Redrock Hydrothermal Alteration
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- Опубліковано 23 лип 2024
- Redrock alteration is commonly associated with large Iron Oxide Copper-Gold (IOCG) deposits and sometimes with Prophyry copper-gold deposits. Mapping the distribution and intensity of the alteration can tell you a lot about how big the system is and where the ore is likely to be. These examples come from the Cloncurry area, east of Mount Isa in northern Australia.
0:00 Redrock and ore deposits
0:21 Example in Calcsilicate rocks
3:09 Example with secondary magnetite
4:27 Zoning and ore - Навчання та стиль
As a passionate amateur I keep watching these videos, they are such a great find to me. I wish I could analyse geological settings so fluently. Its great to see devoted people master their field.
Theres a diorite intrusion nearby, rejected as bulk mineable because mineralisation is restricted to narrow veins although large nuggety gold was dug by old timers. It has quartz sulphide veins with Cu/Au in high grades, much magnetite. The nearby streams are loaded with magnetic sands. Haematite also occurred actually in the veins with quartz and visible gold and pieces of this rock are also in the streams. I have large pieces of it. Id hate to see the area mined in bulk anyhow because the adjacent dry scrubs with hundreds of giant figs and other impressive trees, they are worth more than the minerals imo and cannot be replaced. However it'd be great to see small scale miners reopen on the field (itself in a grassy eucalypt woodland). Maybe its too hard to comply with regs for most people. As for me I am fascinated by the complex origin of ore systems. I like solving mysteries and geology has them in abundance. This channel is a standout. Im glad you let your passion get the better of you, and put all this work on public display. For me this gets to point, in part, of what life is all about.
The decision to mine or not has many contributing factors. Geology is only one of them. Thats part of the reason that we will never run out of minerals and searching for them will always be a good profession.
@@GeologyUpSkill I certainly agree, there's little to worry about that way from where i sit. Re: environment...there are some unfortunate aspects of the environmental movement where its been used for the wrong reasons, however average people are very positive about saving natural things of value when they can understand what and where they are. Society can decide what it values and the products of mining will just fit in where they do, which i'd judge to be of forever high importance. Economic ore grades will move in whatever direction they have to. As long as people want these products and the technology they afford we will mine them on some cost basis.
Geology uni degrees are so watered down nowadays. Has anyone else noticed this? I was thinking of going back to do "Earth Science" but the major looks like it barely equips you with any knowledge to be an exploration geo. I can see myself coming out of it and not knowing 2/5ths of nothing. Even the extended "Earth Science" major has a really narrow range of courses. This is kind of disheartening for someone looking to get into exploration. Big fan of the channel Nick. You're doing a better job than the universities.
Thanks. I'm trying to cover the gaps on the practical side, but that gap is widening by the day!
Yes you are entirely correct. Geology students will never see a drill rig whilst at university but will spend their first 5 years as a rig jockey.
There is no substitute for practical hands on experience. Always remember that don’t find a new orebody in a computer in an air conditioned office.
I’m a retired career geologist (BS 1980, MS 1983) worked mostly in groundwater cleanup in Northern California. My geology education (UC Riverside) was nuts and bolts geology, which I’m really grateful for. Riverside has since deemphasized geology basics for a more “climate change” emphasis (I guess that’s where the funding is these days). What’s interesting is I have a second career as a contract field geologist working for a consulting firm in Reno, NV that specializes in groundwater issues for the big mines in Nevada and Arizona (mines it seems either have too much groundwater or not enough). This company is having a hard time hiring recent geology grads who are willing to sit on a rig with 12 hour shifts for 7 to 10-day field stints. Just finished an 8-day field stint in Central Nevada logging chips for a 1500’ boring into Paleozoic siltstones, shales, cherts and quartzites. I’ll be back out Feb 1 for another 8-day stint. What’s funny one of the drillers was referring to me as “OG”. I thought it meant “old guy” when in reality it means “original gangster”, which is a sign of respect I’m told. I’ll take it! I originally wanted to work in mineral exploration out of college. Did summer field stints for Newmont and Chevron in Montana and was all set to start a career…however a big recession hit in 1983 with gold, silver and base metals dropping like a rock (pun intended) and no one was hiring. One of the rejection letters I got at the time said the probability of me getting a job in mineral exploration was less than zero. That’s pretty low. Anyway, keep up the nice work I’m enjoying your videos a lot.
