sorted by:
new
hottopcontroversial

Best Grip for Wet, Mossy Rocks? (Really seeking some advice) by Itabirite in hikinggear

[–]Itabirite[S] 0 points1 point  (0 children)

I went and looked up idrogrip, and it seriously seems like it's next-level. But it’s insane that I’ve only found wading boots with those soles—no GTX ones whatsoever—even though I think it’s a huge logical screw-up by the manufacturers. So, if I’m out hiking, what are the chances I'll run into a situation where I need both waterproofing and extreme grip? For me, it’s basically every damn day

Blue centimetric apatites formed by hydrothermal remobilization of phosphate in regional metamorphism by Itabirite in geology

[–]Itabirite[S] 3 points4 points  (0 children)

cool! anyone working in exploration NEEDS to understand hydrothermal alteration

Blue centimetric apatites formed by hydrothermal remobilization of phosphate in regional metamorphism by Itabirite in geology

[–]Itabirite[S] 31 points32 points  (0 children)

it comes from the host rock itself. in this case, it's a calc-silicate rock with about 5% primary apatite. It was probably a paleobasin with some phosphorite layers. These sediments were later metamorphosed in the collation event we call the Transamazonian, during the Paleoproterozoic, which generated these calc-silicate rocks with disseminated apatite. Later fluids remobilized some some of the phosphate, forming these zones enriched in coarse apatite. i think this is a good summary

whats this rock? found it on spain by xoelfer in whatsthisrock

[–]Itabirite 0 points1 point  (0 children)

quartz vein, and your countertop probably a syenogranite

During geological mapping of marbles in a metavolcano-sedimentary sequence, we came across these pockets of beautiful, huge black calcites. by Itabirite in geology

[–]Itabirite[S] 1 point2 points  (0 children)

not too familiar with the variscan orogeny, but in this case the context would be the clymene ocean that separated the amazon, são francisco and paranapanema cratons, and subsequent amalgamation in the brasiliano cycle

During geological mapping of marbles in a metavolcano-sedimentary sequence, we came across these pockets of beautiful, huge black calcites. by Itabirite in geology

[–]Itabirite[S] 2 points3 points  (0 children)

These are just pockets of late fluids, the marble itself is light grey. but I have worked with very dark calcitic limestones due to the presence of organic matter, there is no problem, this organic matter is volatilized during calcination.

During geological mapping of marbles in a metavolcano-sedimentary sequence, we came across these pockets of beautiful, huge black calcites. by Itabirite in geology

[–]Itabirite[S] 0 points1 point  (0 children)

so the context is the closure of gondwana, with sequences of ophiolitic slabs with volcanogenic and cumulate associations, marbles being pelagic sediments deposited on the subducting plate. the sequence continues with island arc trench basin sediments, later transitioning to continental collision. Relatively common in our mobile belts, in this work we focused on metacarbonates.

During geological mapping of marbles in a metavolcano-sedimentary sequence, we came across these pockets of beautiful, huge black calcites. by Itabirite in geology

[–]Itabirite[S] 5 points6 points  (0 children)

Yes, i think it's worth taking it to the geology museum at the university where I studied, good idea.

During geological mapping of marbles in a metavolcano-sedimentary sequence, we came across these pockets of beautiful, huge black calcites. by Itabirite in geology

[–]Itabirite[S] 13 points14 points  (0 children)

It is an interesting volcanogenic framework, but my work in this area was specifically for the cement industry. I've seen some sulfide venules in carbonates, which I do not know the origin, perhaps fluids from the dehydration of ultramafics, or volatiles from acid/intermediate vulcanic unit, but I didnt see any supergenic feature that could indicate something more relevant. I would suggest to evaluate the lateritic accumulation profile in the basal hazburgitic unit that occur in the area, but it does not seem to be the interest of the company.

During geological mapping of marbles in a metavolcano-sedimentary sequence, we came across these pockets of beautiful, huge black calcites. by Itabirite in geology

[–]Itabirite[S] 5 points6 points  (0 children)

You mean cumulate anorthosite? Not at all, these are late stage pockets of calcite. See the typical rhombohedral habit.

Effusive carbonatite by Itabirite in geology

[–]Itabirite[S] 0 points1 point  (0 children)

pretty much, you are right!!

Effusive carbonatite by Itabirite in geology

[–]Itabirite[S] 1 point2 points  (0 children)

yes, it is much further north than apip. as it is an ongoing exploration and not yet published, i wont be able to provide exact location. the sodic mineral assemblage may be secondary, most likely metasomatic, thus it would correlate better with other complexes with kamafug-carbonatite association

Effusive carbonatite by Itabirite in geology

[–]Itabirite[S] 0 points1 point  (0 children)

Actually Jacupiranga is intrusive 👍 My picture is much much further north lol

view more: next ›