Wonderful discussion! Who knew how important this discussion (parts 1 and 2) would be and then to record and publish it to the world like this? My long term interest in geology now has a renewed level of excitement. This is truly an inspiring discussion. Thank you, to all those who were involved in this collaborative effort. Only fireworks could have made it more exciting . . . well, actually, the discussion did have fireworks in my brain when several of the points were discussed. Well done!
Clive - las few days just rewatched all your vids...its a year later and as layman geologist i know so much more about what i see around here in the mtn.s around me in idaho usa, your videos have taught me a ton! thanx again! any more in the worx? cheers. jd
+J Dean Thanks for your comment JD. It's good to know you're getting something out of the videos. Some paid geological work is taking priority at the present, but yes, I plan to do more films this year.
I don't like dark and wet , so how do I find space gold ? Why is all metiorites Not gold ? Titanium , platinum , non reactive heavy metals , also how hot ? I'm seeing hints of impact causing viens , what's likely to pop out with plenty of energy but a rather short duration ?
So next stage of concept development is the Electrostatic discharge involvement in sudden phase change at all flash-fractal In-form-ation substantiation levels? Geologists are exceptional Observers. Complicated and messy geophysics.
Yes, quartz grows in layers. I found a fantastic site were glass clear quartz is layered with mica in layers from millimeters to centimeters. Never seen such specimens before, they look like glass covered by silver crocodile skin.
Very nice video. I'm curious, though. What would be the pressure and temperature range of these fluids? Where can I find information on phase change of these minerals? My apologies if these are dumb questions.
In my part of the world (Victoria, SE Australia) the temperature of the fluids would have been about 300° C, maybe a bit more, and the pressure in the range 80 to 175 MPa (1MPa = 145psi). The fluids had to overcome the total weight of the overlying rock before they could force open a crack to form a vein, and precipitate quartz and gold. So if the veins were buried at about 7km you would need a pressure exceeding 175MPa. These are good questions but I’m not sure where to get info on phase changes.
Fantastic videos Clive in all aspects! What are you up to these days? I am a metallurgist in Melbourne and it would be brilliant to catch up with you over a few cleansing ales.
Thank you so much for these videos. Part 1 and 2!. Just a question, what determines the content of the fluid?. In gold veins, it's easier to see several layers of quartz but just a few of them carried gold. TY
Great question - but the reasons why some veins, or parts of veins, are rich in gold and others are not is difficult to answer. Some researchers say that the composition of the wall rock (the rock that encloses the vein) is important. For example it has been observed that quartz veins in Victoria (in SE Australia) tend to be richer when they cut across carbonaceous shale. Stephen Cox talks about that in the video (Gold Bearing Fluids with Prof Stephen Cox: Part 2) at about 9:00 minutes. I also think that that there is more chance that a vein will be rich if a lot of fluid has fed into the vein over time, like in laminated quartz veins.
You know you can learn something when the expert says we don't know. Excellent talk, presented what he does know, and backs it up with evidence. Also willing to listen to other theories. Geology is a field that has many open issues for the next generation of students to figure out.
