Mineral Exploration Trends & Technology
Emmerson Resources drilling in Australia’s Tennant Creek Mineral Field
The
main indicator of the situation in levels of exploration activity is
the amount of drilling metres that have been completed, and those that
have been budgeted for in the subsequent year. Currently, the outlook is
mixed. A lot of concern and reining in of costs in mid to late-2012 on
the back of a negative mood in Australia and uncertainty with regard to
government action in other countries such as Mongolia and Argentina,
along with struggling commodity prices, has in early 2013 been replaced
by a somewhat more optimistic outlook, a metals and ores price recovery
and a feeling that this may just have been a dip in otherwise continued
growth.
In a November 2012 interview with IM,
Francis McGuire, President and CEO at Major Drilling, one of the
leading global mineral exploration drilling contractors said that the
2012 downturn was nothing like 2008 in depth and effect: “Many
companies in 2011 drilled extra metres beyond what they had budgeted for
but in 2012 they stuck to their original drilling plans. Much of this
work is still from the mid-cap to the largest mining groups, with
juniors still finding it very difficult with regard to raising finance;
though this does not reflect any lack of need for new deposits. If
anything this trend is worrying as it will have a lag in terms of new
development not catching up with projected commodity demand.”
A
lot of the focus of the major groups is replacing resources that are
depleting at the mature mines. While in the 1980s, a lot of near surface
deposits were located using aerial surveys, more and more the focus is
on delineating deeper deposits. The average holes 7 to 8 years ago were
in the 500-600 m range – now companies want holes drilled from 1,200 to
2,000 m and beyond. High altitude drilling is also on the increase,
with the associated logistical headaches and narrow operational windows.
A mixed 2012
The
uncertainty in 2012 was reflected by comments made on the industry by
leading drilling groups Major Drilling, Energold, Boart Drilling
Services and Layne Christensen. In its statement and review for the
quarter ending October 31 2012, Major Drilling stated: “As expected
during the quarter, two general factors contributed to a decline in
revenue. Many mining companies did not extend their activities beyond
their original budgets. Last year, most senior companies continued their
drilling efforts well into November and December. While revenue from
senior and intermediate companies actually increased year-over-year by
some $20 million, we saw a decline in our activities with junior mining
companies. In fact, 78% of our revenue during the quarter came from
senior and intermediate customers. Many of these projects are slated to
continue and are expected to create a solid base for our operations in
calendar 2013…..during the quarter, four branches faced specific
challenges. Australia had many projects cancelled due to high costs,
the high Australian dollar and new mining taxes. Mongolia and Argentina
were affected by political uncertainty, although both started to recover
somewhat late in the quarter. Finally, Mexico had many projects
delayed or cancelled as this region has a larger proportion of junior
customers.”
Boart Longyear’s new LX11 mineral exploration rig
However,
the group added: “Looking forward, if customers go ahead with their
stated plans, we see consistent levels of activity coming in calendar
2013 from both the senior and intermediate mining houses as well as
junior companies with projects in development. The bidding activity in
most regions has been very similar to last year with the exceptions of
Australia and Argentina…based on current customer plans, we expect
demand for specialised drilling to continue in the year ahead.
Specialised drilling continues to form the cornerstone of our corporate
strategy. Although there has been a recent increase in junior financing
activity, we have not yet seen any significant increase in their
activity levels.”
For the same period, Energold
reported that: “Metres drilled during the third quarter decreased over
the comparable quarter in 2011 as a result of the challenging capital
markets, particularly in the junior mining sector.” Its Mineral Division
drilled 92,300 m in the quarter, a 46% decrease from the comparable
quarter in 2011, while average revenue per metre was $192 in the first
nine months of 2012 compared to $174 in 2011: “Management anticipates
this to trend lower as excess rig capacity in the markets may lead to
lower competitive bids. Gross margin percentage is historically tied to
the business mix of frontier-style drilling and established brownfield
drill programs, with the latter moving the average revenue per metre
lower. With a higher percentage of programs dedicated to majors’
brownfields projects during the third quarter, gross margin was 28%,
compared to 31% in the comparable period 2011.” As of September 30,
2012, Energold had a total of 130 mineral exploration rigs, with Mexico,
the Caribbean, and Central America accounting for over 52% of the
metres drilled for the third quarter of 2012 with 45 rigs in the region,
followed in importance by South America and Africa.
Layne’s
Christensen’s Mineral Exploration Division revenues decreased 15% in
the quarter, with the company stating this was: “primarily in Australia
and Africa, reflecting reduced mine exploration activities by our
clients…global economic and credit uncertainty produced a decline in
mineral exploration activity in Australia and Africa, the result of
which was lower quarterly revenues at our Mineral Exploration business.”
Broad trends
The
trends in types of activity are clear. Globally, drilling customers
want to go much deeper and with declining grades, much higher tonnages
need to be defined with drilling programmes. Associated with this trend
is a major step change in required equipment, skills and associated
training, especially above the 800-900 m level. At the same time, the
largest equipment OEMs in some cases don’t want to make highly
specialised deep hole drills because the market remains smaller and they
don’t represent the same return on investment, as it is the drilling
contractor that will see the greatest benefit in deeper drilling as
opposed to the equipment manufacturer. But the contractors traditionally
would rather buy-in drilling technology than have to invest in
development themselves as this is clearly not their core business. As an
example, Major Drilling used to own the manufacturer UDR, but sold it
to Sandvik as it was not a core business – and the associated added
plant and sales workforce as well as plant operational cost were hard to
justify during downturns in drilling activity.
All
of the drilling contractor majors would like a 2,000 m plus ‘standard’
drill as this doesn’t currently exist in the market, and are working
with key manufacturers on making this a reality. But there are also
smaller drill rig players, for whom a $10 million order is significant,
who are more willing to make the necessary investments in more
specialised rigs, though they do not have access to the same
software/design and engineering resources.. And while it may be a
smaller business for the largest OEMs for now, it is the main drilling
services companies that have the main purchasing power going forward so
their preferences will ultimately drive technology development.
As
stated, the challenge is that contractors and their customers want the
specialised deep hole rigs but they also want them to be
portable/flyable to reach high altitude and very remote sites. But the
rigs capable of deeper drilling are also heavier. There is no possible
compromise – either deep hole drills have to get lighter or many of the
planned drilling programmes will be very expensive as they will involve
multiple helicopter trips of separate drill components.
Major
Drilling points out that is the first drilling group to widely adopt
lighter drill rods in the form of Boart V-Wall Coring Rods; and is
considering standardising by adopting this type of technology across the
board, as using a mix of rods makes logistics/inventory more
complicated. At the same time, these new rod designs are 30% more
expensive, so a move like this would have to be justified in its
customer charges. John Nielson, global products manager, Boart Longyear
told IM: “V-Wall rods offer up to 30% weight
savings in each rod. They allow an existing drill to go deeper due to
the lighter weight of the drill string. For example, a drill rated for
2,500 m would be able to manage a 3,250 m drill string using V-Wall.
Also, in operations without rod handling equipment, the weight savings
of V-Wall rods keep drillers and helpers lifting less weight, thus
reducing fatigue. If the bore hole requires wedging, VWall is
recommended because it is more flexible and is best suited to these
deviated hole applications.”
On the drilling bit
side, even though technology in materials and designs has increased,
there is still significant price pressure due to the levels of
competition and the fact that the market is still dominated by customer
preference. In the past, the bit costs used to account for about 10% of a
total drilling programme cost; now it is closer to 4%.
