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Earth Explorer is an online source of news, expertise and applied knowledge for resource explorers and earth scientists. Sponsored by Geosoft.

News & Views

News Archive

December 7, 2016

Geosoft introduces IP and resistivity inversion in VOXI Earth Modelling

Geosoft has added induced polarization and resistivity data inversion to its VOXI Earth Modelling 3D inversion software service. Geoscientists are now able to create detailed 3D models of conductivity and chargeability from IP and resistivity survey data with VOXI. The resulting models can assist in interpreting and targeting regions for mineral and environmental applications...

December 5, 2016

Mexico's Deepwater Round Exceeds Expectations

Some of the world's biggest oil companies showed up Dec. 5 and agreed to invest on the Mexican side of the Gulf of Mexico, proving that deepwater exploration still has a pulse despite challenging market conditions...

November 30, 2016

Magnetic inversion results for Ngamiland available for download

A regional-scale geophysical inversion of magnetic field data in the Ngamiland region of northwestern Botswana is now available for download from the Botswana Geoscience Portal, a partnership initiative of the Botswana Geoscience Institute, industry sponsors and Geosoft...

November 30, 2016

LIGO Resumes Search for Gravitational Waves

After a series of upgrades, the twin detectors of LIGO, the Laser Interferometer Gravitational-wave Observatory, have turned back on and resumed their search for ripples in the fabric of space and time known as gravitational waves. LIGO transitioned from their engineering test runs to full science observations at 8 a.m. Pacific Standard Time on November 30...

November 9, 2016

International Volcano Scientists Unite

For the first time, the United States will host the international Volcano Observatory Best Practices workshop, previously held only in Italy. The workshop will take place this month in Vancouver, Washington. It is designed specifically for volcano observatories around the world and their staff to exchange ideas and best practices with each other...

October 4, 2016

USGS Assesses Mineral Potential for Sagebrush Habitats in Six Western States

USGS has completed a comprehensive assessment and inventory of potential mineral resources covering approximately 10 million acres of Federal and adjacent lands in Idaho, Montana, Nevada, Oregon, Utah and Wyoming...

October 3, 2016

Uganda Targets Up to U.S.$100 Million for Mineral Exploration

Uganda is well endowed with mineral resources and, like many naturally-gifted African countries, is becoming keen on ensuring that these resources play a transformative role in its long-term structural transformation dream - the Vision 2040...

September 9, 2016

Small-Scale Fishers Get A Big Boost With First-Of-Its Kind Impact Investment Fund

Conservation organization Rare announces the Meloy Fund for Small-Scale Fisheries at Our Ocean Conference. The Global Environment Facility, one of the largest funders of conservation worldwide, will be investing $6 million into the fund...

September 1, 2016

Scientists take to the skies to track West African pollution

Scientists operating research aircraft over West Africa have detected organic materials in the atmosphere over a number of urban areas, contributing to concerns of the rise in pollution across the region...

August 17, 2016

New IGS Xplore prospectivity maps for Botswana

International Geoscience Services have released a series of base metal prospectivity maps for the Ngamiland District of northwestern Botswana using free geodata available on the recently-launched Botswana Geoscience Portal, hosted by Geosoft. The maps identify favorable areas for copper, zinc and lead mineralization using geological, geochemical and geophysical datasets downloaded directly from the portal.

August 11, 2016

NexGen Makes New High Grade Discovery

NexGen Energy reported the discovery of a new high grade zone of mineralization 4.7 km northeast of the Arrow Deposit as part of an on-going summer drilling program on its 100% owned, Rook I property, Athabasca Basin, Saskatchewan...

August 10, 2016

Rampion UXO Disposal to Take Place This Week

E.ON has confirmed that the two unexploded devices, detected along the Rampion offshore cable route will be safely disposed this week following the consultation with the Marine Management Organisation...

