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crocoite
Joined: 06 Feb 2009
Posts: 489
Location: Ballarat, Victoria
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Posted: Aug 25, 2018 06:46 Post subject: Re: Malbunka Copper Mine, Home of the Azurite Suns - (23) |
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The previous theory that we may have been driving on azurite enrichment down the Adit has been discounted and other stories are needed to try and explain the azurite distribution where the richest areas are topographically high and at the contact with the hanging wall. The best we can think of currently is that fluids under pressure coming from below move to the highest point of their containment. In this story the structurally disrupted down dipping anticlinal cusp we had been following is the source pathway for the fluids evidenced by their active removal of first generation azurite in L0 and L1.
Ground stability in the DDD drive area is good with few problem areas in the hanging wall. Mining in the DDD during Trip 5 started with defining and cutting of a new rock pillar in preference to using timber in the small 8 metre wide ball room created there in 2016. Over the last 2 years the DDD has acted as a sump for mine water inflows during severe storms in the area. A frog was found in the sump this year but disappeared during the season. What an incredible journey that frog had made into the mine.
The Adit drive face will now become the new sump and a small dam has been raised to convey water away from the DDD. Which brings us back to weather. Ten raindrops were noted during the whole 2 months at the mine. Rain was predicted but never came. This had an effect of feral animal distributions but did not bother the normal range of bird species that are noted in the area each year and recorded in our Mine Management Plan revisions.
Locality: | Malbunka copper Mine, Western Aranda, Ltalaltuma, Australia | |
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Photo 6. L2 in the Adit face consisted of numerous coalesced suns and Adam suggested they would make exotic coffee table displays. So we are giving that market option a go in 2018. |
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_________________ Regards
Steve
Mineral Collector and Artist |
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crocoite
Joined: 06 Feb 2009
Posts: 489
Location: Ballarat, Victoria
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Posted: Aug 25, 2018 06:48 Post subject: Re: Malbunka Copper Mine, Home of the Azurite Suns - (23) |
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The more I look at the quarry face, the more complex the structures in the sediments become. What looks like simple sedimentary layers are not what they seem. The main structural deformations that occurred in the Amadeus Basin are said to have taken place during the Alice Springs Orogeny. Mylonites are a common geological feature of the region and are recorded locally in the above photo (mylonite is a rock produced by grinding of rock on rock as one slab is forced or twisted over the lower layer.). Slickensides on rocks exposed in creeks are common. The most massive demonstration of earth movements in the region is the scenic 400 kilometre fault scarp created by thrusting of the Heavy Tree quartzite over older Arunta complex metamorphics. Some basin authors advise that salt withdrawal accompanied by salt diapirism commensurate with our model of copper carbonate mineralisation were structurally important well before the Alice Springs Orogeny was underway.
Locality: | Malbunka copper Mine, Western Aranda, Ltalaltuma, Australia | |
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Photo 7. Complex faulting in the quarry face showing 3 layers of sandstone thrust over each other separated by three mylonite horizons and cut off by a regional transverse fault with down-throw in the left of photo. Near vertical normal faulting is evident in vicinity of the blue tarp. |
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Steve
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crocoite
Joined: 06 Feb 2009
Posts: 489
Location: Ballarat, Victoria
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Posted: Aug 25, 2018 06:49 Post subject: Re: Malbunka Copper Mine, Home of the Azurite Suns - (23) |
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Field work at the mine has established that local thrusting took part before and after azurite mineralisation as observed in the underground workings. The 2017 paper on the deposit suggested the copper carbonate was of lower Cambrian age. This begs the question of why is there any azurite left at all? Should it have not been altered to malachite? Is the deposit young? Still unanswered questions. That’s all in the Dreaming of the Traditional Aboriginal Owners. The TAOs pictured below asked me do I ever get bored by the mining. I replied “yes” during waste rock removal and undercutting, but advised the excitement of uncovering wonderful azurite specimens was definitely not boring.
Locality: | Malbunka copper Mine, Western Aranda, Ltalaltuma, Australia | |
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Photo 8. Traditional Aboriginal group on mine inspection visit on first week of project commencing in 2018. |
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Locality: | Malbunka copper Mine, Western Aranda, Ltalaltuma, Australia | |
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Photo 9. Last of the wood in the mine, cut by Cameron and Tracy Griffins in 2017. We now use this remaining wood as a wet weather emergency supply. |
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Steve
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crocoite
Joined: 06 Feb 2009
Posts: 489
Location: Ballarat, Victoria
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Posted: Aug 25, 2018 06:50 Post subject: Re: Malbunka Copper Mine, Home of the Azurite Suns - (23) |
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The paper published in January 2017 in Ore Geology Review (82 (2017) 170-180) titled “Primary diagenetic copper carbonate at the Malbunka copper deposit, Amadeus Basin, Northern Territory, Australia by authors Erik Melchiorre, Dehne McLaughlin, Ralph Bottrill and Jay Hight, received positive feedback from Geologists at our display room in Tucson in January-February this year. Petroleum geologists remarked on the fluid flow features in photographs of the sediments and advised the hydraulic fracturing photos showed fracture patterns similar to those achieved by artificial fracturing in petroleum wells. The difference in hydraulic fracturing in our mine compared to artificial fracture stimulation is that the mine elated fluids have come from below: artificial fracturing is introduced from above.
Researchers in copper oxide deposits were excited by the thesis that the MCM is a primary copper carbonate deposit. Theodore Bornhorst from the A. E. Seaman Mineral Museum of Michigan Tech provided a published article of a primary chalcocite deposit in Michagan State which he advised was probably the sulphur rich equivalent of our sulphur poor deposit. The low sulphur character of the primary cupriferous fluids at the MCM project was further confirmed during the year by analysis run by Dr Aleksandr Stepanov (Sasha from the 2017 mining trip) that confirmed large amounts of said chalcocite in the mine hill, as advised by past geologists who had worked there, were malachite and dark clay.
Locality: | Malbunka copper Mine, Western Aranda, Ltalaltuma, Australia | |
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Photo 10. The blues and greens of azurite in a hot fire when 2 degrees at the mine. |
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Steve
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crocoite
Joined: 06 Feb 2009
Posts: 489
Location: Ballarat, Victoria
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Posted: Aug 25, 2018 06:52 Post subject: Re: Malbunka Copper Mine, Home of the Azurite Suns - (23) |
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Despite our best assessments of specimen potential at the mine, we can not be sure what surprises in specimen type or reserve quantity may turn up in 2019. Contact Dehne on 0402450905 or dehne(.)mclaughlin@bigpond(.)com if you want to be a part of that adventure.
Cheers
Dehne and Maureen McLaughlin July 2018.
Locality: | Malbunka copper Mine, Western Aranda, Ltalaltuma, Australia | |
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Photo 11. Daniel Scott at mine work face Adit Drive dropping specimen bearing material onto seat cushions. Photo: Bob Callum. |
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Steve
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KimBerley
Joined: 07 Mar 2019
Posts: 1
Location: Rajasthan
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Posted: Mar 07, 2019 05:54 Post subject: Re: Malbunka Copper Mine, Home of the Azurite Suns - (23) |
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I like so much to know about azurite because I am researching on this rough. And your article has given me a great source to get to each and every distinct source of azurite mining. I had been to another source which gets me all the information about azurite .These two blogs are more than enough I think to complete your knowledge about azurite.
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