New drilling technology
Addressing
the issue of more portable, deeper hole rigs, Boart Longyear has its
LF130F model, which “is the only rig in its class that offers large
diameter PQ drilling capabilities” and is one of the largest
heliportable (breaks down into nine modules) rigs currently available,
with features such as balanced lifting points and quick-connect
hydraulic couplings to ensure quick and reliable setup and breakdown. It
is rated to 2,640 m in a fluid filled hole with BRQ/BQTK core and to
1,510 m with NQ core. Justin Warren, Senior Global Products Manager,
Boart Longyear told IM: “The LF130F can reliably and consistently
deliver these depths while using V-Wall rods, all with the flexibility
that a flyable package provides. We also have two other models which are
rated to exceed 2,000m, the LX16 multipurpose drill and the LF230
surface coring drill. We also plan on enhancing our deep hole drill
offering in the future.”
The latest news from the
group, and new for PDAC 2013, is the introduction of the LX11, “an
economical multipurpose drilling rig for the mineral exploration
market.” The new LX11 multipurpose drilling rig features “improved
safety mechanisms, track mounting, a smaller footprint, and an overall
lower cost of ownership.” The medium-size LX11 is an addition to the
existing line of Boart Longyear multipurpose drilling rigs, the LX6 and
the LX16. With capabilities to perform reverse circulation (RC) and
diamond core drilling, the LX11 allows exploration drillers to use one
drill rig when encountering various ground conditions. This lowers
initial capital investment and limits the costly downtime required to
switch rigs to match drilling conditions. “The multipurpose LX11
drilling rig is the culmination of many years of hands-on experience,
advanced engineering and field testing,” said Warren. “The
versatility of the LX11 allows drilling contractors the ability to
supplement the roles of multiple rigs with the simplicity of one, saving
on equipment costs.” The LX11 can reach depths of 1,450 m using NQ
rods via diamond drilling and depths of 325 m with 114 mm rods via RC
drilling. A 7.2 m mast and a top drive head allow 6m rods to be pulled
under the head for increased productivity. A top drive single rotary
drill head features 1,200 rpm and a maximum torque of 7.8 kNm at 100
rpm.
Several safety features are incorporated into
the LX11, beginning with a strategically placed control panel for ideal
visibility, a remote control for driving the rig at a safe distance and
an interlocked safety cage to protect drillers from the rotating drill
string. Lastly, the LX11 can be equipped with a rod handler for safe and
efficient handling of both RC and diamond coring rods. The small
footprint of the LX11 allows for easier site access and
manoeuverability. It is also designed to fit into a 12 m high cubic
container, making it more economical to ship to remote locations. Track
mounting increases the mobility of the LX11 with the ability to handle
steeper grades and lowers environmental impact.
Finally,
in bits, the company recently launched the GTUMX diamond coring bit as
the latest addition to the Ultramatrix (UMX) line. The GTUMX is designed
for shallow holes and conventional drilling for both exploration and
geo-technical applications. The ability to drill faster with high
penetration rates and to outperform existing bit technology in a wide
range of ground formations makes the GTUMX “ideal for customers seeking
an affordable alternative” to their current bit selection.
“Boart
Longyear is excited to introduce the GTUMX diamond core bits into the
marketplace, especially South Africa,” said Matthew Baird, Global
Product Manager for Boart Longyear. “The GTUMX bits are ideal for
shallow holes and conventional drilling. This allows our customers to be
very competitive with a bit of true value at a reasonable price.” Boart
Longyear will launch an AXT size GTUMX bit first in the South Africa
region. This will be followed by additional bit size releases and
expansion into the Asia Pacific, Europe and Latin America regions.
GTUMX diamond coring bits feature the Boart Longyear UMX formula. UMX
bits use an advanced metallurgical formula that is impregnated with
large synthetic diamonds. The formula optimises high penetration
capabilities with longer bit life and allows the GTUMX to turn easily
from one ground formation to another.
The GTUMX also
features the unique Razorcut design on the face of the bit. This speeds
up exposure of the diamonds and enables the bit to begin cutting right
out of the box. The wide tapered waterways dramatically improve surface
flushing and cutting while reducing wear on the inner-diameter of the
bit, particularly in broken, abrasive conditions.
The control panel for Sandvik’s new DE130x
Sandvik’s
DE100 series of compact core drills for surface and underground
exploration applications now includes a fully ATEX certified rig, the
DE130x. The design is based on Sandvik’s proven DE130 core drill. Its
modular design together with a depth capacity of 815 m at N-size, a feed
force of 4.7 t, a pull force of 6.3 t, makes the DE130x “a truly
capable exploration drill rig” states the company. The DE130x features a
completely redesigned power unit which monitors; hydraulic oil
temperature, electric motor temperature and incoming power. Intrinsic
safety circuits are also included. The power unit is prepared for
400-1,140v of incoming power and the whole drill unit is certified and
designed for maximum surface temperature of +150°C (class T4). In
accordance with ATEX standards in Europe, some of the parts featured on
the standard DE130 have been replaced by steel parts. Additional
features from the standard DE130 include an extra gauge for rod holder
surveillance on the control panel, and a wire emergency stop on the feed
boom for increased safety. George Tophinke, Sandvik Mining’s Global
Exploration Equipment Manager, comments: “Historically the DE100 series
rigs have been very successful for Sandvik and are in operation all
around the globe, now with the expanding coal markets we saw the need to
expand our offering to include a certified version of these drills,
also in line with the important ongoing efforts Sandvik is doing with
integrating EHS issue into their products.” ATEX consists of two EU
directives (one for the manufacturer and one for the user of the
equipment) describing what equipment and work environment are allowed in
an environment with an explosive atmosphere. The DE130x is a fully
certified exploration drill rig for underground coal applications
according to these latest ATEX standards in Europe.
The new T685X from Schramm
Schramm
has announced the introduction of its new T685EX model to its
exploration drill rig product line. The Schramm T685EX is a heavy duty
drill rig specifically designed for mineral exploration applications. A
high capacity top head, sampling equipment, power breakout and automated
pipe handling systems make it suited to a range of RC drilling
programmes. The T685EX is offered in both track and truck mounting to
offer the contractor optimum mobility to suit particular application
needs. Schramm states: “We understand that exploration programs have
varying depth requirements, so the T685EX is available in hoist packages
ranging from 18,180 kg to 40,909 kg.” The T685EX features increased
engine horsepower and compressor capacity and is equipped with a V-Pack
cooling system for increased efficiency. The MTU 12V- 2000, 905 hp
engine provides power required for all hydraulic systems and a high
capacity Sullair compressor produces 38 m3/min at 34.5 bar. A mechanical
clutch is provided to disengage the air compressor to facilitate a cold
engine start and to conserve power and fuel when the compressor is not
required. The compressor package also includes Schramm’s patented
air-CONTROL System which monitors cooling system temperature and
compressor volume requirements, matching fan speed and the compressor
inlet valve providing maximum power efficiency. For added safety,
galvanised steel hose whip socks are fitted to all 50.8 mm and larger
hoses containing air, including the cuttings discharge hose. The top
head drive is designed to provide drilling speed and torque
characteristics required for tri-cone rotary bits or down-thehole
hammers. Low speed, high torque hydraulic motors provide a wide torque
and speed range at high overall mechanical efficiency levels while
spindle thrust forces are handled by large tapered roller bearings
mounted in heavy fabricated steel housing.
The
tracked carrier system includes a tramming station located at the front
left-hand corner of the machine for operator convenience. The tramming
station includes an adjustable height seat, a radio remote tramming
control and a back-up manual hydraulic tramming system. The radio system
allows for remote tramming when loading and unloading from transport
trailers.
