Actually Ron, there are several means of escaping this oft claimed
circularity. This canard never mentions the first means of age dating rocks.
It is superposition. The rock layer on top is younger IF it is in a
relatively horizontal relationship to the rock layer below.
-------------------------
rock layer a fossil a
-------------------------
rock layer b fossil b
-------------------------
rock layer c fossil c
-------------------------
Since sediment only comes from above, the ages are Rock layer c is older
than b which is older than a. Can't tell yet how much older but we do know
that there is an age relationship. Now if the fossils go in this order as
well as the lithology, one can then say that fossil c is older than fossil b
which is older than fossil a. The circularity is broken by the fact that the
order of the strata determines relative age, not the fossil. Then of course
radioactive dating is also quite effective at escaping the circularity, and
helps determine HOW much age difference there is between the strata.
glenn
Adam, Apes, and Anthropology: Finding the Soul of Fossil Man
and
Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm