Counting rings on live bristlecone pines will get you back over 4000 BP and
can calibrate 14C as well.
Increased radiation makes 14C dates too young, not too old. For example,
thanks to atmospheric nuclear bomb tests, living organisms would be
carbon-dated at about 2200 to 2300 AD if no corrections were made.
Also, 14C in the oceans today takes several hundred years to get from the
ocean surface to the deep Pacific. If the oceans were more stratified (as
in Woodemoreappe's attempt to allow for organisms of different salinity
tolerance), the rate of 14C reaching the deep ocean would be slower.
(Incidentally, such stratification would suffocate many organisms in the
lower layers, because it hinders oxygen circulation as well.) With
circulation rates not much more rapid than today, deep-sea 14C should show
a lag behind surficial 14C if the ratio were rapidly changing.
If the waters were more mixed, as should result from asteroid showers, 45
mile per hour plate motion, and other things envisioned in many flood
scenarios, then there should be little stratification between deeper and
shallower-water isotopes. However, with only rare exceptions (a brief
interval in the late Paleocene is the only exception I know of, when ocean
circulation patterns shifted in a brief period of rapid mixing),
deeper-water organisms show systematically different isotopic ratios,
similar to the modern differences between shallow and deep water.
Foraminifera have been particularly studied in this regard.
>The correlations between sections of tree rings is done by statsitical
>analysis assisted by C14 dating of the sections. Thus, any inflation in
>C14 dating is transferred to dendrochronology.
However, within any one log, counting the rings and comparing them with the
14C data will tell if 14C was changing rapidly, whatever the age of the
log. Atmospheric mixing is rapid enough to prevent major differences in
the 14C ratio for contemporaneous trees. Unless no trees were growing
while 14C was rapidly changing (or if the growth of the trees and formation
of rings compensated for the rate of 14C change, which is even less
plausible), it should be possible to find traces of such a shift in 14C