A variety of automated pipe handling
systems are available to insure the safest possible operation. These
systems provide hands-free operation for loading and unloading of drill
rods directly to the top head. They mount on the right-hand side of the
mast, opposite the operator and lift rods from the side rack, remote
racks or a support truck. To further enhance pipe handling automation, a
hands-free, full breakout and make-up system eliminates the need for
conventional wrenches or tongs. A hydraulic sliding holding wrench is
supplied to support the drill rods in the table. A light weight hinge
mounted guard is also supplied to prevent contact with the rotating
drill string while an exploration jib boom, auxiliary and sandline
winches round out the T685EX pipe handling package.
The
T685EX is factory-equipped with side inlet and discharge swivels,
abrasion resistant discharge hose and plumbing, swing-arm mounted
cyclone and wet splitter systems to meet all RC requirements. Assorted
water and foam injection packages are available and can be combined with
on-board water tanks and mist type dust suppression systems.
Coreboss
has announced the delivery of its first F14T track-mounted surface
coring drill. GDA Servicios Mineros of Chihuahua Mexico has a large
drilling contract that was expected to commence by the end of January
2013. The hydraulic Coreboss drill is powered by a Cummins diesel power
pack and is transported by a remote control module. Both the locomotion
and drilling functions are handled off the same power unit. The unit can
be set up ready to drill in as little as 30 min, with a fully
integrated drilling platform on board. The drill is capable of drilling
to 1,200 m at NQ sizes. A second drill for Mexico is being built with a
third unit expected to close in the near future.
The new Multitec 9000 from Dando
Dando
Drilling International, the long established UK drilling rig
manufacturer (now part of Energold), has launched a new lightweight,
compact, multipurpose rig for surface mineral exploration. Drilling
techniques performed by the machine include RC, wireline coring and
Rotary Air Blast (RAB). The Dando Multitec 9000 has a pullback of 9,000
kgf, and can also be used for water well, geotechnical and ground source
heat pump (GSHP) drilling applications. As well as its versatility, one
of the main features of the Multitec 9000 is its ability to drill to
great depths in restricted spaces due to the rig’s small footprint and
powerful performance. Other features of the rig include a mast dump to
45°; arm mounted drilling control; on board flush pump; hydraulic winch;
high torque, high speed rotary head with hydraulic side shift and tilt;
hydraulic rod clamps/ breaker. The Multitec 9000 is a new addition to
Dando’s ever-growing range of exploration rigs which includes the Mintec
6,12.8 and 18, and the small, towable Dando Terrier drilling rig.
Drill hole analysis and alignment
A
pioneering mineral exploration technology, which delivers real time
information on rock formations while drilling a hole, has been developed
by the South Australia-based Deep Exploration Technologies Cooperative
Research Centre (DET CRC). Known as the “autonomous shuttle”, a small
sensor and data logger are pumped to the bottom of a drill hole where
they protrudes beyond the diamond drill bit. The shuttle then measures
the properties of the rocks surrounding the hole as the drill rods and
bit are gradually retrieved.
The autonomous shuttle
was designed, built and tested by researchers at Curtin University and
Globaltech (a Perth-based company supplying and developing tools and
technologies for efficient exploration drilling) and has successfully
recorded natural gamma radiation in a test hole, indicating that it
could differentiate between rock types.
The “autonomous shuttle” sensor from DET CRC
“This
means we can cost effectively retrieve real-time data on the rock
formations deep inside the earth,” DET CRC Chief Executive Professor
Richard Hillis said. “The natural gamma sensor used in the successful
trial is the first of several sensors that will be deployed on the
autonomous shuttle. With a suite of sensors, the shuttle could replace
much drill core, saving time and analytical costs and permitting
drilling techniques that are only half the cost of conventional diamond
drilling, at a time when Australian mining is feeling the pinch of high
costs and declining commodity prices.”
Hillis said
the technology had been successfully tested at the DET CRC’s Brukunga
Drilling Research and Training Facility, in the Adelaide Hills, where
new technologies can be tested against a fully cored and logged
reference hole. The facility only recently opened but has already been
the site of several successful field trials of new technologies. Gordon
Stewart of Globaltech, one of the key researchers on the project, said
the conventional process of analysing core from drill holes was
time-consuming and expensive. “Mineral exploration holes are drilled to
obtain information about the rocks at depth in the subsurface. Current
methods require analysis of core or rock cuttings from the hole or they
require the time and expense of mobilising a separate wireline crew to
run sensors in the hole. Since it can be deployed by the drilling crew
to obtain real-time information from a hole without the risk of the hole
collapsing before it is analysed, the autonomous shuttle is a major
international advance and offers significant cost savings.”
Hillis
said the shuttle’s full sensing capability would dramatically increase
productivity by avoiding delays of weeks or sometimes months, when core
is sent to laboratories for analysis. “It will also enable cheaper
existing drilling methods to replace diamond drilling and open the door
for next generation drilling technologies such as downhole motors and
coiled tubing drilling.”
The DHS Azimuth Aligner installed on a Swick drill rig
A
new Azimuth Aligner from Australia’s Downhole Surveys (DHS) addresses
the age old problem of how to align a drill rig quickly, in an
underground environment. Traditionally; pegs, paint lines or flagging
tape have been used to set out an azimuth to which the driller must
align his rig. This is both time consuming and inaccurate resulting in
errors in drill collar azimuth alignment. The Azimuth Aligner utilises
the latest military grade North Seeking Gyro technology to rapidly and
accurately determine true north. After just 25 minutes the Azimuth
Aligner will provide an azimuth relative to true north. By placing the
device onto a drill rod at collaring, the driller is now able to
accurately and quickly align the drill rig to a given azimuth and dip.
DHS states: “For the first time in the industry the Azimuth Aligner
solves the problem of rig alignment underground and to a precision of
0.2 degrees.” A 6.5 in full-colour touch screen provides the user with
live high quality numerical and pictorial representation of the azimuth,
pitch (dip) and roll angles as the drill rig is manoeuvring.
Two
Azimuth Aligners are currently onsite at Newmont’s Jundee underground
gold mine site in Western Australia aligning five Swick MCR drill rigs,
conducting 40 setups per month. A significant reduction in setup time
has been reported. Traditional setup time had been between 1.5 to 2
hours and required several checks after setup. Setup time has been
reduced to just 5 minutes and according to DHS, productivity has
increased and additional metres are being drilled per month.
On
the surface, with diamond and RC drill rigs often difficult to
manoeuvre and align to a collar setup, the Azimuth Aligner can be
mounted to the drill mast and the display mounted in the cab, displaying
azimuth and assisting in the drill rig when reversing and manoeuvring
to the collar position. As the hydraulic legs are activated to level and
raise the drill rig, it continually outputs the azimuth and
dip allowing the driller to position accurately. In addition the Azimuth
Aligner continually displays the dip reading.
Company developments
Adrok,
the Scottish “virtual drilling’ technology” development company has
announced expansion plans which will see the company invest almost
£1.8million in new staff and equipment over the next two years.
Edinburghbased Adrok has been awarded a Scottish Enterprise Regional
Selective Assistance (RSA) grant of £180,000 to support the company’s
investment plans. By 2015, Adrok is aiming to hire 15 new staff in
Edinburgh, increase the number of crews and equipment, and further
improve technology to boost its international offering.
