WARNING: As often happens I came back and added some material to this post. Sorry, a habit I have to break.
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I guess I'll have to take my break later.
Faith writes:
The sketch of the first 2500 years is accepted as foundational (although I believe the original landscape would already be rock and any buried creatures already fossilized, but that's not an objection I want to make at this point; For now I'm accepting the scenario as given).
Understood.
If you'd like, we can consider this entire example as "how geologists see the rocks."
It isn't necessary to consider this example as "reality" if you don't want to.
The point is to show that what geologists think is an idea that is continuous and can stand on it's own.
The point isn't to convert you to "geologism" or "evolutionism" or anything like that.
I'm not concerned about any of that. What I had in mind was trying to work with what I understand geologists say about all this so we're fine.
And you haven't defined what kind of sediment for some reason -- the same as the original landscape's?
I haven't defined what kind of sediment because I don't know what the different kinds mean and I am hesitant to claim something I don't understand.
I am hoping that there is some sort of "terrestrial sediment" that you acknowledge exists, and we can consider it to be that.
If you think this is an important sticking point, we would have to take a side-track into the "rock cycle" (sort of like the "water cycle" but with rocks) and sort of start to understand where sediment comes from and add to the scenario to incorporate those specifics.
But if you just want to look at the sediment becoming rock without destroying the surface, I think we can proceed if you're okay with accepting "sediment is accumulating."
The problem is that the rocks in the stratigraphic column are clearly different from each other. I don't think we need to go into all the details as long as this fact is taken into account. If the sediments accumulating on the original landscape are the same as the landscape's then we can just leave it at that for now: The original sediment plus the accumulated sediment will then all belong to the same rock in the end.
There is another problem in that the rocks are generally made up of a fairly uniform kind of sediment, all sand, say, or all clay and so on, which is not the case with landscapes. Even though there are some exceptions and there is some mixture in the strata here and there, for purposes of this discussion I think we should think of them as all clearly different from each other, since they are different enough to make that statement, so we can't go with some kind of generic soil. Whatever it is has to be what we see in the rock in which the clues are found to this particular landscape. Again it is a sediment, not a soil, and that is already a bit of a problem for the idea of the rocks being a representation of a landscape, since landscapes, at least landscapes with a variety of plants and animals, are not single sediments; but for now let's just leave that too.
Anyway, if you had a different kind of sediment accumulating on the original landscape then it would have to be a different rock in the end. I've argued that if it isn't a landscape itself and doesn't contain fossils then it isn't to end up in the column at all and will have to be eroded away. But since you've had the landscape simply growing up through the new sediments I'll just leave it for now as one rock representing the original landscape. I hope this is clear but obviously it gets pretty complicated pretty fast.
Faith writes:
Here we start to have problems it seems to me. If the original landscape has begun to compress under twenty feet of sediment, then under forty feet of sediment it should not only be more compressed but sediment right above it should also be compressing quite a bit since it is under almost forty feet of sediment too.
You're absolutely right.
In my scenario, we have rock at 2 million years and 1600 feet deep. Let's say that is "100%" finished becoming rock.
Then at 50 000 years and 40 feet deep we would be 2.5% of the way there.
At 25 000 years and 20 feet deep we would be 1.25% of the way there.
At, say, 37 feet deep (46 250 years) we would be about 2.3% of the way there.
The entire process is ongoing and continuous if the sediment accumulation has no break in it.
This example is very simplified because it uses a rate of sedimentation that never changes. However, in any real-life areas there is no "steady rate of accumulation" that lasts forever or all of earth's history (that I'm aware of). There can be a bunch of sedimentation, then some erosion, then some stagnancy, then some more accumulation, or any other conceivable order. Each change of state will add complexity to the required explanation.
I was going to get into things like that after we look at (and possibly agree on) how "at least one rock" could form with this simple example.
Actually I'm OK with that. At first I thought your depth was too much but I realize there are rocks in the column that are that thick so that problem is no longer a problem. So I'm OK with calling this the formation of one single rock in the stratigraphic column, the sediment all being the same sediment, fossils accumulating according to whatever environment this represents and so on.
Again, the numbers used in my scenario are made up by me, only taken from what I can see are "generally accepted" values from the geological community. I understand that these values are very slow and maybe even "seemingly impossible" for you to accept... but they are what geologists say are required to explain the things we see.
Whatever problems I have with any of this I don't think are crucial to the overall situation I have in mind so I'd just like to leave it at this.
This is one problem I've mentioned a few times in relation to the idea of lithification of a landscape under accumulating sediments: at some point those lithifying sediments must start to get lithified as well. But as I've thought about it, they don't belong in the stratigraphic column that the original landscape is to end up in, so they would have to be eliminated at some point. Which becomes problematic if they are lithified as well. I recall that you are going to include them in the column eventually, but you haven't given any justification for this yet. But let's continue and see how things develop.
Right.
And the problem is because the "column" generally discussed isn't created under the extremely simple constant-rate of sedimentation I've used for this example.
I don't think that's the problem, as long as we keep in mind that WHATEVER sediments we are dealing with DO have to end up as rocks in the column, and those are characterized by particular sediments with particular fossil contents that are interpreted as originating in a particular environment.
Again, I'm only using this constant-rate for this first example in order to show how "a landscape can become a rock."
Once we agree on how geologists say such a thing can occur, we can then add things to the scenario to create "stacks of rock" and even "stacks of rock at the surface" and other such things.
But those are more complicated, so I thought it would be best to start with the most simple starting example - creating "one rock from a landscape."
I'm OK with all this.
Well I'm following you but starting to have questions about it all in relation to the final result of the stratigraphic column.
Good.
I think you have in mind a specific stratigraphic column that is created by a series of events that will be more complicated that this first, simple example.
That's okay, and we can get into that later.
For now, I suggest that we finish this current simple example and understand the stratigraphic column that is created by it and then we can move onto a more complicated one. Does that sound acceptable?
Again this is fine. I'm not expecting the probems I have encountered to show up until later in the scenario.
(Aside: I would expect it to be thoroughly lithified by now myself, not just "beginning to feel some weight and pressure on it..." due to the great length of time probably more than the weight of the sediment, but I'm not making this an issue here.)
I understand your issues with "accepting longer geological timescales" and such.
I think we should simply consider my examples as "the way geologists think it happened" as opposed to some sort of firm "accept this as reality or I'm going to be angry" thing.
I would like to alter the numbers to accommodate you here, but I don't think I can. If we're going to go through things to see how geologists view things, I think we'll have to use numbers at least acceptable to geologists. Let me know if this is going to be a problem.
Okay, let me know if we're still on the same page or not and we'll move on from there.
Carry on.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.
™ Version 4.2
