From: bivalve (bivalve@mail.davidson.alumlink.com)
Date: Fri Mar 28 2003 - 20:19:59 EST
[Note: I will be away for a while, so do not expect rapid replies.]
>It looks like we all see what we want to see. I have re-copied from my original post and put the references to high-energy environments<
High energy environments, which was my wording, is not the best term for the issue at hand, at least with regard to my point. For fine particles in suspension to be deposited rather than transported, the flow rate of the transporting fluid must be less than a certain threshold. This can happen in a predominantly high energy environment if the flow rate is not constantly high, e.g. in a tidal channel.
>Just because the velocity may momentarialy go to zero on a beach is not rational support, as far as I can envision, for rapid accumulation in otherwise high-energy environments of very fine-grained sediment.<
Not sure what you are getting at here. I thought you were the one trying to support rapid accumulation of fine grained sediment in a high energy environment.
>Here again, a 3-day storm deposited microscopic particles. <
Every wave can deposit fine particles as it loses energy on the beach. I looked up the original Treatise reference. It says nothing about the environment in which the particles were deposited.
>The last quote is, as you said, evidence for rapid deposition of microscopic particles.<
I did not say this. The floor of a basin with high nutrient levels (which is indicated by the abundance of diatoms) is likely to be somewhat anoxic and thus inimical to scavengers, so the presence of a few articulated skeletons is no surprise.
The vast majority of fossils are in terrible condition, showing clear evidence of erosion, bioturbation, scavenging, etc. You cannot use the occasional well-preserved specimen to ignore the rest.
>How do you know what was deposited and eroded if the "deposited" strata are now gone? Why do you assume strata were "deposited and eroded"? What evidence do you have for this assertion?<
I found a relict bit of an otherwise eroded layer. Apart from that, I do not know what layers were deposited and then eroded in that particular spot, though I can make a pretty good guess by going to nearby localities and seeing what layers occur there but not at this spot. Erosion and non-deposition at the contacts is generally evident-a lag deposit, borings, epifaunal organisms, nonconformity in the bedding evident upon close examination, etc.
>What is your modern analog? I would think homogenous flat layers would be cut by river channels. <
Plains and plateaus are my modern analogs. Sure, they usually have river channels, but there is flat land between the channels that is eroding relatively evenly. The odds that a particular outcrop will have a channel running through it is less than 100 percent.
>Are you saying that the erosion was due to sheet flow (as in a Flood)?<
Ordinary rainfall will do the job nicely. However, this raises a more basic question that needs answering before this discussion can get anywhere. What is your flood model? You need to provide a coherent model and to show that it fits the evidence as well or better than conventional geologic explanations. The fact that you can find problems with any scientific theory does not automatically mean that a particular alternative is better. Likewise, invoking the Flood to do anything they want is a popular way for Flood geologists to damage their scientific credibility. For example, why would the Flood produce sheet flow? What layers were produced by the Flood?
Dr. David Campbell
Old Seashells
University of Alabama
Biodiversity & Systematics
Dept. Biological Sciences
Box 870345
Tuscaloosa, AL 35487-0345 USA
bivalve@mail.davidson.alumlink.com
That is Uncle Joe, taken in the masonic regalia of a Grand Exalted Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at Droitgate Spa
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