You could follow the images to their source and confirm what I say. You could do a teeny bit of research to verify if what I presented has any validity. You could go to the canyon yourself and collect samples and analyze them to see if what I said holds up. Or... you could just dismiss it as irrelevant and unmeaningful.
The normal policy at EvC Forum is for all information pertinent to one's point to be presented in messages, that members shouldn't send other members on scouting exhibitions at other websites, but of course there's a limit to how trivial a claim one should be forced to support. One shouldn't have to prove that the freezing point of water at STC is 32°F, so it would be perfectly valid just to tell someone expressing skepticism to go satisfy their doubt at some physics or chemistry website. So not being sure how obvious what you're saying is, and not understanding your point because I didn't understand your image nor the arguments you presented with it, I thought I'd take your suggestion and "follow the images to their source."
I first tried to follow this image to its source:
This image is at 1.bp.blogspot.com, and I was unable to follow it to any webpage. Looks like blogspot.com is a blogging site that can host photos.
This was your original explanation in Message 227
herrebedragons in Message 227 writes:
(image above) The clasts are composed of the same material that the lower layer (layer "A") is made of and they have been incorporated into the upper layer (layer "B"). This is the evidence (there is more as well) that layer "A" was exposed to the surface and subject to erosion and then overlain with layer "B" creating an unconformity between the two layers.
This is my understanding of what you're saying about the image, but I found I had to do a lot of reading between the lines and referencing of prior posts and my own knowledge: The clasts are the white quartz-like chunks embedded at the boundary between lower and darker Layer "A" and upper and lighter Layer "B". The clasts are made of the same material as Layer "A". When Layer "A" was an exposed landscape and before Layer "B" began to be deposited here, weathering and erosion broke these clasts off from some higher elevation area of Layer "A" and carried them to this spot. Here they remained as time passed by, and when Layer "B" was deposited atop Layer "A" they became buried at the boundary between Layer "A" and Layer "B". The presence of these clasts from Layer "A" at this boundary is proof that Layer "A" was exposed to the surface, because if it wasn't then loose material could never have been weathered and eroded from it.
Also, the boundary between Layer "A" and Layer "B" is by definition an unconformity because Layer "B" was not deposited upon the topmost portion of Layer "A". Before Layer "B" was ever deposited, some of Layer "A" was eroded away.
What affected my ability to follow your argument, and it may have affected Faith's understanding, too, is your claim that the clasts are from Layer "A". They resemble Layer "A" not one bit. Maybe the clasts *are*
from Layer "A", but they have a dramatically different appearance, and further, it seems unnecessary for the clasts to be from Layer "A" in order to make the point that Layer "A" must once have been exposed at the surface.
I'm not trying to involve myself in the discussion. I'm mainly trying to make the point that if I'm having trouble following arguments, it's possible that others may also. I know geology discussions have been over this ground before, but that doesn't justify arguing in some kind of verbal shorthand.
And more clarification: I'm definitely not singling you out. I'm having trouble understanding many points from many of the participants in this thread. My intent this morning was to go through the posts since Tuesday evening and ask questions about everything I don't understand, but I'm already out of time and have to move on to other things.
One other comment: I really like the way Faith marks up photos to clearly identify which portions she's talking about.
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