At 03:10 PM 1/21/00 +0900, Wayne Dawson wrote:
>I remember reading that that YEC insists that fossilization can occur
>"within 100 years". It seems a little toooooooo fast. What exactly
>do they mean by "fossilization" in this context.
>
>Is this in reference to bone and other calcium based materials, as
>opposed to say cartilage or other even softer materials?
>
>Would that correspond to the most "ideal" imagined conditions
>(essentially only possible in a laboratory)?
>
>Are there any real facts at all behind this claim?
I have never measured fossilization rates, however, I would like to
make a few observations on this line of reasoning concerning
fossilization.
Asking how long it takes for fossilization to occur is analogous to
asking how long it takes to go from New York to San Francisco. The
answer is that it depends entirely upon the route and process that is
used to get there. You could get there in a few hours on a non-stop
flight. Or you could spend months or even years if you choose to go
by a slower method or indirect route (a sailboat journey around Africa
with many lengthy stops at various ports comes to mind.)
Alternatively, if you go by automobile, stop for a few days in Kansas
City, meet a girl, fall in love, get married, and so on ..., you may
never get to San Francisco. The same scenarios are possible for
fossilization rates -- except that in this analogy we have a goal to
reach San Francisco while fossilization is not a goal but simply a
fortunate consequence of the circumstances.
For example, let's talk about fossil wood. I have found fossil wood
molds in volcanic ashflows that were formed almost instantaneously.
However, none of the wood survived, all that is left is the hollow
mold. In one location I came upon, the molds were filled later with
silica to form casts of the original pieces of wood. This example,
however, may not address your concern since I perceive that the actual
topic of concern by YEC advocates is the "petrifaction" rates (i.e.
the replacement of organic matter by inorganic matter while preserving
some internal structure of the original object.)
Under ideal conditions, petrifaction can also apparently take place
quite rapidly. Such circumstances would include:
(1) a piece of highly porous wood falling into a hot spring
which is supersaturated with respect to silica, lime, or iron. (In
iron springs, I have seen red, iron-hydroxide crusts deposited on and
potentially beginning to replace wood from trailing branches of live
trees.) Under perfect conditions, I suspect that petrifaction could
potentially begin to occur within days or weeks.
(2) wood that is quickly buried by porous volcanic ashflows
and ash falls (at temperatures below the flash point of wood) and
subjected to percolating, warm, silica-saturated ground waters. I
suspect that petrifaction could begin within a few decades. (It would
be interesting to take some samples of wood buried by various recent
volcanic events, including Mt. St. Helens, and determine their degree
of petrifaction.)
However, very little of the earth's surface is covered by volcanic ash
deposits or supersaturated mineral springs. Most wood rots before it
can be preserved. Occasionally it can be preserved unmineralized for
long periods of time provided that it is protected from agents of
decay. In areas affected by glaciers of the Ice Ages (the Great Lake
States of the U.S.), I have seen well preserved but unmineralized wood
(and bone) in anaerobic peat and muck deposits. These often begin to
rot within days of being exposed to air. Yesterday, I saw a piece of
wood that had been found protruding from a retreating mountain glacier
in northern Washington state. It appeared as fresh as well-seasoned
firewood yet had been radiocarbon-dated at 5000 yrs B.P. (A date that
even most YEC's would not greatly dispute.) There is little doubt
that wood can be preserved without petrifaction for thousands of years.
Here in Denver, we have a lot of petrified wood eroding from
sandstones that are about 50 to 60 million years old (as dated by
radiometric methods on interlayered lava flows). Recently a housing
subdivision was built on a site where I had previously found petrified
wood. The petrified wood was almost always in small pieces and
although it was rather drab in appearance, contained finely fossilized
wood structures. As construction began, more and more wood fossils
were exposed. It soon became evident that the pieces of well
petrified wood were simply discontinuous fragments from within largely
un-petrified logs. The petrifaction process had been very "spotty"
and only a minor amount of the fossil wood was actually replaced.
Much of the wood was carbonized (like coal) and some fragments were
still very woody. Except for the few silica-petrified pieces, all of
this fossil wood exposed by the construction process disintegrated
within days of being exposed.
I realize that hauling out examples of "60-million-year-old"
non-petrified wood fossils will not convince any YEC advocates of a
great age to the earth since it begs the question. Nevertheless, this
last site greatly impressed upon me the enormous variability of
petrifaction rates. IMO, the degree of petrifaction, BY ITSELF, is
neither a good argument for nor against the age of the earth - it is
irrelevant. Unless we have evidence to inform us of the route and
process by which petrifaction took place, we can say very little about
how long it took to get to San Francisco. I haven't made it to San
Francisco yet -- in either sense of the metaphor.
Steve
[Disclaimer: The opinions expressed here are my own
and are not to be attributed to my employer.]
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Steven M. Smith, Geologist Office: (303)236-1192
U.S. Geological Survey Fax: (303)236-3200
Box 25046, M.S. 973, DFC smsmith@helios.cr.usgs.gov
Denver, CO 80225
--The USGS National Geochemical Database NURE HSSR Data Web Site--
http://greenwood.cr.usgs.gov/pub/open-file-reports/ofr-97-0492/
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