Adrok
are creators of the Atomic Dielectric Resonance (ADR) scanner, which
uses radiowaves and microwaves to locate, identify and map subsurface
natural resources to help exploration and production companies decide
where to drill for resource deposits. The company states: “Unlike
traditional seismic technologies, the portability of the ADR scanner
makes exploring extreme environments such as glaciers or mountains
possible. It is set to transform industries also looking for greener and
cheaper ways to mine and explore for minerals, hydrocarbons and
commodities.”
In addition to the Edinburgh expansion
plans, Adrok has been building its international presence having set up a
base in Perth, Australia this year. A base in Houston, Texas will open
early 2013. Gordon Stove, Managing Director of Adrok said: “We have had
significant growth due to business wins, as well as our investment in
Australia and North America and we are now in a great position to invest
further in the future of our company. This grant provides the
assistance we need to build the business and ensure we can continue to
service our growing client base. As a business, we want to change the
way oil & gas companies and mining companies think about and
experience exploration and these investment plans are the next step in
what we see as a new wave for the industry.”
Donald
Campbell, Adrok’s Scottish Enterprise Account Manager said, “Adrok is an
excellent example of a Scottish company with fantastic international
growth potential and we are pleased that this grant can help them toward
achieving their ambitions. Regional Selective Assistance is one of the
ways in which we help companies to continue to invest in the current
climate. It helps us create the right environment for companies who want
to grow their businesses in Scotland, and in doing so to create
much-needed jobs and positive economicgrowth.”
Geoplano
and Cabo Drilling have signed a cooperation agreement to support each
other’s efforts in offering expanded geological services to mineral
exploration and mining companies active in the Iberian Peninsula and
select countries of North Africa. “Aligning Cabo Drilling’s experience
with core and reverse circulation drilling with Geoplano’s geotechnical
expertise is a natural fit as our sub-surface exploration, engineering
and sampling services are complimentary,” stated Terry Aimone, Cabo
Drilling’s General Manager in Europe. “Together we can provide a full
set of services to the exploration and mining industry. I look forward
to offering this expanded level of service in this market area and
beyond.” In 2001, after a change in the ownership structure, Geoplano’s
name was modified to Geoplano Aherne – Geotechnical Consultants, marking
the beginning of what it calls “a renovation cycle.” This has been
marked by the strengthening of technical facilities,
internationalisation to Eastern Europe and Africa, and an investment in
areas such as groundwater works and environmental assessment. Cabo
Drilling is a drilling services company that provides mining specialty
drilling services throughout North America and has strategic
subsidiaries in South America, the Balkan States and the global Cabo
Drilling (International).
DMT, the Natural Resources
Division of the TÜV NORD Group, is implementing a uniform branding
policy for its subsidiaries around the world. As part of a series of
measures to strengthen the DMT brand, Petrologic Geophysical Services
has been renamed DMT Petrologic with effect from 2013. Petrologic is
well established in the international market for seismic special
processing while DMT has been active in the field of natural resources
exploration ever since Ludger Mintrop developed the seismic exploration
method over 100 years ago.
Mining software solutions
group, MICROMINE, recently announced that it is expanding its portfolio
of world-class exploration and mining consulting services. MICROMINE’s
international consulting arm, Micromine Consulting Services (MCS) helps
mineral resource companies to drive operational efficiencies and develop
resource reserve potential through “high-quality geological and mining
consulting services.” A special launch event for MCS’s Exploration
Services was held in December 2012. Leading MICROMINE’s team at Mines
and Money London is James Hogg, CEO of Europe, the Middle East and
Africa who oversees the organisation’s business development and
strategic growth across EMEA markets: “Our growing team of international
consulting geologists, engineers and support staff deliver unrivalled
customised early stage exploration solutions that are supported by
MICROMINE’s award-winning in-house technology. We have continued to
expand our global consulting services across all stages of the
exploration process ranging from desk studies, grass-roots exploration
and resource development, to production, data analysis, optimisation and
tailings regeneration, across all commodities and deposit types.”
Offerings include a new version of its flagship geological exploration
and mine design software, Micromine, its geological data management
solution, Geobank, as well as its new geological field logging solution,
Geobank Mobile.
Diamond drilling solutions major
Fordia recently received the Grand Prix québécois de la qualité for its
management and overall performance at an Awards Ceremony organised by
the Quebec Society for Quality (QSQ). According to the QSQ, Fordia’s
teamwork and good business practices are what set it apart and make it
one of the best businesses in Quebec. Its brand and the quality of its
products are increasingly recognised throughout the world. In 2012, the
company opened new offices in Colombia and South Africa, as well as
distribution outlets in China and Mongolia.
Exploration software
Screenshot from Maptek Eureka system
Maptek
Eureka is the latest in a line of original solutions from mining
technology developer Maptek, and is aimed at “giving miners an
intelligent window into their data.”Maptek CEO Barry Henderson states
that Maptek had developed Eureka to help explorers satisfy the massive
global demand for minerals: “In the next 30-50 years, the world will
consume as much copper as has been mined historically. The same applies
to iron ore and other metals.” Allowing information to be analysed and
exploited at a very large scale, Maptek believes that Eureka represents a
paradigm shift in the way exploration data is used.
“A
few years ago, an exploration company asked us for help in viewing
seismic sections. Our software was 3D, the sections were in 2D and they
really needed to see where those sections were in 3D space. Once we’d
solved that problem, we realised that we could bring in other types of
data and this was the catalyst for developing Eureka,’ Henderson
explained.
Eureka allows large datasets with millions
of points such as airborne magnetic and radiometric surveys, space
shuttle topography data and imagery to be viewed in a single 3D
environment. Interacting with the spatially located data in context
allows geologist to analyse the relationships, and confirm their
intuition.
The group states that Eureka offers much
more than a viewing platform, as intelligent tools convert seismic time
data to depth without ignoring the important drillhole information.
Powerful, modern graphics allow geologists to “see the big picture over
vast regions”, and also explore local targets in detail.
The
Eureka Field tablet offers tabular data entry via drop-down list,
hand-writing recognition or virtual keyboard. Logged data can be
synchronised between the tablet and Eureka desktop application in real
time using Wi-Fi or 3G connections. The company concludes: “Maptek
Eureka will ensure explorationists make full use of data from expensive
drilling and geophysical programs and allow serious explorers to achieve
their goals.”
At the recent Explo Abitibi event in
Rouyn-Noranda, Quebec, Photonic Knowledge launched a new software
package called PKLOGGER, which it believes could revolutionise the
industry. President Eric Roberge stated that mining and exploration
companies will be able to significantly increase their productivity by
obtaining faster results, while at the same time helping their
geologists in objective data logging and management. The software makes
it simpler and easier to record and analyse core samples and can
digitally display what is physically present on a core logging table.
One of the advantages of using PK-LOGGER is that there is no need for
geologists to use a measuring tape because the exact measurements and
other data are displayed under the cursor in real time. “Even if a
geologist is only working with a few boxes of core samples at a time,
they will always be able to see the greater geological context
represented by current samples thanks to an image of the entire drill
core.” Once the work is completed, geologists can export the data in CSV
format to make the information easily transferable to other drill core
logging software applications. The company says it allows for a more
objective creation and maintenance of drill core logs and with the click
of a mouse, managers and geologists can see the greater geological
context, through a high resolution image of the core sample without
having to physically move the core sample boxes.
