Re: Early Cambrian & Phanerozoic

Kevin O'Brien (Cuchulaine@worldnet.att.net)
Mon, 8 Feb 1999 23:07:48 -0700

>> >This may work for phanerozoic bacteria, proterozoic metazoans and
>>the early
>>>Cambrian fauna, but how does it work for the entire order of successional
>>>appearance?
>>
>>Karen: It works (and is required) if there is rapid sedimentation all
>>through the
>>geological record. The successive appearances record the succession of
>>burial, not of origin.
>>
>>And absence of any mixing or "out of order" fossils
>
>
>Some fossil forms have a short stratigraphic range, some long, some ranges
>get extended by new finds. Some are clearly reworked. There have been
>claims of "out of order fossils" that were later well-explained by
>overthrust faulting.
>What would "out of order" fossils mean?
>

How about a pod of dolphin skeletons in unfaulted, unaltered, uniform
Devonian deposits? How about a modern human skeleton found inside the rib
cage of a Tyrannosaurus rex?

>
>>Karen: The concept of hundreds of millions of years is another matter!
It's
>>based upon the premise that much sedimentation indicates much time, and
>>upon isotope ratios interpreted with that firmly in mind. Other
>>interpretations of the isotope ratios, invoked when the dates don't fit
the
>>accepted timescale, may also apply when they do.
>>
>>Please explain, the enormous evidence pointing to an old earth especially
>>from the radiometric dating makes a young earth hard to support. What
>>"other interpretations" of these ratios are there ?
>
>When the isotope ratios indicate dates that do not match the accepted
>timeframe (such as K-Ar ratios that "date" older than the accepted age of
>the earth), alternate explanations for the observed ratios are explained.
>The explanations are reasonable, having to do with realistic processes that
>I would think could equally apply to the "accepted" dates as well. These
>include, for example:
>

[snip]

>
>So it is understandable that there are many unacceptable "dates" that have
>to be thrown out. What I question is the assumption that the ones that fit
>the accepted timescale are free of these problems, and therefore accurate.
>
>It seems circular to me to accept isotope ratios as accurate only if they
>fit the expected date range.
>

But that's not why they are accepted as accurate. They are accepted as
being accurate because researchers have checked for those problems and have
not found them. In other words, the dates "that fit the accepted timescale
are free of these problems" because the problems are not present in those
samples.

>
>>
>>If sedimentation was very rapid, the geological record does not represent
>>much time.
>>
>>True, but that is contradicted by much of the evidence.
>>
>Or interpretations of the evidence.
>

You and I have wrangled over this before, but evidence does not need to be
interpreted as long as it is not ambiguous. If unambiguous data
demonstrates that the earth is old, no interpretation is necessary to arrive
at that conclusion.

Kevin L. O'Brien