Post by Zoinkers on Dec 1, 2006 0:22:23 GMT -5
2006-11-29 16:32 ET - Street Wire
by Will Purcell
Shore Gold Inc. expects to mine a big bulk sample from Orion North next
year. The site of the test will depend on the results of the mini-bulk
sampling efforts now under way, but the company is already setting
aside cash. Shore will use the money to sink a shaft and commence
extracting kimberlite from a rich part of the complex, which is about
eight kilometres northwest of the Star pipe.
The plan
Shore's vice-president of exploration, Pieter du Plessis, said the
results from the first series of big holes the company is now drilling
into Orion North would be available as early as February. Similar tests
from at least three other regions within the mammoth complex would
follow. Getting those results is top priority, Mr. du Plessis said,
because they will provide the justification for sinking a shaft.
Shore thinks it will take about a year to burrow deep into Orion North,
based on its experience at Star. The vertical tunnel will penetrate
about 100 metres of overburden, much of it loose material, before
hitting the top of the kimberlite. Getting through the overburden layer
will require the same patient work and technology the company
successfully used at Star.
The main kimberlite sample will not come out of the ground until the
summer of 2008, but Shore will have diamondiferous rock to process once
it hits the kimberlite zone. As a result, the first sets of diamond
counts could come late next year or early in 2008.
Those first batches of kimberlite will likely have a lower diamond
content than the eventual target zone, but not to the same extent as
Shore experienced at Star. Shore penetrated about fifty metres of
low-grade late Joli Fou kimberlite and another forty metres of
transitional material at Star, before it hit the richer early Joli Fou
kimberlite.
Orion North experienced greater erosion than Star, and that carried
away nearly all the late Joli Fou rock. At Star, that material yielded
grades barely one-10th what the richer material delivered. The
transitional rock fared better, with grades about half of the early
Joli Fou kimberlite.
The encouragement
Shore thinks the same rock types present in Star also occur in Orion
North, but that says little about their diamond potential. Despite a
series of modest results from small mini-bulk tests in the past, Shore
thinks the huge complex has the potential to match or surpass Star's
grades.
The company bases that hope on the microdiamond recoveries and mineral
geochemistry, and the current mini-bulk program will provide adequate
details about grade variations across the key parts of the complex.
Still, Shore will need a parcel of several thousand carats to prove
Orion North has the rock value needed to support a big mine.
When Shore first touted its Star plan, the goal was 3,000 carats. The
company handily topped that target with its first test, then
immediately started a second bulk sample. The company's full Star tally
could top 10,000 carats, once a third bulk sample and a large diameter
drill program currently under way are complete.
Shore will probably try a 25,000-tonne test of Orion North, as it did
at Star. A 3,000-carat target would need a grade of 0.12 carat per
tonne, which is significantly higher than the grades found in the
earlier tests of the individual Orion North pipes. There is little
point in collecting a substantially larger sample to hit the carat
goal, as a markedly lower grade would likely prove uneconomic.
De Beers cautiously modelled a grade of 0.07 carat per tonne for a
high-grade zone within Orion North based on its earlier effort, which
probably is too low to support a mine. Still, Shore thinks that its
detailed core drilling program and the current mini-bulk tests will
allow it to outline better regions that the earlier programs missed.
Even if Shore does deliver grades comparable with Star, it will need to
produce diamond appraisals in line with the hefty values obtained from
its main project. The modelled diamond value for the Star diamonds is
about $130 (U.S.) per carat, supported by a particularly coarse size
distribution curve. Encouraging early signs from some of the Orion
North pipes suggest Shore may find large diamonds there as well.
fbruhm.proboards3.com/index.cgi?board=nf&action=post
groups.google.com/group/Global-Mining-News/msg/65bc216a866b558a
by Will Purcell
Shore Gold Inc. expects to mine a big bulk sample from Orion North next
year. The site of the test will depend on the results of the mini-bulk
sampling efforts now under way, but the company is already setting
aside cash. Shore will use the money to sink a shaft and commence
extracting kimberlite from a rich part of the complex, which is about
eight kilometres northwest of the Star pipe.
The plan
Shore's vice-president of exploration, Pieter du Plessis, said the
results from the first series of big holes the company is now drilling
into Orion North would be available as early as February. Similar tests
from at least three other regions within the mammoth complex would
follow. Getting those results is top priority, Mr. du Plessis said,
because they will provide the justification for sinking a shaft.
Shore thinks it will take about a year to burrow deep into Orion North,
based on its experience at Star. The vertical tunnel will penetrate
about 100 metres of overburden, much of it loose material, before
hitting the top of the kimberlite. Getting through the overburden layer
will require the same patient work and technology the company
successfully used at Star.
The main kimberlite sample will not come out of the ground until the
summer of 2008, but Shore will have diamondiferous rock to process once
it hits the kimberlite zone. As a result, the first sets of diamond
counts could come late next year or early in 2008.
Those first batches of kimberlite will likely have a lower diamond
content than the eventual target zone, but not to the same extent as
Shore experienced at Star. Shore penetrated about fifty metres of
low-grade late Joli Fou kimberlite and another forty metres of
transitional material at Star, before it hit the richer early Joli Fou
kimberlite.
Orion North experienced greater erosion than Star, and that carried
away nearly all the late Joli Fou rock. At Star, that material yielded
grades barely one-10th what the richer material delivered. The
transitional rock fared better, with grades about half of the early
Joli Fou kimberlite.
The encouragement
Shore thinks the same rock types present in Star also occur in Orion
North, but that says little about their diamond potential. Despite a
series of modest results from small mini-bulk tests in the past, Shore
thinks the huge complex has the potential to match or surpass Star's
grades.
The company bases that hope on the microdiamond recoveries and mineral
geochemistry, and the current mini-bulk program will provide adequate
details about grade variations across the key parts of the complex.
Still, Shore will need a parcel of several thousand carats to prove
Orion North has the rock value needed to support a big mine.
When Shore first touted its Star plan, the goal was 3,000 carats. The
company handily topped that target with its first test, then
immediately started a second bulk sample. The company's full Star tally
could top 10,000 carats, once a third bulk sample and a large diameter
drill program currently under way are complete.
Shore will probably try a 25,000-tonne test of Orion North, as it did
at Star. A 3,000-carat target would need a grade of 0.12 carat per
tonne, which is significantly higher than the grades found in the
earlier tests of the individual Orion North pipes. There is little
point in collecting a substantially larger sample to hit the carat
goal, as a markedly lower grade would likely prove uneconomic.
De Beers cautiously modelled a grade of 0.07 carat per tonne for a
high-grade zone within Orion North based on its earlier effort, which
probably is too low to support a mine. Still, Shore thinks that its
detailed core drilling program and the current mini-bulk tests will
allow it to outline better regions that the earlier programs missed.
Even if Shore does deliver grades comparable with Star, it will need to
produce diamond appraisals in line with the hefty values obtained from
its main project. The modelled diamond value for the Star diamonds is
about $130 (U.S.) per carat, supported by a particularly coarse size
distribution curve. Encouraging early signs from some of the Orion
North pipes suggest Shore may find large diamonds there as well.
fbruhm.proboards3.com/index.cgi?board=nf&action=post
groups.google.com/group/Global-Mining-News/msg/65bc216a866b558a