In
seismic survey software, Acceleware recently announced that DownUnder
GeoSolutions, a leading geosciences company, had selected its Reverse
Time Migration library, AxRTM, to provide customers with “leadingedge
seismic depth imaging services.” DownUnder GeoSolutions will integrate
AxRTM into its DUG Insight geophysical software platform. The resulting
state-of-the-art depth imaging solution is “purpose-built for the
accurate mapping of complex geological subsurface structures.” In
addition to providing customers with reverse time migration depth
imaging services, DownUnder GeoSolutions will be offering the integrated
DUG Insight RTM to its software customers worldwide, under a sublicense
agreement with Acceleware.
“AxRTM leads the industry
in computing performance and image quality. The enhanced TTI stability
mode, high quality imaging condition, advanced noise removal and new
amplitude correction produce images of exceptional clarity and accuracy
in areas with complex geology,” said Matthew Lamont, Managing Director
of DownUnder GeoSolutions. “The unique API provides us with the
flexibility to integrate the library into our existing depth imaging
platform to provide our customers with the high quality images they have
come to expect from us.”
Launched in 2008, AxRTM is
an advanced prestack two-way wave equation migration library with VTI
and TTI anisotropy capabilities. Supporting both GPU and multi-core CPU
clusters, AxRTM is described as “a high-level library offering an
optimised computational grid, flexible and optimised I/O solutions and
efficient scaling for large volumes.
A Mira Geoscience model from the Mount Dore project
Mira
Geoscience provides specialised software and consulting services in 3D
geological modelling, geophysical inversion and interpretation,
interpretive drillhole targeting, and geotechnical hazard evaluation. It
also offers data management technology and services as a foundation for
client modelling needs. The group told IM: “In the deep-search and
under-cover modern exploration context, integration of 3D structural
modelling, constrained geophysical inversion, and expertsystem targeting
is required to deliver optimum drillhole targets. In geotechnical
hazard evaluation, integration of 3D geological and rock mass models
with 4D mine geometry, stress, and microseismicity data yields the
proven potential to forecast the evolution of groundfall hazard in
mining.”
An example project was the assessment of the
mineral prospectivity of the Mount Dore corridor. The Mount Dore
project area is a 175km x 70km block located immediately south of
Cloncurry, Queensland, Australia. It is dominated by copper, gold and
iron oxide mineralisation across a strike length of 150km. The area
hosts significant current, past and future copper-gold producers such as
Osborne, Mount Elliott/Swan, Mount Dore, Selwyn, Kuridala/Hampden and
Greenmount. A detailed 3D prospectivity analysis was completed as part
of a larger Geological Survey of Queensland (NWQNEP) study. Mira’s GOCAD
Mining Suite was used to construct the geological model, geophysical
inversion, rock property modelling and quantitative targeting. The
methodology included: data compilation (geology, geophysics, rock
properties), geological model construction, rock property analysis,
constrained geophysical inversion, creation of a 3D pseudo-facies model,
weights-of-evidence targeting, analysis and review.
GOCAD
Mining Suite is a mining-customised version of GOCAD designed by Mira
Geoscience for mineral exploration and geotechnical hazard assessment.
It enables precise structural modelling, surface (wireframe)
construction, stratigraphic and regular block modelling, and
geostatistics. Add-on modules provide several 3D geological modelling
environments, natural connections to geologically-constrained
geophysical forward modelling and inversion, multi-disciplinary 3D
exploration targeting, exploratory and geochemical data analysis, and
geotechnical hazard estimation and monitoring. GOCAD was first
developed for the petroleum industry by Paradigm, and leverages
significant oil and gas R&D investment. Mira customised it for the
mining industry with add-on modules.
Project case studies
Emmerson
Resources is a junior explorer focusing on the Tennant Creek Mineral
Field (TCMF) in Australia’s Northern Territory. It is using innovative
exploration techniques to target the next generation of deposits in
historically one of the highest grade goldfields in the country. The
company has made recent gold and copper discoveries at Monitor and
Goanna. These are located east and west along strike of the historical
Gecko copper mine within the Gecko Structural Corridor, and have both
reported bonanza gold (>1oz Au) and copper (>8% Cu) drill
intercepts. The new discoveries are hosted in copper-gold-quartz-pyrite
veins within the sub-vertical Gecko shear zone, a new style of
mineralisation for the TCMF which has been uncovered through the
application of new generation electromagnetic system, HeliTEM, from
Fugro Airborne Surveys.
HeliTEM was flown in 2011
over five areas within the TCMF to assist in the search for gold and
copper deposits undercover that have been undetected by previous
exploration. Fugro Airborne Surveys describes HeliTEM as a “new standard
in helicopter borne time-domain EM system. The high power of HeliTEM,
coupled with the low noise at the receiver due to its placement above
and not in the centre of the transmitting loop, ensures the greatest
depth of exploration possible for any AEM system.” HeliTEM combines the
greater horizontal resolution and flexibility of helicopter-borne
time-domain EM systems with proven GEOTEM/MEGATEM technology. Key
attributes include: transmitter dipole moment of 2 million Am2;
measurement of three components (X, Y, Z) of the secondary anomalous
response; full sensitivity on-time measurement; measurement of both
dB/dt and B Field; and access to a full suite of proven processing and
interpretation packages.
Rob Bills, Emmerson’s
Managing Director & CEO, states: “HeliTEM allows us to screen large
areas and reduce the search space to then allow ground based geophysical
tools such as Induced Polarisation (IP). Add to this our geology and
structure in 3D, then directional drilling to test the target.”
Emmerson’s
says its exploration approach is multi-faceted and aims to integrate
some new concepts (as applied to the TCMF deposits) with technology most
appropriate to IOCG deposit types. At the highest level this includes
establishing better prediction methodologies, such as vectors to the
mineralisation through enhancing understanding of the structural and
alteration syndromes of the known mineralisation. These prediction
methodologies are then be coupled with the appropriate detection tools
and applied in a systematic manner across the entire tenement package. A
brownfield example includes reprocessing the existing geophysics
utilising forward and inversion modelling to better define iron oxide
bodies associated with the previously drilled prospects of Troy, Thrace
and Marathon.
The Brandyine craft with Sonic Drill installation on board, used for iron sands exploration in 2011
In
2011, a sonic drill from Sonic Drill Corporation was used for the first
time on a former WWII US Army landing craft – the Brandywine – as an
offshore drilling platform. It was extensively refurbished and is owned
by Seaworks – a group of companies that provide offshore, subsea and
marine vessels, ROVs, equipment and services. Working up to 15 miles off
the coast of New Zealand, the sonic rig was tasked with coring through
iron sands for a feasibility study. In the past, sonic rigs have done
some offshore drilling near Brazil and in the Beaufort Sea but this was a
very new application using the landing craft. To accommodate the drill,
the Brandywine had a “moon pool” cut out of its centre which allowed
the sonic drill to access the ocean beneath and helped to keep it
stable. Initially, the sonic drill had an 86% core recovery rate from
the saturated sands but, eventually, 100% core recovery was reached.
With some holes being drilled to a depth of 76 m, the project used an
SDC 550 sonic rig on tracks with a 50K head – the largest rig made by
the SDC.
At the remote Kiyuk Lake area of southern
Nunavut, Canada, CSA Global personnel have been working with Prosperity
Goldfields Corp and a predecessor company, Smash Minerals Corp, since
2010 to complement their staff geologists and other consultants by
providing technical expertise in mineral exploration, geochemistry,
geophysics and glacial geology. Most recently, this partnership
resulted in a highly successful 30 day exploration program at Kiyuk Lake
during the summer of 2012.
