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Author | Topic: Growing the Geologic Column | |||||||||||||||||||||||||||||||||||||||
JonF Member (Idle past 386 days) Posts: 6174 Joined: |
Not all definitions of stratum require sedimentary rock. E.g. Google "define stratum" and you get 'a layer or a series of layers of rock in the ground. "a stratum of flint"'
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
She probably doesn't know that a tuff is volcanic.
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JonF Member (Idle past 386 days) Posts: 6174 Joined:
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I get it all from geology sources, As many have demonstrated, you don't get your definition of the geologic column from geology sources.
where else would I get it? It's pretty obvious that most of your claims come from your feverish imaginings. Edited by JonF, : No reason given.
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
it does not include igneous rock and so on and so fort Every posted definition of the geologic column, and there are many here, disprove that claim. You have posted no definitions. Just assertions. Austin's paragraph is not a definition. Edited by JonF, : Removed criticism of Austin.
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
OK, you are probably right; I misread it. I've removed the criticism.
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
As far as I can see she hasn't digested any definitions. She makes 'em up. E.g. geologic column.
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
Well, my interest has been in THE Geologic Column Yeah, nothing's interesting about the facts that a geologic column exists under every location on Earth, that in some places it's eroding, in some places it's growing, and in some places not much is happening. No interest at all in the reality that falsifies your claims. Edited by Admin, : There was what looked like a failed attempt to bold the "a" in "a geologic column", so I bolded that "a". And there were some typos in the last sentence, so as long as I was editing the post I fixed them, hope that's okay.
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
Are you actually arguing that all igneous layers are intrusive?
Tuffs are not intrusive. And it's quite possible to determine when a lava layer is not intrusive.
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
It's a unique place, though, and really it's less like igneous layers between sedimentary layers than sedimentary layers between igneous layers since the area is a huge volcanic province. OK. So you were wrong when you claimed no such thing existed. And there's no difference between "igneous layers between sedimentary layers" and "sedimentary layers between igneous layers"; they are just igneous layers followed by sedimentary layers followed by igneous layers... Of course it's not unique. From Geochronology of the pre-KBS Tuff sequence, Omo Group, Turkana Basin (all but the abstract is paywalled) here's the stratigraphic sequence near Lake Turkana (nee Rudolph) where many hominid fossils are found:
Note that tuffs cannot be intrusive. From How do we know the ages of fossils and fossil-bearing rocks?, explaining that it's non-intrusive igneous layers that are used (mostly) to date sedimentary rocks:
(Again ash layers cannot be intrusive) And from Strangers in a Strange Land: Tuff luck, it's all your fault, so don't be an ash about it (you really should click that, it has a simple and great explanation of why that black layer isn't intrusive):
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
It's a unique place, though, and really it's less like igneous layers between sedimentary layers than sedimentary layers between igneous layers since the area is a huge volcanic province. OK. So you were wrong when you claimed no such thing existed. And there's no difference between "igneous layers between sedimentary layers" and "sedimentary layers between igneous layers"; they are just igneous layers followed by sedimentary layers followed by igneous layers... Of course it's not unique. From Geochronology of the pre-KBS Tuff sequence, Omo Group, Turkana Basin (all but the abstract is paywalled) here's the stratigraphic sequence near Lake Turkana (nee Rudolph) where many hominid fossils are found:
Note that tuffs cannot be intrusive. From How do we know the ages of fossils and fossil-bearing rocks?, explaining that it's non-intrusive igneous layers that are used (mostly) to date sedimentary rocks:
(Again ash layers cannot be intrusive) And from Strangers in a Strange Land: Tuff luck, it's all your fault, so don't be an ash about it (you really should click that, it has a simple and great explanation of why that black layer isn't intrusive):
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
To me this is unique. Obviously. But it is far from unique on Earth. And yet you have claimed that all sedimentary layers were in place before these igneous layers formed. There's a lesson to be learned from that if one were interested in learning. Edited by Admin, : Fix typo.
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JonF Member (Idle past 386 days) Posts: 6174 Joined: |
The main evidence I have is what led me to this pondering: the fact that in many or most places I've seen on cross section the volcanic effects clearly occurred after the strata were all in place You have ignored the majority of the evidence. E.g. Message 214:
Count the tuffs which cannot be intrusive interspersed with sedimentary layers.
