Biomineralization (Pt 2): Fe Hydroxide, Magnetite, Mn Oxides, Clays, Amorphous Silica | GEO GIRL

[@canadiangemstones7636]

Phenomenal content, much appreciated!

[@KerriEverlasting]

Does regular clay contain filamentous organic structures or any other bacteria? How do I know what kind of clay I have? There is an ancient volcano near here called Barrington Tops, NSW but also I read the fossils I find are from an ancient pleistecene sea that this land was once a seabed.

[@GEOGIRL]

Well then there are two options, it could be clay from weathered volcanic silicates or it could be clay that was laid down in a calm aquatic environment. Let's start with the basics: What color is it? Are there laminations or stratification (thin layers) in the clay bed? If there are no layers/laminations/stratification, then it may be weathered silicates. If there are laminations or strata, it was likely deposited in an aquatic environment. Another sign of aquatic deposition is if it is dark gray or black or even greenish, the darker, the more organic material present which indicates organic matter accumulation on the seafloor. If it is lighter in color and perhaps reddish, it is likely weathered volcanics (red due to the Fe). We can also look in the beds (or rock layers) above or below the clay layer. if the layers above and below were deposited in an aquatic environment, then it was likely aquatically formed clay, and vice versa for the volcanic scenario. So can you desribe for me the color, any structures/lines/layers present, and the beds above and below the clay? Thanks! (I am invested and curious now haha)

[@KerriEverlasting]

@@GEOGIRL haha can I send pictures? I'd describe it as mostly rusted orange, deep red and parts of white/grey/yellow... I mean the spectrum is the full glory of nature. We dug piping ditches and I begged them not to fill them in. But nooooo they said we need to walk on actual ground. Ugh. But I did try to rescue some and took photos. It's literally dominating my thoughts about 80% of my day. Endless questions. It's a seabed. Also a volcano low land (possibly). But when we dug dry ground water seeped into the ditch from below ground. We are on an incline and there is a valley we sort of overlook that has a creek running through it.

[@GEOGIRL]

@@KerriEverlasting Based on the red/orange/yellow colors, my guess is it's dominately iron oxide from weathered volcanic rocks. But I would absolutely love to see pics! Here's my email: [e-mail]

[@KerriEverlasting]

@@GEOGIRL sent you a bunch of pictures!!

[@GEOGIRL]

@@KerriEverlasting Great! I'll take a look at them later today ;D

[@colubrinedeucecreative]

Wow! This extended well beyond my imagination. For my favorite of these, it would have to be desert varnish. I had no idea that was the case! For the first time a couple of weeks ago, I had been noticing that when you see reds and dark browns on rocks, like on hillsides, that it is indicative of iron being in that rock as it is rusting. Turns out, it could be much more than that!

[@GEOGIRL]

Haha yes!!! I am so glad you can relate it to what you are seeing in everyday life, that's the best way to see that these processes are happening everywhere ;D

[@jjnoguera]

Muy buen video, bien sintetizado y explicado

[@GEOGIRL]

Thank you so much! I was worried this video/topic would go under appreciated, but I am so glad you liked it and took the time to comment, thank you! :)

[@alejandrorubio4424]

This is succinct and easy to follow. I was wondering "What biological processes lead to mineralization and... why?" That question returned your videos immediately and I'm nerding out and having fun learning! Thanks!

[@GEOGIRL]

This comment made my day, so few people watch or appreciate my geobiology content, but I absolutely love it! So glad I was able to answer your questions about biomineralization, thanks for the comment! :D

[@barbaradurfee645]

Interesting session Thanks!!

[@carissa8283i]

Great job on the video

[@lethargogpeterson4083]

So THAT'S how you get thumbnail pictures.

[@laramcp]

Really great content and didactic skills! I would just be interested in seeing some paper references of the findings/claims you mention, since I see some things are deeper than we can find in the textbooks :)

[@boomerphillips1596]

Fascinating video series! Does biomineralization affect or trigger development of any type of agates or precious mineral deposition?

[@GEOGIRL]

Great question! Agates form abiotically as do many precious gems, but one example I can think of that is biomineralized is pearl (aragonite). Other than pearls, it depends on what you consider precious, I guess. For example, pyrite (fools gold) can form both abiotically or biogenically. However, the biogenically formed pyrite is not necessarily as beautiful as abiotically formed pyrite because, like I mentioned microbes tend to form amorphous minerals rather than crystalline minerals, and this prevents the formation of big golden cubes like we see in crystalline pyrite. Instead biogenically formed pyrite (and any other precious minerals that are biogenically formed) will probably be small shiny flecks in dull black shale or other sedimentary rocks and won't be that concentrated or exciting to look at. But there are probably other exceptions to this rule (like pearl) that I am missing, so this is just a generality. Let me know if you can think of any others! ;)

[@siyacer]

Beautiful

[@JoesFirewoodVideos]

I’m ready to learn something Rachel, please teach me! I ❤️GEO GIRL

[@GEOGIRL]

I hope you learned a lot and enjoyed it :)

[@johnfrancis9668]

You do have a great vocabulary. I hope you take this correctly (I am 75 yrs old), you are probably not an easy person to understand on the first date. :)

[@JasonKale]

Do you ever say to your self after making a video, What did I just say...haha...Theres a lot of terminology in this one over my head but I get the gist of it..I see siliceous matrices as a future Band name for someone..haha

[@GEOGIRL]

Hahaha not right after, but I definitely say that sometimes if it's been a while since making the video lol! When I go back and watch old ones I sometimes think 'dang, I do not remember learning all that' haha! Honestly, I have to go back and watch my videos sometimes to try and refresh on things I have forgotten😅

[@katalackatt76]

But can you SHOW it happening???!!!