Diamond drilling on the
Kiyuk Lake property in 2011 and 2012 by Prosperity confirmed the
presence of significant gold mineralisation in multiple areas along a 6
km-long trend. Gold is associated with pyrite and pyrrhotite in areas of
intense sodic alteration and has some similarities to iron oxide
copper-gold (IOCG) deposits. Continuing exploration on the property is
hampered by the general absence of exposed bedrock and an extensive but
thin veneer of glacial till. One objective of the 2012 summer program
was regional sampling of this till on a 1km2 grid in order to test for
glacial dispersal trails from previously unrecognised bedrock gold
mineralisation.
All rock, till and soil samples
collected on the Kiyuk Lake property were shipped to accredited
geochemical laboratories for preparation and analysis. It can take weeks
before the results are available, which was too long for a 30-day
programme at Kiyuk, so field portable X-Ray Fluorescence (FPXRF) was
used to analyse the till samples in the field before they were
dispatched to the lab. The levels of gold in till and soil samples are
generally too low to be detected by the method, but previous
multielement analytical work indicated that gold was associated with a
suite of pathfinder elements such as As, Sb, Co, W and Mo at levels
that could be detected using FPXRF. Till samples were dried in a heated
shed and analysed directly in the sample bags using an Innov-X Systems
Delta attached to a test stand before being dispatched to AcmeLabs for
analysis. The gridded percentile images for arsenic by the two methods
are virtually identical. Such consistency allows decisions to be made
about follow-up work in the field within days of collecting the samples,
which is critical in areas with short summer field seasons. Some of the
targets generated during the 2012 summer field program are being tested
by diamond drilling this winter.
Developed in
Denmark by SkyTEM Surveys ApS, SkyTEM is a unique and powerful
timedomain electromagnetic technology (TDEM) employed globally to
explore for natural resources The developers states that SkyTEM “is a
notable advancement in airborne exploration technology and is recognised
as a superior mapping tool for mineral deposits such as gold, nickel,
uranium and coal and for energy resources such as geothermal and shale
gas.”
A SkyTEM survey, similar to this one in Colorado, was used by Graphite One Resources in Alaska
SkyTEM
is engineered to discriminate between weak geological contrasts and
collects and delivers accurate finely detailed maps of the earth from
the very near surface to depths of hundreds of metres. In order to
achieve this SkyTEM is the only system capable of operating in dual
transmitter modes: Low Moment (LM) mode with low current, high base
frequency and fast turn off provides early-time data and high spatial
sampling for shallow imaging; and High Moment (HM) mode with high
current and low base frequency provides high quality late-time data for
deep imaging. Depending on the exploration objective the system can
operate with dual moments or a single moment based solely on HM to
maximise the depth of penetration.
SkyTEM’s
technology recently mapped conductors for Graphite One Resources that
has led to the discovery of a world class high grade graphite deposit in
Alaska. The data has a strong correlation with the bore holes and depth
extent of the deposits. Graphite One Resources’ Graphite Creek property
comprises 129 claims totalling 6,799 ha on the Seward Peninsula.
Mineralisation on the property is characterized by coarse crystalline
(large-flake) graphite within graphite-bearing schist. The
mineralisation is exposed at surface on the north flank of the Kigluaik
Mountains. It is continuous over 5 km of strike length with an
approximate thickness of 100 m and is exposed over dip lengths of 100 to
200 m. During 2012, two SkyTEM304 dual moment time domain
electromagnetic (TDEM) surveys were flown over the Graphite Creek
property. The area was surveyed with a 155º/335º line direction in order
to map possible extensions of the known mineralized trend. The planned
line spacing was 50 m and the transmitter loop terrain clearance was 30 m
in order to provide the maximum amount of detail.
The
SkyTEM data is delivered as a resistivity model generated from a series
of 1D inversions. The hot colours in the 25 m resistivity depth slice
indicate the spatial distribution of less resistive (more conductive)
material within the survey area. The northern trend suggested a
significant increase in the size of the previously known mineralised
zone. Based on this information, Graphite One carried out a sampling and
mapping programme to determine the size of the mineralised zone. The
results of the sampling program confirmed the presence of graphite along
the trend of conductors mapped by the SkyTEM304 survey. This has made
it possible for Graphite One to increase the length of the known
mineralised trend from 5 km to 18 km. A drill program was also carried
out to determine the depth extent of the mineralization exposed at
surface.
As a result of their 2012 exploration
program Graphite One has verified that the 18 km long conductor detected
by the SkyTEM304 system is directly related to wide scale, high grade,
graphite mineralisation. It has been confirmed by drilling that width
and depth of mineralisation are in excess of 250 m.
The
data presented was collected by the SkyTEM304. SkyTEM also offers the
SkyTEM508 – its most powerful system yet. The SkyTEM508 is focused on
mineral mapping and has an increased transmitter moment of approximately
500,000 NIA with eight turns on a 500 m2 loop. System development is
based on extensive experience with earlier SkyTEM systems and possesses
the same features with regard to calibrated accuracy, repeatability,
noise suppression and comprehensive, continuous monitoring of system
parameters.
A GeoProbe 8040DT rig being used by GeoTek
From exploration to mine development, from environmental monitoring to restoration and reclamation, Geoprobe Systems offers
soil, water, and rock sampling equipment, based on high quality,
hydraulically-powered, direct push machines that use both static force
and percussion to advance sampling and logging tools into the
subsurface. Geoprobe rigs
such as the 8040DT have the power to compete with larger rigs, but
their size and light weight allow for access to remote or confined
sites. Geoprobe rigs are also fuel efficient and low maintenance.
Ernco
Environmental Drilling and Coring in Sylvan Lake, Alberta, Canada,
completed soil sampling and monitoring well installations at a site
north of Waterton Lakes National Park in southwestern Alberta. Because
of the direct push and rotary functions of the 8040DT combo rig, Ernco
was able to advance to desired depths in rocky soil conditions,
primarily large cobble and sand and gravel materials that would have
presented major challenges for conventional rotary drilling equipment.
Ernco drilled ten boreholes to approximately 24.4 m. Using the direct
push feature of the 8040DT, they pushed the rods to 9 m, then advanced
the remaining distance using air rotary drilling technology and 2.25 in
drill rods. Monitoring wells were installed using 2 in and 1.5 in
prepacked screens. Another Geoprobe 8040DT, owned by GeoTek Alaska in
Anchorage, has been used at an old strip coal mine. During the mine
operations over 40 years ago, the waste had been thrown over a ledge,
creating giant spoil heaps. Since the tailings weren’t compressed down
when they were dumped, it created an oxygen-rich atmosphere that had a
lot of heat. There are still fires burning within the spoil. GeoTek
took in the 8040DT and turned carried out a 4.25 in Hollow Stem Auger
(HSA) drilling programme, taking temperature and CO readings of the
cuttings that came up. They drilled to over 45 m below ground surface,
and determined that the fires were near the 31 m. mark. It was a
challenge as the augers had to be handled with welding gloves as they
reached over 200°.
In 2012, the US Department of
Energy provided funding to install Geotech’s fixed wing ZTEM system onto
one of Bell Geospace’s BT-67’s, thereby allowing FTG and ZTEM to be
acquired simultaneously. Although this combination will initially be
applied for geothermal exploration, simultaneously acquiring ZTEM, FTG,
and magnetic data should provide a powerful structural mapping tool.
Bell Geospace continues to develop data processing and interpretation
methods that take advantage of the full gravity tensor. By using the
horizontal tensor components as well as the vertical components to grid
the data, geologic structure between survey lines higher resolution
images of the density structure. Bell Geospace has also developed a
special filter that uses the horizontal tensor components to emphasize
the strike direction of geologic features.
