May/June 2013 - The ASIA Miner

Asian Intelligence
Rate of gold discoveries declines
THE declining rate of new gold discoveries
and grades across the global market during
the last decade has accelerated in the last
4 years. Data from IntierraRMG reveals that
the 2-year period from 2003 to 2004 was
the best in the study range, with more than
400 million ounces of new gold discovered.
This includes inferred, indicated and measured
ounces with an average grade of 1.65
grams/tonne.
In contrast, 2005 and 2006 had the lowest
number, with just over 150 million new gold
ounces discovered - albeit with a similar
Gold discoveries and grades during the past 5 financial years.
grade. Discoveries then increased significantly
during 2007 to 2008 with greater than
390 million ounces. The average grade also
increased significantly to 2.65 grams/tonne -
the highest in the 10 year period.
Over the next two years, slightly more than
250 million ounces were discovered with a
declining grade of 1.25 grams/tonne. This
deterioration continued through 2011 and
2012 as the amount of new gold ounces discovered
dipped below 225 million ounces
with a reduced grade of 1.17 grams/tonne.
In the 10-year study period, Africa led the
way with new discoveries of 479 million ounces
of gold with an average grade of 2.8
grams/tonne. Next was North America, although
with significantly less new ounces of
290 million, and with a much lower grade of
1.3 grams/tonne. Europe had the third most
new discoveries with 240 million ounces but
with a higher grade than North America of 2.0
grams/tonne. South America recorded 188
million ounces, while Australasia saw 74 million
ounces of new discoveries with an average
grade of 1.4 grams/tonne.
Meantime, funds raised for mineral exploration
in the three months to December 31, 2012
reveal a welcome improvement compared with
a dismal September quarter. Moreover, financings
by exploration companies themselves
also saw growth during the same period.
As indicated in IntierraRMG’s quarterly State
of the Market Exploration Report financing for
exploration reached US$1.49 billion in the final
2012 quarter, compared with US$0.65 billion
in the September quarter. Toronto Stock Exchange
was the largest source of exploration
funds for the quarter (US$586 million) followed
by the Australian Stock Exchange (US$519
million) and the TSX Venture Exchange
(US$319 million) - all measured in terms of the
primary exchanges for each financing.
Sentosa acquires Mongolia copper-gold project
SENTOSA Mining has purchased the Darvii
Naruu Copper-Gold Project in western Mongolia’s
Gobi-Altai province. The project comprises
seven semi-contiguous licences with a
total area of 62,735.8 hectares and it has
been obtained as part of the acquisition by
Sentosa of privately owned Australian and
Mongolian companies. It is within the South
Gobi Arc which hosts Rio Tinto’s world-class
Oyu Tolgoi porphyry deposit, one of the
world’s largest copper-gold deposits.
Under the terms of the acquisition agreement
Sentosa will spend Aus$150,000 on a
work program which will involve flying an aeromagnetic
and radiometric survey. The results
of this will be analysed and Sentosa
than has the right to decide whether to proceed
with the acquisition. Should it decide to
proceed, it will issue 5.5 million fully paid ordinary
shares and a 0.5% net smelter royalty
to the vendors as consideration for a 100%
interest in all of the tenements.
Historic exploration has defined multiple
prospects at Darvii Naruu with the premier
prospect being Mushroom Reef which has
characteristics comparable with a surface alteration
footprint of a porphyry copper-gold
deposit. There are numerous occurrences of
malachite in fractures with low to high grade
gold and copper in outcropping quartz veins
as well as moderate anomalism of silver, arsenic,
antimony zinc and molybdenum in soil
and stream sediments. Maximum rock chip
values of 5.8% copper and 34.4 grams/tonne
gold have also been collected.
Porphyry systems in Mongolia vary in
size, composition and nature. In comparison
to Mushroom Reef the major mineralized
centres targeted at Oyu Tolgoi occur
coincident with regional, northerly-bearing
structures with strike lengths of about
4km. Mushroom Reef , like Oyu Tolgoi, is
predominantly hosted by Devonian-aged
mafic extrusive rocks. Enrichment of copper
and gold in soil occur along linear corridors
exceeding 3km in length.
The copper values in the soils range up to
354ppm and gold up to 126ppb. Based on
the elevated concentrations of copper and
gold in soil and the depletion of other elements
it is possible that Mushroom Reef is
prospective for a partially exposed, near-core
position of a copper-gold porphyry system.
Anomaly 13 is 8km south of Mushroom
Reef and anomalous rock chip samples are
associated with widespread ultrabasic rocks
present as either sills or possibly flows interbedded
in a series of shallow marine sediments.
Highly encouraging rock chip samples
have also been collected.
8 | ASIA Miner | May/June 2013