August 9, 2016

Diamonds In The Rough: E&Ps Find New Reserves In Mature Basins

The oil industry’s history demonstrates clearly that new plays and prospects have long been found in mature basins that were thought to be well on the way to being squeezed dry. Through the acquisition of new data, developing new concepts and coming up with fresh interpretations, long-producing basins around the world from the North Sea to Malaysia have continued to reveal new riches...

August 8, 2016

Northern Shield Identifies High Quality VTEM Targets at Séquoi

Northern Shield Resources announced the results of the interpretation and modelling of the VTEM survey from the Séquoi Property in the Labrador Trough of Quebec . Séquoi is owned 100% by Northern Shield and is being explored for Noril'sk style Ni-Cu-PGE massive sulphides. After geophysical modelling and interpretation of the VTEM data from Séquoi, six VTEM anomalies of significant interest have been identified...

August 3, 2016

Rio Tinto tailors big data drive to copper

Rio Tinto will put the weight of an exploration big data push and its newly-formed Growth and Innovation group behind its desire to identify a "tier 1" copper asset. Speaking at the annual Diggers & Dealers conference in Kalgoorlie, Growth and Innovation group executive Stephen McIntosh said Australia was "overdue for a tier 1" mineral discovery of any type...

August 1, 2016

Tetra Tech Awarded $200 Million Navy CLEAN Contract

Tetra Tech announced that it has been awarded a $200 million, single-award contract by Naval Facilities Engineering Command (NAVFAC) Atlantic. Through the Comprehensive Long-term Environmental Action Navy (CLEAN) contract, Tetra Tech will provide environmental engineering support services to installations within the NAVFAC Atlantic Area of Responsibility...

May 3, 2016

NATO Science for Peace and Security (SPS), MODUM Partners announce "Young Scientist Summer School on Sea Dumped Chemical Weapons"

This international project cooperates closely with CHEMSEA (Search and Assessment of Chemical Weapons) Project for and sharing and knowledge transfer...

April 12, 2016

Monday mad rush for gold stocks

Renewed optimism about the outlook for gold saw investors pile back into gold stocks, pushing many stock to 52-week highs in heavy volumes...

April 11, 2016

Medgold Resources: Continues to Expand the Boticas Gold Project, Portugal; Proposes $200,000 Private Placement

Medgold Resources is pleased to announce new assay results from contiguous rock-chip sampling from the Limarinho South zone at its Boticas gold project in Portugal, which include a highlight of 6.0m @ 5.7 g/t Au...

April 8, 2016

De-carbonizing our energy sector

Nuclear energy currently provides around 11 percent of the world's electricity. China, the European Union, the United States, India, Russia, South Korea, and other nations’ have major existing fleets...

April 1, 2016

Follow-Up Drilling Results Indicate Wide Gold Zones at Hendricks Gold Discovery

Gascoyne Resources Limited announced that it has received the final assay results from the 10,000 metre aircore exploration drilling programme...

March 26, 2016

The Oil Market Is Finally Hitting Its Breaking Point

After a significant reduction in investments over the past two years, oil companies can no longer overcome the production declines from legacy wells...

March 15, 2016

N-Sea Expands into the French Offshore Wind Industry

Subsea IMR provider, N-Sea, has signed a letter of intent with CERES Recherches & Expertise Sous-Marine and TechSub Industrie Environement, to provide subsea survey, installation and remediation services to the French offshore wind industry...

March 9, 2016

PDAC 2016 Convention Exceeds 22,000 Attendees

Optimism and opportunity abounded at the PDAC 2016 Convention of The Prospectors & Developers Association of Canada in spite of recent industry challenges...

March 3, 2016

6 Alpha Launches EOD Contracting Division

6 Alpha Associates, a specialist risk consultancy practice, with expertise in the assessment and management of unexploded ordnance, has launched a dedicated explosive ordnance disposal division...