In recent
projects completed by 0Bell, an airborne full tensor gravity gradiometry
survey was flown over the 600 m2 Maquine Rocinha property located in
Quadrilatelo Ferrifero (QF), Minas Gerais, Brazil to explore for iron
oxide deposits. Iron oxide ore bodies occur as discontinuous lenses of
varied sizes and shapes within the banded iron formation. Iron ores in
QF can be classified into two main types, the high-grade hard haematite,
and intermediate grade ore itabiritic ore. Intermediate-grade
itabiritic ore is thought to have been formed by residual concentration
of the iron oxides after leaching of the surrounding minerals during the
Cenozoic Era. The genesis of the hard highgrade is more complex and not
well understood. This ore type generally preserves the original
banding of the hosted itabirite formation and shows high-grade
(haematite) re-crystallisation.
The measured gradient
data has been processed and terrain corrected using a background
density of 2.6 g/cc prior to evaluation and interpretation, while
an enhancement technique combined tensor components into rotational
invariants (R-1) and (R-2) that remain unchanged as the data are rotated
about the Z-axis. The measured vertical gradient (Tzz) clearly outlined
the Caue Formation which forms part of the southern tip of the regional
Gandarela fold and the first vertical derivative of the R 2 further
enhanced shallow ore bodies providing good drill targets.
Bell
comments: “The interpretation of high resolution airborne gravity
gradient combined with geological data provides new insights into the
knowledge of the lithologies and structure for the Maquine Rocinha
property; the understanding of the property’s regional and local
geologic setting; possible new iron ore deposits; and the volume of new
ore deposits, thereby giving an estimate of the overall value of the
discoveries.
Underground mine RC exploration
Cubex
has been active in RC drilling solutions for over 15 years, such as at
Elko, Nevada, where Barrick uses 12 Cubex Aries and 5200 rigs purely
employing this technology for definition drilling in narrow gold reef
structures. The company drills 150m in advance of the next main stope to
get a better idea of the ore characteristics ahead of development.
Cubex works with contractor, Connors Drilling, on providing this
solution. There is global potential for expansion of the method. In the
Australian gold industry, there is a tendency to use core instead of RC
in similar situations, however, this only offers a third the speed of
RC but is three times the cost. RC setup is also quicker. Cubex argues
that in a basic decision making application, RC offers a better
alternative to coring in contact definition work, with current RC
offering sample origin accuracy and interpretation that is on a par with
coring. The advantage is that with the Cubex rig, it can be used for
both mine production and this RC work, making it a highly cost effective
and efficient option. The mine drills 4.5 in and 4.75 in bit holes and
uses a Centre Return RC hammer, which has produced significant sample
recovery improvement over an ITH hammer with cross-over sub. The current
average drilled is about around 1,200 m per month. An RC drilling
programme is always completed ahead of production and a riffle splitter
set up on the rig is used for its simplicity.
Cubex
states: “Based on the RC drilling application being a percussive
drilling process and core drilling which is grinding of the rock
process, the RC drilling application is much faster and cheaper than
core drilling. The RC method of drilling will provide drill cuttings
from the face of the bit to be blown through a centre tube in the drill
pipe, reducing contamination, back up to the drill top drive, where the
chips are collected and marked by their location, and can be sampled for
rock type, ore grade, and other characteristics. We are currently
drilling RC holes in Nevada and which are greater than 100 m in length.”
The
main benefits that can be gained by using RC drilling include increased
definition of economic metals in the block allowing for increased
mining selectivity and optimal blending; and increased definition of the
deleterious elements in the block allowing for increased mining
selectivity and optimal blending. It can also be used to explore near
stopes and between blocks to increase definition of ore characteristics
to better guide short range planning and scheduling.
The
method also offers increased sample analysis frequency and more easily
handled samples, with samples split at the drill site and sent to the
lab after each shift. The RC method also has the ability to sample very
blocky ground, and as stated, the RC drill and crews could also be used
for production drilling during non sampling periods. Cubex adds: “The
RC drilling application is not there to take away core drills, but
rather provide the underground geological engineering team with further
information on grade control and ore contacts which will provide further
drilling data quickly and more inexpensively when compared to
conventional core drilling.”
All terrain vehicles
L’Équipe
Fabconcept, having begun mass production, is now in the marketing phase
for its new amphibious all-terrain vehicle, the KASKOO-X04. The
KASKOO-X04, completely designed in Saguenay, Quebec, has involved over
10 years of development, trials, prototypes and adjustments. The
prototype and production model have been tested over a variety of
difficult, if not impracticable, conditions and environments, in
collaboration with IOS Service Geoscientifique Inc, one of the largest
mineral exploration firms in Quebec and owner of the first production
model. The President-General Manager of IOS Service, Rejean Girard,
stated that the KASKOO-X04 can replace, in certain situations, the
costly implication of helicopters used for the multitude of tasks
related to their mineral exploration activities. Girard explains that
this invention will be extremely practical during winter, when the
access roads are closed: “There are also the vast marshy regions in
Northern Abitibi and Baie-James, as well as forest roads where erosion
over time has made them often inaccessible to standard vehicles. The
machine is used for interventions covering a radius of over 20 km
surrounding the mining and forestry camps.”
The
product’s technology is integrated on all levels – it reaches up to 40
km/h, with high quality suspension and passenger compartment offering
ease of driving and floatability. The machine is entirely manufactured
and assembled in the Saguenay plant. Only the tracks (Soucy
International), the engine (Peugeot) and certain hydraulic elements come
from external suppliers.
Geophysics instrumentation
Since
1923, ABEM Instrument has been pioneering the development of
geophysical solutions. As a complement to its Resistivity, Seismic and
Vibration instrumentation ranges, ABEM has introduced a new solution
within the time domain EM technique: the ABEM WalkTEM. WalkTEM is a
land-based Transient EM measuring system developed in partnership with
Aarhus University and founded on SkyTEM technology. It is designed for
near-surface geological surveys. The transient electromagnetic (TEM or
time domain electromagnetic TDEM) method is described as very effective
in determining electrical conductivity of the subsurface at depths from a
few metres down to several hundred metres. Since electrical
conductivity of soil correlates strongly with soil properties, TEM is a
powerful tool for mapping of conductive layers and is commonly used for
mapping sand and gravel aquifers, clay layers restricting groundwater
flow, conductive leachate in groundwater, saltwater intrusion, and depth
to bedrock.
The TEM method has been used for mining
exploration for several decades but more recently has undergone a
renaissance. Improved electronics and signal processing now allow for
acquisition of high quality data for the interpretation and
determination of a sedimentary geology.
ABEM, in
partnership with Aarhus University, believes it has made a significant
contribution to the advancement of the TEM technology resulting in
solutions capable of accurately resolving subtle changes in geology in
fine detail with excellent penetration of depth. A combined
resistivity-IP (induced polarisation) survey was carried out using an
ABEM Terrameter LS for gold exploration. The field survey was done using
an 800 m long ABEM Lund Imaging cable spread and measurements were
carried out along three more or less parallel lines. The data were
inverted using Res2Dinv, resulting in model sections with maximum depth
of the models around 150 m. The good data quality resulted in mean
residuals as low as 1-2% for both resistivity and IP models. The IP
models revealed a number of high chargeability zones, with one of the
zones at a shallow depth and thus an easy target for exploration
drilling. Adding more investigation lines would make it possible to
create 3D models of the expected geometry of the mineralisation which
would be a very valuable asset when planning a core drilling program to
delineate the 3D extension of the mineralisation.
