From: bivalve (bivalve@mail.davidson.alumlink.com)
Date: Wed Mar 26 2003 - 13:19:19 EST
In addition to the details of the arguments, there are two fundamental problems with the reasoning. First, evidence of rapid formation of a particular feature is not inconsistent with an old earth. During four and a half billion years, there is plenty of time for some things to happen rapidly. However, evidence of slow formation is incompatible with flood geology or a young earth view, which require everything to have happened quickly (by geologic standards) and all at once. Thus, YECs have an inherent disadvantage in their arguing.
The second general difficulty is that one apparent discrepancy with the conventional old-earth view proves a young earth, whereas numerous discrepancies between young earth claims and the physical evidence do not suggest anything about their reliability.
>OK, I will yield on the articulated bivalves. I don't see that they help either view.<
Many bivalves do provide evidence against flood geology in that they lived for several years somewhere in the middle of the geologic column. Biogeographic, stratigraphic, and environmental patterns can also pose difficulties, e.g. the freshwater or shallow water bivalves would not be living happily on the bottom of a turbid, mountain-covering flood. There are also several nice evolutionary transitions within the bivalves.
>Fossiliferous limestone samples I have do commonly show evidence of laminar bedding<
At what scale? The fossiliferous limestones that I work on (certainly not a generally representative sample but a specific set of deposits) can have distinct phosphatized surfaces, but these are not flat. They represent erosion and chemical alteration as hardground surfaces, with possibly some karstic influence. Thus, there are thin, distinct surfaces that are laterally extensive through the limestone, but they are diagenetic rather than sedimentary features and indicate long time intervals rather than short ones.
>I have seen a couple of references to deposition of fine-grained sediment in high-energy regimes, so I'll take issue with your statement above. "Tidal channels lined with coral rubble between the Florida Keys have been oberved to accumulate a much as 10 cm of lime mud during such events, in spite of the fact that these are areas of high energy where normally only rubble and sand accumulate."<
Events such as what?
>"Deposits of lime mud as thich as 20 cm and abundant lime mud intraclasts are interbedded with ooid and in a tidal channel in the Exuma Islands (Dill and Steinen 1988), where tidal currents as high as 100 cm/sec occur daily (Dill et al. 1986)." (from Whitings, A Sedimentologic Dilemma, by Shinn et al, Journal of Sed Pet, v 59, no 1, Jan 1989, p159)<
Tidal channels, where the flow rate varies from high to low, can produce alternating layers of fine and coarse sediment, given enough time. Time and tide may wait for no man, but they do not speed up for him, either. The intraclasts are chunks of mud rather than suspended sediment and are indicative of high flow. Whitings have been suggested to be precipitation in the water column, which will not explain layers of fine-grained clastics.
> I have seen a well-preserved fossil bird and many fish in thick beds of microscopic diatoms near Lompoc, California. A whale was also found in this deposit.<
I have seen millions of poorly preserved fossils. The occasional nice specimen gets more press, but it is not representative.
>Such preservation would require rapid burial before disarticulation of the organism would occur.<
Or deposition in a place that was inimical to scavengers, such as the bottom of a basin with high nutrient input, leading to abundant diatoms and seafloor anoxia.
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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