When looking at a geological timescale, typically ‘the deeper you dig, the older stuff gets’, right?
So, where does this buildup of new sediment come from?
I understand we’re talking about very large timeframes here, but I still dont really get it.
In: 19
Dirt is lots of stuff, but if you mean soil in particular, i.e. what plants and fungi grow in, it takes at least 100 years, and sometimes many more, for a centimetre of soil to form from the breakdown of stuff like decayed organic matter (plants, trees, grasses, fruit, fungi, animal remains and waste etc).
It comes from time. Everything breaks down given enough time. If you left a brand new modern car exposed to the elements in a field, or desert or up a mountain, it would be completely gone in a matter of a few hundred years. I don’t mean buried in the ground, but just totally eroded to nothing by the same forces that shape the natural world, only a lot quicker.
I went over to my elderly grand aunts place, she hadn’t been upstairs in 10 years due to age. I went up, and the dust on her dresser was about an inch deep. Multiply that by a million and you get the idea.
All of these explanations do not explain how dirt is getting on top of ruins and *staying* there.
Water Erosion is relentless and beats out anything landing ‘on top’ of ruins. The exception is when ruins are in a jungle climate.
The explanations in this chat seem to think you can leave dust or dirt on top of a large stone surface and have it stay there.
Water erosion and gravity all *pulls things down*, it doesn’t leave stuff on top.
I work with water erosion, and personally find it hard to believe any of the dust comments in here.
Absolutely not an expert, but here’s something that made me realise/understand.
I recently moved out the the country. The garden was not laid with turf, and for various reasons we didn’t get around to it in any kind of rush. Within a month or two of spring coming, the nice empty dirt field sprung up with weeds, at least four feet tall, and completely densely covered the whole garden.
It’s easy to forget when all you see is nicely mown grass lawns, but this is the more natural state. Imagine deep thick weeds coming up and dying off every year, and the amount of material that will leave behind. I think this is much more plausible than all of these people suggesting “dust” will just lie there.
It all the dust created by erosion, decomposition and things like that, it moves around in the wind or water currents until there’s a place where it settles naturally
Dirt is poop. Human eats apple, makes poop. Fly eats poop, makes fly poop. Bacteria eats fly poop, makes dirt.
The same way your room gets messy: From time to time things are just dropped and left and soon after you can’t see the floor anymore if you don’t tidy up.
HIGHLY recommend watching this YouTube series called The Entire History of the Earth I believe this video talks about how we got our dirt https://youtu.be/QbJGum0sWYE if it’s not that one then it’s this one https://youtu.be/7iO5gUGa-Yc
It’s a solid series that talks about how we got our water, theories on how life started, early plate tectonics….really fascinating stuff, complex concepts are explained very well
Rocky mountain range used to be about 2 miles higher. All that erosion drained down range that you can see it happening right before your eyes forming canyons, flat top mountains, arches, plains( no big rocks plains) and finally drained all that silt to Gulf of Mexico.
There is a known amount of space dust that reaches the surface of earth. It’s something like four inches every 100 years. In a million years, that’s 40,000 inches, over 3000 feet, sixty percent of a mile.
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