One Of My Current Professors Was At The Conference Where Plate Tectonics Was Officially Accepted As A

Indigenous knowledge of palaeontology in Africa

“we only have bones as evidence so every scientist is just guessing stuff, right?” 🤨

Ohhh my gosh, thank you for your post about geologic events and tips on writing them! If you don't mind, can I ask you about cave systems? Some of the more commons types (mineral types and formations) vs some of the more spectacular/rare finds and the conditions for their formation?

Hello and thanks! Caves typically are formed out of limestone (a sedimentary rock). Limestone is a rock mostly made of calcite/ calcium carbonate that is formed in the ocean. Once the ocean level lowers or the land rises due to mountain building events, these rocks get exposed to the surface where rain (which is usually always a little bit acidic) will begin to react with the stone (Similar to your teeth and soda). Once this process begins it will make the caves we know and love.

There are a couple interesting things that can happen though! First, dissolving rocks means that the water is full of minerals, that means that while that water drips from the caves it will precipitate out those minerals creating stalactites and stalagmites on the ceilings and floors. This also means that they will be made out mostly pure calcite!

Another interesting thing is that because they were on the ocean floor, it means that there will be a lot of fossils present from an ancient ocean.

So, most times, the only things you will find in caves is calcite and fossils. However in some rare instances you can have salt caves, which are also sedimentary but would be associated with the drying of oceans (You would also be able to probably find gypsum in those caves as well).

Other rare and interesting caves could be formed from hydrothermal water (hot water generated from volcanic activities), this opens up a world of different things that *could* be present including metals being deposited in the stone (gold, silver, or copper). That said, this is just me inventing excuses for if you want it to be mineable.

Some natural disasters associated with cave systems being under the land would definitely be sinkholes! There can also be entire rivers that just disappear underground.

I truly hope this helps! If someone who knows more about caves sees this, please feel free to add comments!

i love grocery shopping!!! The best parts are when my hands go numb and my heart and lungs get to play jump rope!!!!

Shout out to yet another day of me ignoring my homework! I knew you were there the whole time! I was consumed with self inflicted brain pain and did nothing! It's hard to be alive! Thank you!

Let's look at this with a handful of dinosaurs:

Microraptor

Anchiornis

Vegavis

Titanis

Secretarybird

"Nonavi(la)an Dinosaur": Includes Microraptor. Does not include the rest.

"Non-Neornithine Dinosaur": Includes Microraptor and Anchiornis.

"Mesozoic Dinosaur": Includes Microraptor, Anchiornis, and Vegavis

"Extinct Dinosaur": Includes Microraptor, Anchiornis, Vegavis, and Titanis

"Living Dinosaur": Includes Secretarybird

"Neornithine Dinosaur": Includes Vegavis, Titanis, and Secretarybird

"Cenozoic Dinosaur": Includes Titanis and Secretarybird

"Avia(la)n Dinosaur": Includes Anchiornis, Vegavis, Titanis, Secretarybird

"Dinosaur that looks like a bird": literally all five of them

It saddens me deeply to know I cannot collect every rock

I cannot collect the smallest rocks because I would lose them

I cannot collect the biggest rocks because arm's weak

I cannot collect the funkiest rocks because no money

I cannot collect the spicy rocks because they hurt

I cannot collect the space rocks because gravity

What horribleness, how dare existance not allow me the rocks

Oh well, at least the'res plenty of rock that I Can collect

Hullo-geology student.

These looks like fluvial, or river, cobbles. They get the rounded shape from moving down-stream, the rounder the rock the longer they stayed in the river.

The top one on the right, sort of white-ish, looks like a chert pebble. This is made of the same stuff as quartz, and is super resistant to weathering, so they last a long time, especially in river systems.

Both of the middle ones look sort of like granite or perhaps a breccia. Breccia is a form of sedimentary rocks where smaller rocks get cemented together and make a bigger rock. The angular shapes of the rocks looks like feldspars, indicatinf a granite that got weathered. I think that the bottom left one is also a granite.

The top left one and bottom left one I dont really know. They both kinda look like granites, but it is difficult to tell. The bottom left one looks like it cooled with magma mixing, so there are larger grains with smaller ones, a texture called porphyritic.

I should note, this is based almost entirely on grain size, coloration, and pattern. I am also guessing because I don't know the geologic history of the area. Soooo i might be wrong but this seems like the most likely based on the images.

Thanks for showing me rocks i think theyre really nice

i wish i had a geologist friend who could sit me down and tell me everything about these rocks and what kind of rock it is and how they were formed and everything about them:(

theyre just normal rocks but i want to KNOW about them.

Yeah, I think they're gneiss.

I like rocks, anyone else like em' too?