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JonF Member (Idle past 386 days) Posts: 6174 Joined:
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I'm not sure what to do with your diagram You really couldn't figure it out? It shows seven stratigraphic sequences in the vicinity of Lake Turkana (nee Rudolph) with lines connecting tuffs shared between the sequences. The point is that in this relatively small area there are about 22 igneous tufs interspersed with 34 or more sedimentary layers. All the sedimentary layers were formed after at least one of the tuffs. All of the tuffs formed before all of the sedimentary layers are in place. This thread is about growing the geologic column. It's not restricted to timespans of hundreds of millions of years. Perhaps this discussion would go better in your other thread if you ever fix it up (especially by noting the many refutations of your original first post). You are doing some serious goalpost moving. Message 270:
quote: That diagram falsifies your claim.
Message 233:
quote: Igneous layers are often not intrusive when found between sedimentary layers.
Message 187:
quote: Falsified many times. There's more, but you won't read this anyway so it's not worth the bother.
When I'm talking about volcanism after sedimentary deposits I'm looking for the deepest stack of sediments I can find because I'm trying to make a point about the hundreds of millions of years before tectonic or volcanic disturbance You've made it clear that you think that there are no non-intrusive igneous layers. There are. There have not been (in general) hundreds of millions of years before volcanic disturbance because the figure shows clearly that there have been volcanic disturbances 1.8 million years ago and many more older but still much less than hundreds of millions. Individual locations on Earth may not have experience any volcanic or tectonic disturbance for a long time, but you cannot generalize that because in general it's been falsified.
But your diagram, which required me to look things up The diagram stands by itself. If you feel the need for more background information, tough noogies. This is a discussion forum, not a tutorial on demand forum. Posters may choose to explain in great detail, but you are ultimately responsible for learning enough to discuss.
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JonF Member (Idle past 386 days) Posts: 6174 Joined:
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How is it moving goalposts to be looking for a whole deep stack of layers for my examples, which I've clearly defined as my goal many times? IIRC your first mention of such is today. I could be wrong. But the topic of this thread is not restricted to timespans of hundreds of millions of years. The main part of it has been trying to get you to admit that there are many examples of many sedimentary layers deposited on top of many non-intrusive igneous layers. Of course you'l never admit that, and your goalpost moving today suggests that you are running away from it. Look for the deepest stratigraphic sequence all you want, you can't show that in general igneous layers are always intrusive and not part of local stratigraphic sequences because that's been incontrovertibly demonstrated.
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JonF Member (Idle past 386 days) Posts: 6174 Joined:
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I didn't mean it ALWAYS has to be dikes and sills, of course it CAN just flow and deposit wherever. I was answering HBD's apparent idea that it isn't an intrusive when you find it as a layer between sedimentary layers. Igneous layers are often not intrusive when found between sedimentary layers. No, in Message 226 HBD was clearly saying the opposite; listing several examples of multiple non-intrusive igneous layers between sedimentary layers. You are the one that is arguing (as far as anyone can tell form your muddled messages) that igneous layers are not part of a stratigraphic sequence because they are always intrusive.
Because I did get convinced that all this occurred after the strata were laid down so I continue to look for how that could be evidenced
That diagram falsifies your claim. Anywhere in the stack it falsifies your claim that igneous layers are not part of a stratigraphic sequence because they are always intrusive. Especially sub-aerial tuffs are a major problem for you; how many rimes did your fludde recede and return in the Lake Turkana region? Looks like at least 22 to me.
the USUAL case with lava layers in the stack called the geo column is intrusion. Show us the statistics. (I'm not claiming any particular frequency for either case, but obviously neither case is unusual)
The examples I'm finding online for my purpose all show what I call the geo column, sedimentary strata in a block variously faulted and so on but in a block Ah, the tell-tale "for my purpose" tells us that you are ignoring all that does not fit your preconceptions.
You all are finding UNUSUAL cases. The Deccan Traps are not the usual geo column and neither is your example The Deccan traps are pretty unusual (though not unique), but my example is typical of many places.
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