LaMorena has commenced this week and will include an initial geophysics program followed by diamond drilling. The exploration program will begin with ground truthing of the near-surface induced polarization (“IP”) chargeability-resistivity targets interpreted from the historic IP survey. This will be followed by “confirmation” re-surveying of most targets, especially the deep targets, using modern, deeper-penetrating IP equipment.

Area of high resistivity at the La Morena Property showing the drill-hole location and a circular topographic depression in the area.

As phase two of the exploration program, approximately 1,500 metres of diamond drilling will test the highest priority IP targets.

Re-interpretation of historic IP survey data (1970′s), recently recovered from the JICA archives, has confirmed that most of the originally interpreted near surface targets remain untested, while also defining six new untested deeper chargeability targets identified at 75 to 175 metres vertical depth.

The historic IP targets are located within the halo of a large, 1.5 kilometres x 3.5 kilometres, ovoid area of re-crystallized and lesser skarn-altered limestones of the Aurora, La Pena and El Cupido formations. The latter two formations are particularly prospective regionally, as they host numerous known CRD deposits such as Providencia-Concepcion Del Oro. The altered area is presumably underlain at depth by an intrusive stock and/or dyke swarm, indicating a potential for skarn and perhaps porphyry-style mineralization.



PEREGRINE’s new discovery

Posted by on Sunday, 8 August, 2010

Peregrine Diamonds Ltd. reports the discovery of two new kimberlites, named Q1 and Q2, by prospecting on the Company’s 854,000 hectare Qilaq project (“Qilaq” or “the Project”) on Baffin Island, Nunavut, Canada. Qilaq is located on Hall Peninsula, northeast of Iqaluit, the capital of Nunavut, and is adjacent to Peregrine’s Chidliak project (“Chidliak”) where, as reported in a news release on August 4, 2010, the Company has discovered 32 kimberlites in the past two years.

In the spring of this year, Peregrine conducted a 670 line-kilometre helicopter airborne geophysical survey on what represents less than 2% of Qilaq’s area. The 12 geophysical anomalies that were found from this limited survey were prospected and will be prioritized for ground geophysics to be followed by drilling next year. A larger airborne geophysical survey is also being planned for next spring.

Mr. Eric Friedland, Peregrine’s CEO stated “The recent discovery of two kimberlites at surface at Qilaq by prospecting shows that the kimberlite district we have discovered on south Baffin Island continues to expand substantially in area and that this region has excellent potential to host another Canadian diamond mine. Our targeting and exploration methods are producing new kimberlite discoveries at a very rapid pace in Nunavut, and we look forward to more discoveries at Qilaq in the near future. The fact that Qilaq is wholly-owned by Peregrine is especially exciting for our shareholders as it allows us to benefit fully from the value that could result from the potential development of the Project.”

Q1 KIMBERLITE

The spring 2010 helicopter-borne magnetic/electromagnetic geophysical survey revealed a magnetic high anomaly with an estimated diameter of 150 metres associated with a topographic depression that measures approximately 60 metres by 50 metres. Subsequent prospecting led to the discovery of the Q1 kimberlite, represented by large concentrations of coarse-grained KIMs, and kimberlite cobbles and boulders on the surface. Both magmatic kimberlite and probable weathered kimberlite breccia boulders were identified. Pyrope garnet, picroilmenite and chrome diopside grains over 10 millimetres in size were observed on the surface. Clasts of limestone, shale and sandstone, interpreted to have weathered from the kimberlite, are also present on the surface.

Q2 KIMBERLITE

The Q2 kimberlite is located approximately four kilometres south of the Q1 kimberlite and outside of the 2010 airborne geophysical survey. Q2 was discovered through the identification of kimberlite boulders by a field crew that was collecting a follow-up till sample. Subsequent prospecting led to the discovery of two kimberlite outcrops within a surface depression that is more than 80 metres in diameter. At least two phases of kimberlite were identified. One phase is described as being magmatic without limestone xenoliths and the other phase has coarser grained olivine and KIMs and contains limestone xenoliths. Both phases contain olivine, picroilmenite, pyrope garnet and chrome diopside macrocrysts.

Samples from the Q1 and Q2 kimberlites are being sent to the Saskatchewan Research Council for diamond analysis by caustic fusion and results will be reported as they become available. If the diamond results are positive, Q1 and Q2 will be scheduled for drilling as early as possible next year. An exploration summary showing the two new kimberlite discoveries is available athttp://www.pdiam.com/i/pdf/qilaq632.pdf.