Geotech’s VTEM: detecting vanadium and graphite deposits with EM methods

by Carmela Burns on July 19, 2012 technology

The recent rush to find graphite and vanadium deposits to satisfy potential demand in green energy applications is reigniting airborne electromagnetic (EM) methods as highly effective exploration tools.

Graphite and vanadium are both commonly used in steelmaking and both are finding new, high-tech applications such as lithium-ion and vanadium-redox batteries, wind and solar power. In some cases the two materials occur together in nature, allowing geophysicists to use the highly conductive graphite to lead to the more subtle vanadium that can be bound by several different minerals.

As is the case for many accessory minerals, there are no direct geophysical methods for detecting minerals containing vanadium, says Alexander Prikhodko, senior geophysicist with Geotech. Geophysical techniques are able to reflect only indirect indications, or “symptoms”, of the metal and the factors that control its deposition.

Where there is a graphite association, he says, EM methods are highly effective in exploration for vanadium. Tintaniferous magnetite, a common vanadium host, also provides an EM response.

At Triple Nine Resources’ Four Corners iron ore-titanium-vanadium property in Newfoundland, for example, a 2011 helicopter borne VTEM survey conducted by Geotech over newly staked claims extended one high intensity magnetic anomaly and discovered three new ones. The targets occur along (and in close proximity to) the Cabot Fault Zone, part of a globally significant, deep penetrating structure that is the likely source for the mineralized fluids at the Four Corners Property.

Follow-up drilling on the property’s Keating Hill anomaly, which the VTEM survey suggests has double the strike length than that originally outlined, confirmed significant concentrations of all three metals down to a maximum vertical depth of 590 m, including a weighted average grade of 20% Fe2O3 T (total iron), 3.5% titanium oxide (TiO2) and 0.10% vanadium pentoxide (V2O5).

Furthermore, prospecting along the largest of the four anomalies, the Four Corners MAG anomaly (FCMA), confirmed widespread enrichments of titanium – vanadium – magnetite mineralization with assays of up to 48.8%  Fe2O3, 12.5% TiO2 and 0.31% V2O5. FCMA has a strike length of at least 4.5 km and a width of is 1.5 km and appears to be part of a large mineralized system that will require more follow up.

The high conductivity of graphite lends itself well to electromagnetic surveys, and there are a number of airborne electromagnetic systems that are being used successfully for vanadium and graphite exploration, including Fugro's HELITEM (time domain) and DIGHEM (frequency domain) systems and Geotech’s VTEM system. Each system has its unique strengths.

Prikhodko notes that there is no single technical characteristic that identifies an EM system as the best for a particular exploration task including finding vanadium deposits. Instead, the electronical and mechanical attributes of the system work together to provide an integrated solution. Just as the loudest singer is not necessarily the best, the EM system with the most powerful transmitter is not necessarily the most appropriate for targeted exploration.  The “loudness” of a system must be balanced with timbre, clarity of sound and precision of note, he says.

According to Prikhodko, one of the key technical advantages of Geotech’s VTEM system is the balance between high power and sensitivity. “Balance is achieved through complex engineering, noise reduction in very wide broadband and optimization of the transmitter’s current wave form to use as much of the helicopter’s spare electrical power as possible,” he says.

In this way, VTEM can detect and discriminate between low to excellent conductors using a low base frequency, long pulse width, system calibration and a B-Field derived from integrating data collected at 96 kHz over the entire waveform.

Geotech’s continual development of their technologies has included extensive GX programming within the Geosoft platform to build a highly specialized and integrated solution for quality control, processing, visualizing and presenting VTEM results.  “ We utilize  Geosoft for QC procedures, data processing,  maps creation,  parameters calculations and resistivity depth imaging,” said Prikhodko.“ Geotech geophysicists and processors have developed lots of special GXs to accommodate our workflows.”

For vanadium and graphite exploration, and especially when the two materials occur together, EM methods are proving to have the right combination of deep penetration, sensitivity, and spatial and conductance discrimination to detect future deposits of these strategic resources.