"polystrate" fossils and quick deposits

[ApostateAbe]

What are some ways to tell the difference between a set of geological
strata laid relatively quickly (like under a hundred years), and
strata laid gradually (like over a hundred thousand years)? I am
already aware of radiometric dating. I ask because of upright fossil
forests that seem to occupy many layers that creationists use to
object to uniformitarianism. They think the explanation that they
were deposited quickly without another way of knowing is an ad hoc
explanation.

[DJT]

As I understand it, (please note I'm not a geologist) all geological
strata is laid down one layer at at time. Layers represent a period
of time, sometimes a year in the case of varves in lakes, or flood
cycles, as in the Nile valley. Sometimes the layers represent longer
time frames. In an area that was drained in an arid climate, the
layers may be much thinner than in areas where there is more erosion
and transport of silt.

There is no hard and fast rule about how many layers equals how many
years. The cases of upright, or "polystrate" fossils, are usually
the result of rapid flooding burying a object like a standing tree
trunk. Creationists point to that, and say that since that amount of
sediment was laid down quickly, all equal amounts of sediment must
have taken the same time. Obviously that's wrong, as the rate of
formation of the equal size strata varies depending on many factors,
including sediment load, etc.

For example, if an area gets one inch of snow in 1 year, and you
count 100 inches of snow in a glacier (assuming no melting), it took
100 years for that layer to form. Suppose another area gets a
snowfall of 20 inches a year. That area will only take 5 years to get
100 inches. A third area might get a sudden bizzard that drops 20
inches in one day. It would be inapproprate to use the same measure
for each area. That is what Creationists do when they claim
polystrate fossils are a challenge to conventional geology.

DJT

[Cemtech]

In article <1180832146.7...@d30g2000prg.googlegroups.com>,
tian...@yahoo.com says...

Start here. =)

http://www.talkorigins.org/faqs/polystrate.html
--
Steve "Chris" Price
Associate Professor of Computational Aesthetics
Amish Chair of Electrical Engineering
University of Ediacara "A fine tradition since 630,000,000 BC"