InvestorsHub Logo
icon url

ShortonCash

01/18/12 11:30 AM

#6971 RE: scubastevemd #6969

Depends if you think the subeconomic copper find is the end or just a beginning it is not obvious...in fact it could be part of the drilling program to see how much the copper or the alteration had effected the rocks at a location of the highest reading...suggest you read up some more...google sub economic copper and mafic-ultramafic and maybe you see that it is all part of the type of deposit...look at the copper percentages in the last picture of OD....


exploration of the.... mafic-ultramafic intrusives was led by major international mining companies using a layered intrusive exploration model, and resulted in the delineation of a small sub-economic ....copper resource at ......(.......0.27% Cu)

has ultimately led to a complete reinterpretation of the mineralization controls for these magmatic deposits. The......-Cu deposit has some important affinities with Voisey's Bay and consequently ........ intends to adopt this relatively new conceptual model to guide our exploration programmes, which will test the potential for zones of economic-grade......-copper:

Some of the word above have been delete above from the text below
as the discovery of sub economic copper at one location may mean that there is not a mineable copper resource at the location it may however in a mafic-ultramafic (Rusty Ridge) test for the potential of economic grade copper nearby or deeper....

http://albamineralresources.com/text/projects/arthrath.html

Exploration Model and Potential

Over thirty years ago, exploration of the Aberdeenshire mafic-ultramafic intrusives was led by major international mining companies using a layered intrusive exploration model, and resulted in the delineation of a small sub-economic nickel-copper resource at Littlemill-Auchencrieve (3Mt averaging 0.52% Ni and 0.27% Cu) and the identification of an extensive nickel-copper mineralizing system at Arthrath.

The discovery of the world-class Voisey's Bay Ni-Cu-Co deposit near Nain in Labrador, Canada in November 1994 has ultimately led to a complete reinterpretation of the mineralization controls for these magmatic deposits. The Arthrath Ni-Cu deposit has some important affinities with Voisey's Bay and consequently Alba intends to adopt this relatively new conceptual model to guide our exploration programmes, which will test the potential for zones of economic-grade nickel-copper:

deeper within the existing Arthrath mineralized system;
further east along strike where faulting may be exposing deeper levels in the Arthrath intrusive;
further west in the Arnage Haddo-House intrusive mass, particularly at the base or entry point of the Arthrath dyke.
At this stage Alba considers that the main value of the Arthrath nickel-sulphide mineralization lies in the possibility of successfully applying this new and appropriate conceptual exploration model to transform the potential of the project by identifying higher grade areas within currently known mineralized zones or new zones of previously unknown mineralization

.


What would one barren drill one mean? at OD it might mean you drilled the center of the Gravity Anomoly does one barren hole at Ken Mountian mean its not a OD type deposit NO... it does not...
does drill one hole in sub economic copper mean the copper is not there no it might mean there is good new coming from the rest of the cores or it might take additional drilling...hard to say



Does drilling 2 holes mean you are going to hit the OD deposit.. no you can see it was the 10th hole that produced results back then...now we have 2 hole BHEM which Vale is very good at...as a matter of fact some geos hire have experience in the very same cores at VB


Funny thing about assay collection they are collected to see whats on the ground and the core results release todate show the same elements in the cores...
icon url

955

01/18/12 5:56 PM

#6983 RE: scubastevemd #6969

The following excerpt from an interview with Dr. Roy Woodall will answer your question about sub-economic copper deposits:


Dr Roy Woodall
Earth scientist

Contents

Introduction
Summary of career
Extract from interview and focus questions
Activities
Keywords

You can order the DVD from us for $15 (including GST and postage).

Introduction

Dr Roy Woodall was interviewed in 2008 for the Interviews with Australian scientists series. By viewing the interviews in this series or reading the transcripts and extracts, your students can begin to appreciate Australia's contribution to the growth of scientific knowledge.

The following summary of Woodall's career sets the context for the extract chosen for these teachers’ notes. The extract discusses the persistence needed to discover the huge ore deposit at the Olympic Dam mine site. Use the focus questions that accompany the extract to promote discussion among your students.

Summary of career

Roy Woodall was born in Perth in 1930. He left school as a 16-year-old and worked as a junior clerk in the Public Works Department. He continued his studies at night at the Perth Technical College and was able to gain entrance to the University of Western Australia where he earned a BSc (hons) in geology in 1953. During his university years, he took vacation work with Western Mining Corporation (WMC) which operated goldmines at Coolgardie, Kalgoorlie and Norseman. In Norseman he was exposed to how the company applied science to its exploration work. After graduation he worked for WMC.

Woodall travelled to the USA on a Fulbright Scholarship and was awarded an MSc in 1957 from the University of California at Berkeley for studies in ore deposit research. He returned to WMC and remained with the company for his entire working life. He held a number of appointments ranging from geologist through to chief geologist (1967), exploration manager (1968) and director of exploration and board member (1978). He became a non-executive director in 1995.

Over a long career, Woodall has made extraordinary contributions to the science of mineral exploration and mine development. He and his teams have been instrumental in the discovery and development of many of Australia’s commercially important mineral deposits including Kambalda, Western Australia (nickel, 1960s), Yeelirrie, Western Australia (uranium, 1971), Olympic Dam, South Australia (copper, uranium, gold, 1975), and Ernest Henry, Queensland (gold and copper, 1991). Three of these deposits – Kambalda, Yeelirrie and Olympic Dam are ore deposits the like of which had never previously been found anywhere in the world.

