Well, you didn't exactly solve the question of origin, but I'll certainly forgive you for that. Fascinating stuff and I can't help but wonder if all the models didn't function at one time or another. I lean toward the sedimentary model myself, but can't make a really legitimate argument for it other than........ most BIFs certainly look sedimentary in origin!... and how does Occam's Razor work. it seems to suggest that the simplest answer is most likely the accurate one.

Ta the video. Finer fractions deliver better results all-round when reconnaissance Au prospecting such as with moss-matt samples (Canada etc..). We use fine fraction clay componens from calcrete (caliche) for areas of duricrust, but Namib and Kalahari Sands can still be difficult to get a signal through. Gypcrete is another matter. I have often observed visible Au on chlorite vein selvages to quartz-carbonate veins. Very thin foil, almost Goldene one could say. All the best from Namibia.

Ok, can you help me out here. I've only ever heard it pronounced like: poorfurry. And it sounds like you're saying poorfree. Am I wrong? Because I'd rather not sound like a dummy when I talk to my geologist friends. I'm not a geologist. I can make machines to crush rocks. But as far as what kind of rock I'm looking at, beyond, slate, granite, sandstone, limestone, and quartz. I don't know much.

I have taken a little chemistry and no geology after high school and my hobby is prospecting, so I come across a lot of banded iron and I study these beautiful and interesting rock samples. It seems like the repeated bands in banded iron are too regular to be explained by sedimentary action alone. Iron has two oxidation states Fe+2 and Fe+3, so iron oxide could be written as FeO and Fe2O3. And yet magnetite is Fe3O4, which can't be explained as a stable molecule or as an oxidation state of iron. I feel it's all a function of magnetic attraction/repulsion in the fluid state. So here is my idea, and please set me straight if my reasoning doesn't hold water: Magnetite is not a molecule; it's a magnetic conglomerate. It's a series of alternating molecules of FeO and Fe2O3 and its magnetic properties draw in additional FeO and Fe2O3 until their magnetic attraction is "satisfied" by forming a repeating sheets or layers of iron oxides at which time it repels additional iron oxide. A short distance from this layer (and as it is forming), this magnetic repulsion is weak enough for this process to be repeated, forming another iron (magnetite) conglomerate layer or band. Being molten by its location adjacent to or combined within a magma chamber, the heat permits these molecules to flow (over considerable time), thus forming the layers or bands. If my idea doesn't hold water, please let me know where I am in error. The layers are simply too regular to be explained by sedimentary action, in my opinion. Thank you.

Why not in other ages?

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Very nice 👍🏼

Well put and easy to follow

Thnx thnx for this video I am searching for this topic from month ago but i don't get any proper to the point videos. This is really very very help full to me. Thnx

I spend my summers Rockhounding near Norland, Ontario and I found this presentation very interesting and informative thank you 🙏. I filmed some of the rocks I have found there. Awesome crystals too so have a look if you like. I love it 🥰

cool,, thank you

3:01 "thinining" Just learned a new word 😅 Jk. Nice presentation. Appreciate it!

Good work, hope you do more!

Good day, it's helpful a bit. But there's no relatable scenario or examples and explanations I can read all these in Sam Broggs textbook

good show good narrative.. i used to work quarrying in the porphyry open cast pits west of herberton far north queensland australia... bolster hammer sledge hammer chisel and shovel... preindustrial revolution standards but rewarding work

I thought he spoke okay. Heard much worse.

you need to speak more clearly

Literally your helping me with my test rn good looks nice presi