Evidence that the Great Unconformity did not Form Before the Strata above it

Well, I'm sure that Steno won't mind. But whatever he said, the term 'stratum' does not refer to only rock layers. We have provided you with definition of the term a few times now. Obviously. In fact, I predict that you won't accept things most of the time. Just so you understand that this is by your definition only. Again, by your definition, sure. For the rest of the world, a stratum is any layer of geological (sedimentary) material that has a definable appearance. But you said that the principles refer only to strata. In the case of cross-cutting features, that is not the case. I realize that this is a bit of a nit pick, but it does demonstrate that you do not have a good understanding of the principles. In the case of cross-cutting features, you seem to ignore them. Edited by edge, : No reason given.

Right. What can seem like a simple diversion ends up being a huge obscure mess.It all comes back to these images... and how to interpret them.Faith's position seems to be that these hilly structures must have pushed up into the layers above because layers are deposited horizontally - which I take to mean "perfectly horizontal" not even a couple degrees off under any conditions.She seems to think we are arguing that the principal of horizontality is obsolete, or in her words "compromised", but the only point is that there are circumstances where materials deposit in a non-horizontal way. So, yes it would be good to get this sorted out. Without that understanding what's the point of talking about foreset beds?HBDEdited by herebedragons, : No reason given.

I guess I would not consider unconsolidated material to be stratum, although I guess it would fit the definition (which also includes soil, so...) The important thing, though, is that by understanding how unconsolidated or loose gravels bed gives us insight as to how geological formations were formed. But if one rejects Principle of Uniformitarianism... then anything goes, I guess. Just to be clear, it doesn't have to be sedimentary does it? Ash flow would form a definable layer, as would surface lava flows. Would not those be consider strata as well?HBD

It's hard to put things behind us when you have someone committed to denying the data and redefining terms to suite one's agenda.When we read that 'strata must be deposited horizontally', we go out and find examples of non-horizontal deposition. Then we get this argument that 'those layers are not strata', so we go and get definitions of the term 'stratum'. Now, we are getting the argument that Steno didn't reference loose sediments. And that original horizontality is an immutable law.We are continually running off in all directions to find evidence against wild assertions and come back to face ad hoc arguments that are unconstrained by any evidence at all.Frankly, I don't see any resolution other than fatigue. Edited by Admin, : Add missing space after "hoc".

Sure. It all goes back to the images I posted of the Great Unconformity from McKee's book. You say that the hill structure must have pushed up through the overlying sediment because the rock around the hills was not horizontal.Here is a clip from one of those images How did that pattern form from the hills pushing up? Doesn't that look like the image I posted where the sediment source was coming from one side?edge mentioned "dewatering" somewhere back. I had not heard that term before, but I think what he may be referring to is when the materials were being compacted (which would force water out of the spaces between sediment grains). This compression would also explain some of the distortion around the sides of the hills.Here are those images again Bottom line... these images indicate that the surface labeled "Algonkian" and "Archean" were there BEFORE the overlying sediment was deposited. It did not tilt or slide or lift to produce those patterns - those are depositional patterns. The image on the left labeled "c" may be partially caused by lifting while sediment was soft and image "e" is kind of complicated, but other than those two, it should be clear they are depositional patterns.HBD

Like everyone else that has chimed in here, I find it impossible to follow the positions and definitions Faith uses regarding this issue of horizontality. I think your question is nicely worded. She wants to somehow hide behind the word "horizontal" as if it has a hard and fast literal meaning in geology and yet everyone (including her) knows that nothing in geology is going to be literally horizontal. Thus there must be some more broad meaning used.Faith harumps that it's some sort of affront to Steno that geology has added to its knowledge in the last 3+ centuries since he made his first (and quite limited) observations. Well, tough noogies - that's how science works, it continues to add knowledge to the whole. We now have Einstein's general and special relativity with no one hating on Galilean relativity. Steno wasn't a god who is not to be questioned.I'm still trying to figure out how the very law of gravity got so impacted in a few short posts.In Message 988, Faith clearly states that for layers to be deposited non-horizontally, gravity would have to be defied. While in Message 1052, she claims that it's no longer a 'breaking the law' issue, but a definitional one (both are nonsense of course). Hard to follow and looking forward to answers.JB

In a broad sense yes, I could consider them to be strata. I should not have edited my post in such a hurry. However, in most discussion we consider strata to be sedimentary.The point here is that all sedimentary strata start out as loose sediments. They may be deposited horizontally or not, often conforming to the underlying surface on which they are deposited.Then, they may be deformed by settling or sagging around a hard point in the underlying material and may actually 'pinch out' against a high point. They may also be deformed by a disturbance such as a dropstone or a slump.After lithification, strata can be deformed by tectonic forces or impacts , etc.; and be folded, fractured or sheared.The distinction Faith is trying to make between loose sediment and rock in her definition of strata is specious. All sedimentary rock started out as soft, aggregates of material that became rock at some point in time. That is why we recognize soft-sediment deformation as a style of deformation.The point about the non-sedimentary formation of the erstwhile 'dropstone' in your example is that the whole formation was moving prior to, and possibly even after, deposition. Is that pretty clear to most people? I can try to explain better, but it really is outside of our discussion on sedimentary environments and unconformities. Don't feel bad, I thought it looked like a dropstone also and only found out by chasing the URL of the photograph to its original location.