QILAQ EXPLORATION UPDATE

Over 300 follow-up sediment samples, related to the seven KIM anomalies identified in 2009, are currently being collected in addition to the prospecting of anomalies revealed from the 2010 airborne geophysical survey in anticipation of a drilling program that is being planned for the next field season. Follow-up geochemical and rock sampling, prospecting and mapping related to precious metals anomalies identified in 2009 is also underway this field season.


Protest against seismic study on Paracel Islands

Posted by on Saturday, 7 August, 2010

Hanoi – The Vietnamese government on Thursday protested seismic study activities by China and the country’s expansion work in the Tri Ton Island area of the Paracels Archipelago.

“China’s actions have violated Vietnam’s sovereignty over the Paracels Archipelago, Vietnam’s sovereign rights to the continental shelf, the 200-nautical-mile Exclusive Economic Zone, going against the spirit of the Declaration of the Code of Conduct in the South China Sea (…),” said government spokeswoman Nguyen Phuong Nga.

Nga said since late May, China had been sending the M/V Western Spirit seismic survey vessel, together with escort ships, to conduct seismic studies in the Tri Ton Island area and in oil and gas exploration lots 141, 142 and 143 on Vietnam’s continental shelf, approximately 90 – 116 nautical miles (167 – 214 kilometres) from Ly Son Island of Quang Ngai province.

China has also been carrying out ground leveling on Tri Ton Island for construction works on this island, Nga said.

Vietnam’s foreign ministy raised the matter several times withEeijing, but “China is continuing those activities,” Nga said.

China has occupied the Paracels since 1974 when its troops overwhelmed a South Vietnamese garrison occupying the islands. China has seized hundreds of Vietnamese fishermen fishing near the Paracels for the past years for “infringing China’s territory.”

Both Vietnam and China are signatories to the 2002 Declaration on the Conduct of Parties in the South China Sea. It commits the parties to resolving the islands’ status through negotiations and provides for freedom of navigation.

The US Secretary of State Hillary Rodham Clinton in July called on the Association of South-East Asian Nations and China to reach agreement on a full code of conduct in the South China Sea to prevent conflicts.

She also pushed for proper settlement of the South China Sea issue through multilateral negotiations, but China rebuffed as saying it favoured a bilateral negotiations.

The South China Sea is believed to contain substantial undersea oil reserves.

Copyright DPA


GSC Airborne Geophysics covers Nox Fort Property

Posted by on Friday, 6 August, 2010

A recently released helicopter-airborne geophysical survey completed by the Geological Survey of Canada (GSC) covered a portion of the southern part of the Kootenay Arc in southwestern BC, including most of the Company’s Nox Fort Property.

The Nox Fort Property, located southwest of Salmo, contains several gold prospects including a number of high-priority exploration targets. The geology of the Property is diverse, consisting of pelitic and volcanic sediments, and large granitic intrusions which, at their contacts holds the potential for Reduced Intrusion Related Gold Deposits (RIRGD). The former Bunker Hill mine in the center of the Property is recognized as a RIRGD-type Au-Bi-Te prospect. Other gold occurrences are known including the Bluestar showing which contains gold along with silver and elevated copper, lead and zinc values. The Property has not been a target for base metal exploration by the Company although a past producer, Remac Zinc, is located to the south of the property.

The GSC airborne survey was conducted through the autumn and winter of 2008-09 by Fugro Airborne Surveys using a helicopter-borne time-domain electromagnetic (EM) system in conjunction with a separate magnetometer survey. The survey was flown at 200-meter line spacings with readings recorded at ground elevations of less than 500 meters. The GSC issued a series of maps on 30 June 2010 including Open Files 6194 and 6195 which cover all but the northwest portion of the Nox Fort Property.

The magnetometer data is presented as contoured readings while the EM response is represented by point anomalies of various strengths. The Company has produced generalized highlight maps to accompany this press release at its website.

EM Anomalies

Flanking the Bunker Hill mine are a pair of 3 kilometer-long northeast trending clusters of EM anomalies that fall southeast and northwest of the mine area. That northeast trend generally conforms to the strike direction of the underlying pelitic and volcanic sediments.

The largest cluster of EM anomalies begins south of the Bunker Hill mine then widens as it runs southeast and east of the mine before terminating at the Wallack Creek stock. In spite of the Company completing a number of reconnaissance traverses in that area during its field programs of 2008 and 2009, it is not clear what geological feature can be attributed to that response.

