Geology- working up from basic principles.

Can anyone tell me if Walther's Law violates this principle? I understand that you "read" sediment deposited in this way from the bottom (oldest) up (youngest) -- but the strata themselves appear to be deposited laterally or even close to vertically. I've been looking at an illustration of this here.A creationist keeps insisting that this must have "thrown" geologists when they were "inventing" the fossil record. (At the moment he also thinks that dating methods have been deliberately changed in order to reflect a fanciful ordering of fossils so I doubt if I'm going to get far with him, but I'm interested in learning about this sedimentation process.)The video he cites, which appears to misrepresent Walther's Law, can be seen here (about halfway through -- first is the ol' polystrate-fossils-are-a-problem nonsense): "Drama in the Rocks" part 1Any information would be welcome, thanks.Edited by LindaLou, : added linkEdited by LindaLou, : typo

Sincere apologies, Minnemooseus. I couldn't remember where I'd had this discussion before, or with whom, so I didn't know where to look. I do remember not understanding very well, which is probably why memory fails. I've learned a bit since then and I think what you said makes more sense to me now.What's been confusing me is the diagrams I've seen. The one I linked to is not from a creationist site. It implies that to an untrained eye, the strata would look like they are in lateral layers, from sandstone onwards, and the creationists are claiming that this would have fooled early geologists.From what you are saying, it sounds to me like the layers are deposited horizontally just like we'd expect, but the depositional material changes as you move from the shoreline outwards. I think the way that diagram was made is deceptive because it makes you think that you've got layers at an angle, each of a different homogenous material, when it wouldn't look like that in real life.Am I right or still off base?BTW I've made a concerted effort on that creationist forum to post a lot of science lately and I've ended up being another evolutionist casualty; they've banned me. They have now banned all the opposition, which is funny and sad, but at least it means I can focus my time here.

Thanks for clearing this up Minnemooseus. The diagram you found, plus the scale measurements you provided, are very helpful. What threw me was the original video, which grossly misrepresents what's going on. No wonder creationists are confused if they're getting all their info from sources like that.

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You might remind your creationist friend that every geologist knows Steno's laws and Walther's laws, and what rocks look like, unlike creationist blowhards, and that they would be the first people who would notice if there was any inconsistency.

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I have, and I've shown that the internet is full of examples of geologists explaining and using these principles. This creationist's M.O. is to ignore inconvenient information, deny everything, and claim that scientists are liars and deceivers. If you were there you'd be very busy telling him about the fantasies in his head Nevertheless I will pass on Moose's info so that the readers can better understand even if the creationist stays in denial mode -- I'm told that apparently I've only lost my posting privileges because there is a glitch in the system.He thinks that all sedimentary rock shows the kind of deposition in his video because . . . there was a global flood. He's a Hovind fan too, even though I've shown him that Hovind thinks the sun burns by combustion, and that all the planets in the solar system should have cooled off by now if they are old, just like the coffee in your mug cools off (though I also had to explain why this isn't the case).Edited by LindaLou, : No reason given.

Yes. Unfortunately the quality of debate there is very poor because CTD and Russ pretend the info that contradicts them isn't there, so they never really address what you are saying -- as you know. I'm no expert but they seem totally unable to respond in a logical way to the simplest facts I've posted there.Edited by LindaLou, : No reason given.

Right -- and that makes all the difference doesn't it? The video claimed that the vertical exaggeration is how that kind of deposition happens in reality. In fact it looks like the strata are still deposited horizontally at a slight tilt. Small visual difference, big implications. This sort of deceptive misrepresentation by creationists hacks me off more than plain ignorance.This may sound like a stupid question, but can you tell me why the slope is gentle when this occurs? What happens if the slope is steeper?

I've been doing some reading and from what I understand, a slope of 10 degrees or more would cause particles to roll down the slope and be deposited in a talus at the bottom, though I'm sure this is rather simplistic.For the flood, I think YECs would argue that the particles settled out in the way we've been discussing after the flood had occurred.added in edit
Upon further reading, I'm not so sure this is right. Apparently a talus is eroded material re-deposited at the bottom of a slope, like scree from a mountain. I don't think that applies to a high gradient marine environment. I'm having a hard time trying to find how sediment in such an area is deposited. My sister-in-law is a geologist but she's in Iceland right now studying glaciers, LOL -- can't ask her.added in second edit
I've spent a lot of time on this now, without much luck. All I really need to know is how steep the slope needs to be (roughly) for the sediment to slide down rather than be deposited -- I believe this is called a bypass slope. It would still seem to chime with 10 degrees or more but I'm not sure; the papers online don't usually seem to give a degree measurement. I personally don't need convincing; it's the creationist who believes in the literal veracity of the diagram in the video. Surely sediment can't be deposited that steeply, it would just slump away.added in third edit
I think I might still be misunderstanding this whole concept. I was imagining that when sediment washes from the shore, the sand lands closest to the beach, then finer particles further out, making a horizontal stratum with differing materials as you move out from the shore. Newer layers would be added on top of this. So the principle of original horizontality would apply as usual.But the diagram Moose posted, upon closer examination, shows a horizontal timeline, which appears to be more in keeping with the video. That would seem to me to show that sand gets deposited first, followed by the finer materials in hydrological succession on top; and over time as the transgression occurs, the deposits slowly migrate shoreward. But this doesn't chime with Moose's initial post about this or other posts I've read on EvC, that say that heavier particles such as sandstone are deposited near the shore, while you need deeper water for the finest particles to settle out. This is surely describing a horizontal succession of different-sized particles (the equivalent of making the stack of plywood sheets, each offset a little in the same direction).I found this diagram, which makes more sense to me. The timelines are marked vertically through the strata.Edited by LindaLou, : No reason given.Edited by LindaLou, : No reason given.Edited by LindaLou, : No reason given.Edited by LindaLou, : No reason given.Edited by LindaLou, : No reason given.Edited by LindaLou, : Bloody hell!Edited by LindaLou, : No reason given.

Thanks for the replies, guys. Sounds like I'm on the right track. Moose, I haven't heard "local yokels" before but I'm sure my sister-in-law has; I'll ask her next time I see her. Her area of expertise is glacial flooding, called a Jkulhlaup.For your own interest/amusement, the creationist I've been debating with thinks that the video (erroneously) illustrating Walther's Law somehow explains all phanerozoic strata. He thinks it's evidence for a global flood too. I listed several other methods of sediment deposition for him and explained yet again what a marine transgression is. If you look at what the video is showing, it's sediment coming laterally or horizontally from the sea and settling in a kind of vertical order, the implication being that the facies would need to be read vertically with the oldest being near the shore and the youngest being furthest out. I suppose this could be close to the real scenario if the diagram were made almost horizontal rather than almost vertical. it then implies that geologists get fooled by facies that "appear" horizontal when the real ones are vertical. (The usual combination of scientific misrepresentation and the "scientists are stupid or liars" claim.)We've got brachiopod layers washing up into cracks in rocks on mountains and getting stuck too, LOL. This guy isn't too difficult for a layperson to deal with fortunately.Edited by LindaLou, : No reason given.Edited by LindaLou, : No reason given.Edited by Admin, : Fix link.