I know I'm confused. I wasn't sure which example from HBD you were referring to. Since dropstones are being used as evidence of how sedimentary layers form this might be something important, but as I'm not sure what you're saying I'm not sure if it really is important.

Exactly correct. From these diagrams, one could not prove to Faith that the basement rocks were not uplifted in some way (though if that were the case, I'm sure McKee would have drawn in some faults or something).But in the case of dropstones, it should be pretty clear that the sediments were deformed during sedimentation and there were no tectonic forces involved. Edited by edge, : No reason given.

Okay, here is the image I was referring to. It was called a dropstone at first and Faith had concocted some odd explanation of its passage through the upper layers to get to its present location by traveling diagonally through the layers rather than straight down.In a way, Faith was correct because it's not a dropstone.It is actually a fragment within a pyroclastic flow from an explosive volcanic eruption and all of the fine sandy layers are volcanic ash.Consequently this is not a sedimentary rock and the boulder is not a dropstone. As such, it really doesn't relate to our discussion because all of the material in this photograph was moving laterally (I'm not sure which direction) making the pathway of the boulder irrelevant to sedimentation.ABEHere is the original source. I think if you look at the third panorama shot, it labels some of the rock units involved. GigaPanning Kilbourne Hole - Mountain Beltway - AGU Blogosphere /ABEI believe that I gave a reference on such deposits that shows how these rock fragments can be entrained by an ash flow. Look on page 7 if these class notes.http://www.geo.umass.edu/.../volcanology/Pyroclastic%202.pdf Now, all this is not to say that dropstones do not exist, or that they do not refute Faith's notion that strata cannot fold while soft during sedimentation, or that they must be horizontal at deposition, etc., etc. We have plenty of evidence in other photographs and figures. Edited by edge, : No reason given.Edited by edge, : No reason given.Edited by edge, : No reason given.

Steno's principle isn't about the surface the sediments deposit ON, it's about the surface FORMED BY the sediments as deposited. On that page I posted he says they were all deposited in fluid state, which IS how they look when you see them in a deep stack such as in the Grand Canyon. Anyway, the principle has to do with the layer itself, its own surface, not what it's deposited on. This is why I keep pointing out that if there is a very irregular surface for it to deposit on, such as that gneiss in the road cut picture way back there, or a nonhorizontal surface like HBD's diagram of a slope accumulating sediment, or the monadnocks or hills in HBD's other diagrams, or the surface of a rock that dropped into a stack of still-soft sediments, any new deposition of loose sediment, either dry or fluid, would not form a coherent layer over or around the irregular surface but would butt up against it.Edited by Faith, : No reason given.

That's like saying "The principles relevant to paint application aren't about the the shape of the car the paint is ON, it's about the surface FORMED by the paint as it's applied."Unless you apply enough layers of paint (25ft thick?) to eventually totally disguise the shape of the car, the paint is going to take the form of the car. As more and more layers are applied, sure -- it will look less and less like the car, but the initial layers will indeed look much like the original form.THAT is the question that is being asked of you - if the deep and still bottom of the lake bed were to slope from East to West by .05 degrees, would the sediment form an even layer across the lake bed or would it somehow all magically be displaced to the West (lowest end) of the lake? How about .005 degrees? How about 5 degrees.Surely you must be able to imagine some minute angle that is close enough to horizontal where the deeply placed sediment just stays were it falls. Conversely you must be able to imagine an angle that is steep enough that WOULD cause the sediment to slip to the deep and and not adhere to the lake bed surface.What are the limits of these two angles that you are imagining?JB

No, he was addressing what strata ARE and have always been known to be until this weird idea came along that loose sediments can also be "strata," and I have no idea when that happened; for all I know this thread is its birthplace. Strata ARE those layers of ROCK one sees in the many pictures posted here, and most dramatically in the Grand Canyon. You missed the photo edge posted of the gravel on a hill? But this entire discussion is about this issue, whether layers could form BY DEPOSITION IN THEIR LOOSE STATE over an irregular surface such as the gneiss in the road cut photo or the monadnocks in HBD's diagrams and just about every other post for days now. How you can say you don't recall this is beyond me. It's just about ALL we've been talking about for pages and pages and pages... YOU KNOW NO SUCH THING, and I've been at pains to show this. NO strata DEPOSIT irregularly or nonhorizontally. DEPOSIT!!!!! Get the word "deposit." They get DEFORMED in many ways afterward, as Steno's principles are designed to recognize. I can't believe such a simple principle could become as unnecessarily complicated as it has. No, it's because Geology has lost its mind, period. Steno had more smarts than anybody here. There are NO exceptions to the principle of original horizontality in relation to the STRATA.Edited by Faith, : No reason given.

LOOSE DEPOSITS WOULD FILL UP A DEPRESSION. How do you people manage to stay upright walking around this planet anyway?

You appear to be avoiding answering the easy question:

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THAT is the question that is being asked of you - if the deep and still bottom of the lake bed were to slope from East to West by .05 degrees, would the sediment form an even layer across the lake bed or would it somehow all magically be displaced to the West (lowest end) of the lake? How about .005 degrees? How about 5 degrees.

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Surely you must be able to imagine some minute angle that is close enough to horizontal where the deeply placed sediment just stays where it falls. Conversely you must be able to imagine an angle that is steep enough that WOULD cause the sediment to slip to the deep and and not adhere to the lake bed surface.

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What are the limits of these two angles that you are imagining?

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JBEdited by ThinAirDesigns, : No reason given.