The discovery at Olympic Dam, beneath 300 metres of barren rock, was among the most spectacular of his scientific achievements. The discovery revealed the fourth largest copper deposit in the world, the largest uranium deposit in the world and the largest gold deposit found in Australia. Woodall also participated in petroleum exploration with successes in South Australia and Western Australia, and by applying the latest science and engineering knowledge, helped to revitalise production from oilfields in the United States of America.

Woodall has received numerous international awards including the William Smith Medal (1983) of the Geological Society of London, the William Lawrence Saunders Gold Medal (1988) from the American Institute of Mining Engineers and the Clunies Ross National Science and Technology Award (1993). He also received an honorary Doctor of Science (DSc) from the University of Western Australia in 1985. He was made an Officer of the Order of Australia in 1981 and received the Australia Centenary Medal in 2001.

Woodall was elected a Fellow of the Australian Academy of Science in 1988 and was awarded the Academy’s Mawson Medal in 1984, the Haddon Forrester King Medal in 1993 and the Ian Wark Medal in 1996.

Back to top

Extract from interview

Persistence pays off, with uranium as a bonus

Your first drilling target seems to have presented you with something of a conundrum.

It did. Well, what to do next? We drilled some more holes. We’re now out in the desert [laugh], over a hundred kilometres from any known copper mineralisation, drilling expensive holes which cost at least $100,000 each, following up copper mineralisation of a type that neither we nor anyone else in the world had ever seen before, in a strange hematite-rich rock which we subsequently recognised as brecciated granite.

Tim and Hugh had agreed on a second target some distance away, so we drilled that. We found nothing. We came back to the location where we did get that ‘sniff’ of copper in the first hole, RD1; we drilled a second hole, and we found nothing. We drilled a third hole and found nothing. Now, I tell you: in many companies, at this stage the managing director would have phoned up and said, ‘You guys, stop wasting my money drilling holes out in the desert and finding nothing, thank you very much. It may be scientifically interesting, but I’ve got shareholders to satisfy.’ But we persisted! We drilled a fourth hole and found nothing. We drilled the fifth hole and we got a similar intersection to the first hole, a ‘sniff’. Well!

What was the length of the intersection?

Initially, 30 metres. That may have seemed a big intersection, but now you’re down 300 metres, it’s only 1% copper, and with copper only 50 cents a pound such an intersection is uneconomic.

This is where the confidence of the management – the WMC Board and the Managing Director and, especially, the Chairman – became so important. They never once questioned our desire to keep drilling. Why did we keep drilling? Well, we’d found an unusual copper mineralisation. Sure, it wasn’t economic, it was sub-ore grade. And we had drilled a lot of barren holes that didn’t find anything. But here was the most astonishingly fractured rock, a place where perhaps a great orebody might have formed, so we kept going. Hole No. 6 found nothing. No. 7 found nothing.

This is, by ordinary standards, almost perverse persistence, isn’t it?

Yes. We now know that some of those drill holes went quite close to very high-grade ore and we were just unlucky. But I am sure that many, many people and many, many companies have been in this situation looking for an orebody, having spent a lot of money, and have then walked away after drill hole No. 9! When do you stop? We kept going because of these exciting-looking rocks. Then we drilled RD10 and we intersected over 200 metres of 2% copper. And – what a bonus! – it also had a significant gold content and a significant uranium content.

Copper and gold are commonly associated; if you were getting the copper values, it was natural to look for gold. But what made you look for uranium?

That’s a good question that I’m finding hard to answer, because it was back in 1976. Why did we look for uranium? That’s a good question: why?

Of course, there is a lot of uranium mineralisation in South Australia, such as at Radium Hill, so that state would have been uranium conscious. Perhaps it was almost a standard thing, almost automatic to look for it there.

I can tell you this: it was not because we could see the uranium mineral. We now know that the uranium minerals – and there are three in the ore – are very fine-grained. Why did we put a scintillometer over the core? Well, we did! Maybe we were just much better researchers back then than we gave ourselves credit for. [laugh]

Another person that was very important to this team was our research petrologist, Geoffrey Hudson. It was Geoff who had said, ‘I’m sorry, Douglas, this is not a hematite-altered basalt or dolerite; this is a brecciated granite!’ I would suspect that it was Geoff who put the scintillometer over the core, just to check it out.

All I know is that all the Western Mining Board, including the Managing Director, wanted to visit this desert place called Olympic Dam. We subsequently had a little airstrip constructed but at this stage, in the early days, we flew in to Woomera, which had an airstrip, and then drove out to the desert to have a look at this core – very exciting stuff.

Where has the Olympic Dam mineralisation come from?

Once you had recognised that the mineralisation occurred not in a basalt but in this highly fractured granite, it was far from obvious where the copper, uranium and gold might have come from. What were the thoughts concerning the source of the ore minerals and metals?

When we saw the core from RD10, we didn’t care ‘two hoots’ where the copper came from; we didn’t even think about it. Now, though, we know that this is at least an 8 billion tonne ore deposit in which there are very large quantities of copper, sulphur, iron – about 30% to 40% iron – uranium, gold. Where does all this vast amount of metal and mineral come from? The source has to be a giant one. The ore deposit is the fourth largest copper deposit found anywhere in the world, it’s the fifth largest gold deposit found anywhere in the world and it’s the world’s largest uranium deposit, by a country mile. Nothing comes anywhere near it for size. So we have this remote part of South Australia, where cubic kilometres of granite have been fractured by some dynamic earth-force; where has this astonishing concentration of copper, gold, uranium, sulphur and iron come from? We don’t yet know the answer. It’s a great question for the next generation or two of earth scientists to worry about.

An edited transcript of the full interview can be found at
http://www.science.org.au/scientists/interviews/w/woodall.