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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...

Seeing the shades of grey in 3D inversion

by Virginia Heffernan on June 4, 2012 technology

Using 3D models of the subsurface derived from geophysical data is standard practise for guiding exploration in the petroleum industry and has the potential to improve success rates for mineral explorers.

But because geophysical inversion models can provide the same response for different geological scenarios, they can introduce ambiguity into the resulting interpretation. The latest thinking, and technology, has focused on the key factors required to generate 3D models with greater ease and confidence, making their output more reliable and informative as an aid for mineral exploration.

Topping the list of requirements is the ability to integrate as many constraints as possible - including gravity and magnetic data, surface geology and borehole logs. The resulting complete earth model is more likely to pick up nuances in physical rock properties and provide a truer rendering of what lies beneath the surface.

“We’ve got to start thinking about the shades of grey,” says Dr. Bill Morris, a 3D modelling expert and professor at McMaster University’s School of Geography and Earth Sciences. With direct detection of ore bodies becoming increasingly rare, geoscientists must “get past the bull’s eye approach and, instead, put all our little clues together to get the big clue,” he says. “We need to have more physical property databases, and we need to be able to link physical property variations to geological reality.”

Eventually, as the number of constraints in inversion models increases, geoscientists will be able to map regions of alteration in proximity to orebodies,Morris and his co-authors predict in a recent paper entitled Integrating geological constraints in geophysical models.

From the technology side, the ability to rapidly create, modify, iterate and combine data within project timelines is essential for making geophysical modelling a more practical and reliable aid for exploration. 

The challenge has been developing lighter workflows for what are currently resource and time intensive modelling algorithms.  While 3D inversions using voxel earth models have been available for years, it takes highly trained specialists with powerful computing capacity to produce them.  And the associated workflow required to define and introduce constraints is time-consuming.

The newest inversion modelling technology, introduced by Geosoft in April, was developed under the lead of modelling expert Dr. Robert Ellis, a co-founder of the UBC Geophysical Inversion Facility, and relied on input from industry collaborators to address these challenges.  Usability and “lighter workflows” were the primary drivers in the development of VOXI, which also harnesses cloud computing to allow geophysicists to work with ever-larger models.

In a recent post in the Exploring with Data blog, Chief Technologist Ian MacLeod tells the development story behind the cloud-based VOXI Earth Modelling service that took over three years and required the work of 29 people to create. VOXI provides tools for making interpretation of 3D inversion models faster,more accurate and accessible to a broader range of explorers, and includes a new Magnetization Vector Inversion (MVI) technique.

The service allows geoscientists to convert magnetic and gravity data directly into 3D models that can be integrated with other project data. Better yet,they can do this in the cloud using Microsoft’s Azure cloud computing platform rather than relying on the limited processing power of their own computers.“Building a multi-core cloud-based algorithm is very different from building a program that runs on a workstation or local cluster,” says MacLeod. “The effort to re-engineer VOXI for Azure took us most of a year to get right.”

Making the software usable is a challenge in its own right, notes MacLeod in his post. “We worked very hard with our collaborators over two years to design and improve the VOXI interface,” he says, “so that everything would work as smoothly as possible and fit within an explorer's natural workflow.”

Speed in generating 3D inversions is one of the essential ingredients that will allow geoscientists to use these tools routinely, enabling them to iteratively improve models as they add constraints and learn more about their projects.

One early adopter says a modeling exercise that took him four hours to complete using his current desktop modelling program, took just two minutes using the VOXI service.

The future of mineral exploration using 3Dinversion models looks even brighter under the lens of better and more plentiful data sets that can be used to constrain inversions, especially borehole geophysical data.

“We have a whole suite of new tools that are giving us information that we have never received before,” say Morris. “The other big key is that we are now seeing integrated geological and geophysical model development platforms.”

This will allow geoscientists to move more comfortably between the three main geophysical models (discrete body, lithologic surface and voxel mesh inversion), incorporating elements of each one into a fully constrained inversion.

“The systematic use and development of 3D models for each mining camp will certainly lead to the discovery of new resources in many of the older mining camps,” he predicts.

Related Articles:
Introduction of VOXI Earth Modelling