Paralleling Limpid Creek northwest and north of the Bunker Hill mine, the string of GSC survey airborne EM anomalies are coincident with a pair of localized soil geochemical anomalies and a very prominent ground geophysical anomaly reported by earlier workers. Zinc was the prominent soil geochemical anomaly often supported by silver, lead and nickel. Historic ground geophysical survey EM and magnetic anomalies are coincident and enveloped by the new GSC airborne trend.

A scattershot of EM anomalies northwest of Bluestar falls on ground that was partly covered in a reconnaissance till survey by the Company in 2008. Some of those samples were somewhat elevated in gold and arsenic, and another sample was anomalous in lead. This area is also intersected the Waneta Fault, a significant regional structure that may have had an influence on the prospective nature of that area.

Magnetic Anomalies

Magnetic response on the Property is dominated by a large positive anomaly centered over the granitic Wallack Creek stock that extends to the east, outside the mapped margin of the intrusive. The magnetic response is generally quieter elsewhere on the Property.

Northwest of the Bluestar gold occurrence, a magnetic high adds interest to the area. The Waneta Fault also crosses through this anomaly where geochemical sampling completed by the Company has targeted the area for mineral exploration.

North of the Bunker Hill mine a magnetic low straddling Limpid Creek may be significant as it corresponds to a small mineralized showing located by the Company in its 2008 field program. A sample of that quartz lens assayed 1.1 gm/tne gold and 4.9 gm/tne silver. Anomalous stream sediments, gathered by the Company in 2008 and last year, just upstream, are part of the high-priority north Limpid Creek exploration target that extends to the northeast for 1.5 kilometres.

The Company is pleased to have this additional new GSC airborne geophysical survey data and maps to assist in its future decision making process.


Airborne Survey Defines Major Iron Ore Target in Cameroon

Posted by on Sunday, 1 August, 2010

African Aura Mining Inc.  listed exploration to production company focused on iron ore and gold in sub-Saharan Africa announces the results of the recently completed airborne geophysical survey undertaken by New Resolution Geophysics across the Company’s Nkout, Ngoa and Akom iron ore projects in southern Cameroon.

Highlights:

  • Nkout defined by a major geophysical anomaly covering at least 8km of strike length
  • Further 12km of targets generated around Nkout, considered to be moderately magnetic
  • Previous grab sampling at Nkout returned up to 68% Fe and averaged 55% Fe
  • Phase one 4,200m 10 hole drilling programme to commence imminently
  • Nkout deposit is strategically well located in an emerging iron ore province:
    • 2.5 billion tonne Mbalam iron ore deposit (located 150km to the south east)
    • Close to the proposed rail route to a port which will service the Mbalam deposit

African Aura has received the interpretation of the data from the recently completed ground and 14,000 line km high resolution airborne geophysical surveys (EM and gravity) covering the company’s Nkout, Ngoa and Akom iron ore projects in Southern Cameroon. The data for Nkout suggests the presence of an east-west striking antiform with two limbs approximately 100m thick and magnetic susceptibilities of around 2.0, which is considered consistent for a prospective banded iron formation.

Luis da Silva, President & CEO of African Aura commented:
“Until today this asset was not valued in our portfolio. The results from the airborne geophysical survey at Nkout and our surrounding projects in Southern Cameroon are nothing short of highly encouraging. They confirm our belief that we have discovered a potentially very significant iron ore asset in a rapidly emerging iron ore province in west Africa. Nkout is represented by an approximately 8km long priority geophysical signature, co-incident with a major hill. As previously announced reconnaissance sampling by African Aura at Nkout, returned a maximum grade of 68% Fe and an average of 57% Fe from 55 samples. A ten hole 4,200m phase one drilling programme is planned to commence imminently, in order to test the highest priority signatures to refine the geological model and progress the project towards a maiden iron resource still during 2010. We look forward to updating shareholders on progress in due course.”

Nkout Iron Ore Project, Southern Cameroon
The Nkout iron ore project is located on the 489km2 Djoum licence. The project was identified through interpretation of historic airborne magnetic and remote sensing data. Mapping undertaken to date has shown that Nkout comprises a 12km long, iron rich (Itabirite / BIF) discontinuous ridge hosted in Archaean age rocks on the Congo Craton. Reconnaissance sampling at Nkout has returned assays with a maximum grade of 68% Fe and an average of 57% Fe from 55 samples.

Archive airborne magnetic data indicates a 10km long, domain change dipole interpreted as an area of highly magnetic rocks likely to host Banded Iron Formation (“BIF”) targets in an Archaean setting. The Company considers that the dimensions of Nkout and surrounding hills represent a potentially economic iron deposit.