The big picture
The
number and quality of new large-scale mineral finds is declining, and
particularly of those that occur at surface. New tools are required that
will identify subsurface deposits in mineral belts and offer a
predictive model for their discovery. The industry has advanced tools in
the form of geophysics and deep drilling technology but the challenge
is often where best to apply them.
Neftex, a UK-based
resource company has developed an integrated Earth Model that spans the
Phanerozoic and late Precambrian, primarily in support of oil industry
activity, but more recently applied to mineral exploration. The model
provides the ability to delineate and track volcanic arc activity,
subducting margins, major collisional events, large igneous intrusive
events and the Phanerozoic redistribution of mineralrich Archean
terranes through time. To date over 3,500 deposits (porphyry
copper/gold, epithermal and orogenic gold and volcanogenic massive
sulphides) are incorporated within the Earth Model with data confirming
geographic location, age of ore and host rock formation, incorporated
commodities, ore hosting minerals and host rock type.
The
validation of a model relies on its ability to identify known
mineralisation and to predict new targets. The Neftex Earth Model is
dynamic, that is, the geology at any one location will change over time
with the movement of the Earths tectonic plates. For example, if all
Phanerozoic volcanic arcs are mapped to their present-day locations then
some of them (from different geological time periods) will overlap in
areas where subduction was prolonged, or where subduction settings
affected the same area of continental crust repeatedly through
geological time. Such areas are likely to have been prone to significant
enrichment and fluid flow enhancing the potential for large-scale
mineral deposits. The group states: “Using the Neftex Earth Model to map
out volcanic arcs shows remarkable agreement with some 85% of the known
Phanerozoic porphyry copper, epithermal gold and volcanogenic massive
sulphide deposits worldwide, thereby providing a predictive framework
and global road map for future exploration.”
Back to basics
The SRK Geology Team has developed advanced geological mapping capabilities using GPS enabled tablet PCs
Bert
De Waele, Principal Consultant (Geology) at SRK believes that
geological and structural mapping continues to be a largely undervalued
tool in the mineral exploration industry. He comments: “This lack of
interest in mapping in part reflects the fact that market appetite is
focused on vague declarations of ‘mineralised corridors’ and
‘prospective structures.’ And the fast pace at which exploration
projects operate allows little time for mapping, which is perceived to
be slow work. As a consequence, mapping skills are dying out, and many
younger geologists lack the mapping skills needed to make sensible
interpretations.”
SRK believes that geological and
structural mapping should be conducted early in any project, to form a
solid basis for a cost effective exploration campaign. The cost of
initial geological mapping fades into insignificance when compared with
drilling or regional geochemical or geophysical surveys. What’s more,
the understanding gained by geological mapping allows a better
definition of meaningful and cost-effective drill hole planning,
defining target areas for geochemical or geophysical work and
establishing a testable geological/structural model.
In
recent years, the SRK Geology Team has developed advanced mapping
capabilities using GPS-enabled tablet PCs and mapping protocols that
allow the digital capture of mapping data in the field, producing maps
more quickly than ever before. A geological map in digital form and all
attached databases are usually finalised within a week of finishing
field work. The mapping data is integrated into a 3D environment
(LeapFrog) to assist in cross section generation and drill planning, and
is presented to the client in GIS and LeapFrog format. SRK also works
with a set of reputable laboratories to allow for quick sample returns
for petrographic, chemical and even geochronological analyses, which may
assist in geological interpretations.
Recent mapping
work conducted by SRK Perth include iron, base metal and gold projects
in Australia, West Africa, Southeast Asia and North America. The mapping
has ranged from regional (1:50,000) to prospect scale (1:5,000)
projects, sometimes incorporating 3D drilling data to aid
interpretations.
SRK mapping has also assisted
clients to identify target areas, by recognising outcropping
mineralisation, or structural interpretations, and where data are
sufficient, has provided a testable geological model, in some cases,
with exploration target sizes. Often, SRK is able to incorporate the
surface mapping data into 3D geological models once drill data become
available. This in turn leads to better constrained geological domains,
and a more reliable resource estimate further down the line.
New GIS modelling capability
Geosoft
saw strong demand last year for its cloud-powered VOXI Earth Modelling
technology, which has reduced the time and effort required to generate
3D models using geophysical inversion techniques. The 2012 release of
VOXI included the Geosoft Magnetisation Vector Inversion (MVI) modelling
technique. MVI allows the magnetisation direction to vary within the
model and thus take into account the combined effects of remanence,
demagnetization, anisotropy and induced magnetisation. The result is a
more realistic representation of rock magnetisation, which is the
fundamental rock property measured with the magnetic method.
New Geosoft wireframing tools for creating 3D surfaces from 2D interpretations
The
next release of VOXI will support gravity gradiometry data, including
full tensor systems and vertical gravity gradiometry. Geosoft will also
introduce Iterative Reweighting Inversion (IRI), a powerful technique
that can be used to sharpen smooth inversion results. IRI not only
sharpens the inversion result but it also improves the geometry of the
result and the amplitudes of the recovered physical properties.
In
2012, Geosoft also expanded its 3D gridding methods to include Inverse
Distance Weighting (IDW) and direct gridding. These new methods better
support the 3D gridding of a broad range of data types. Angled clipping
of objects in 3D views provides the ability to clip parallel or
perpendicular to dataset orientation or geological strike.
Finally,
a new geological modelling workflow is being developed that will
provide the ability to create 3D wireframe or geological models from 2D
interpretations. Improved 2D digitisation tools and workflow will make
it easier to manage interpretation files, share and collaborate on
models. Geosoft is adding the wireframing tools to Oasis montaj, Target
and Esri extensions. Fully integrated within the Geosoft and Esri
platform, the 3D Geosurface files can be shared with other users and
brought into VOXI to constrain inversions.
Remote site fuel
SEI
Industries’ Bulk Aviation Transportation Tank (BATT) has been adopted
by numerous bulk fuel air carriers who supply Canada’s remote mineral
exploration and mining sites, with some making its use a requirement in
their fuel delivery contracts. Users include Buffalo Airways, Nakina
Air, Alkan Air, West Caribou Air, Thunderbird Air and Nolinor Aviation,
with the BATT is being operated in a variety of aircraft from Caravan
Shorts to Boeing 737 jets.
As covered before in IM,
initially developed as a tool for South American law enforcement drug
interdiction operations, the BATT is the world’s first collapsible fuel
tank, specifically engineered to each aircraft’s interior. Instead of
rigid fuel drums that can leak and damage aircraft interiors, the BATT
is soft-sided and customised to fill the fuselage area correctly. In
addition to the hazards of using drums, fuel delivery is also more
costly because the carrier has to return with no paying cargo, just
empty drums. Once the fuel from the BATT is unloaded, the air carrier
can easily roll the tank up, store it and re-use the same floor space on
the return flight for other paying cargo such as drill core samples –
essentially cutting the cost of bulk fuel delivery by 50%.
New
for 2013, SEI Industries has also launched an extensive selection of
off-the-shelf pumps for aviation/vehicle refuelling and fuel transfer.
Built to withstand harsh conditions, these pumps are designed for diesel
or jet fuel with pumping capacity ranging from 30 GPM to 150 GPM,
depending on the pump selected. By stocking these critical pumps ahead
of time, SEI can ensure a ready-to-ship inventory for mining companies.
SEI also offers collapsible fuel storage tanks – the Arctic King, Desert
King and Jungle King – made from proprietary fabrics that offer longer
service life and operational features. IM
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