I literally understand little of what you say because I am uneducated in this field completely, but my knowledge grows daily from this passion I have felt pull me completely, my dream is to become a field geologist, I am thirty five, and have 14 years further of guiding and fathering two amazing kids before the youngest will be deemed old enough by me, for me to be able to spend long periods away from home as I'm a single father, but for the last few years since I've discovered my passion for all things from the deep and past it's been my total pleasure to be continually educated and inspires by people such as yourself. I thank you for your time and effort spent making these films for us to learn from.
Thanks very much. Comments keep me motivated to make more videos :)
Thank you for this video
Funny how rewatching -rewatching and watching new….I can understand outcrops in BC Canada…..thanks
Thats great Dyanne. Redrock alteration can be quite subtle. Best to see it first hand. Second best to watch the video a few times ;)
You're are the best ⛏️
Only in my very narrow niche and after cutting out all the bloopers!
Genius, thanks so much!
Thanks Walter. I plan a series on other types of hydrothermal alteration as I accumulate the necessary footage.
@@GeologyUpSkill A comparison and contrast of metamorphic, intrusion and porphyry gold systems alteration would be greatly appreciated. I really enjoy your videos and learn lots! Thanks...
Love the info you show, along with the variations that are possible. Have you done any video’s out in the Chillagoe area, with its amazing bluffs, abdicated faulting, and many varieties of deposits and their origins?
Thanks very much Greg. I haven't worked in the Chillagoe area for a while, but it would certainly be a great place to make some videos. Lots of interesting intrusives and hydrothermal action, not to mention skarns!
Thank you sir
Much appreciated!
Hi Nick great series of videos. Do you have anything on komatiites, Olivine pyroxenite, tremolite, serpentine, pyroxene spinifex-textured metabasalt. Thanks
Thanks Rob, there is a bit on Serpentinite gossans in one of my videos. I plan to make some more on individual minerals as good samples come to hand.
@@GeologyUpSkill Awesome cant wait to see them, will stay tuned.
Watched several of your videos thinking this looks like Mount Isa/Cloncurry region. Finally got my answer today. Be interested if you could gain access to the area of old Mary Kathleen Uranium mine and describe some of the mineralisation there.
Yes, a lot of my videos are in that region. There is just so much interesting material to work with. I haven't visited the old Mary K pit, but worked a lot to the south so I'm quite familiar with the geology!
❤❤❤
Thankyou!
Thank you for these helpful presentations. Perhaps you could answer a long-standing question for me. I found a mottled red rock in Ormiston Gorge in the N.T. last year and it looks to me like a metamorphosed sandstone with numerous white "splodges" which I suspect are hydrothermal quartz intrusions. Are you familiar with the geology of this region of Australia and is this a sufficiently detailed description to take a guess at an identification? My suppositions may be way off of course but I'd be grateful for some suggestions - the darn rock is really bugging me!
Given the location, I suspect it isn't red-rock alteration, but the only way to be sure is to look at it. You could send me some clear photos to geologyupskill@gmail.com
i have seen pink albitization in low scale IOCG, in deposits near the atacama fault system, Chile. could it be considered the low intensity analogue? Regards!
Absolutely. In unaltered igneous rocks that most people study at university, pink feldspar usually = K-Feldspar. In the world of hydrothermal alteration ANY feldspar can be pink.
So is this rock considered metamorphic due the alteration or an "altered" sedimentary rock? (not a geologist).
Metamorphic generally implies rocks that have been changed in some way by heat (but not enough to be melted). Alteration generally refers to changes that resulted from chemical reactions (usually involving some water). How you get that water into contact with the rock and where it came from is a very interesting branch of geological study!
how did you figure out they are albite veins??
Just comparison with other similar systems. Occasional crystal shapes confirm that they are feldspar, but could still be K-feldspar.
Hey Nick!!! My dad says that he knows you. He goes by the name of Baz but his actual name is Barry Jesse Cotton. He went to University in Queensland!!! Hopefully u can maybe give him a quick call if you remember him.
I only have his Lao number. Is he still using that?
No. Dad and our family decided to move back to Perth. I’d be glad to give you his number if you’d like to give him a call.
@@jamiexayvong288 OK, My contact is geologyupskill@gmail.com
Seriously, why is this not taught in my course? Kinda feel ripped off. Lmao
By the way, how do you identify the actinolite in the field?
Our industry has a big problem because we are training fewer geologists with field skills as demand for new metals rises. I'm trying to address that issue in a small way.
Actinolite has a distinctive combination of dark grey-green colour and prismatic to fibrous habit, often in radiating bunches. Large crystals sometimes show two cleavages or crystal faces at the classic 120 degree angle common to most amphiboles.
@@GeologyUpSkill Thank you