HELEN
OK, folks, let’s talk dendrochronology first, which is used to ‘support’ and ‘confirm’ C14 dating and which was appealed to in some of the responses to my post:
I have a Japanese black pine in my front yard. It is 15 years old (or 14, I forget which summer I planted it now). Growth spurts on these pines are extremely easy to see as they put on what are called 'candles'. For the first few years when the yard was new and we were using lots of water to help things get established, that tree put on two sets of candles a year, one large one in the spring and a shorter set in the late summer. So for a number of years it was putting on two rings a year.
In the same front yard, we have a small stand of birches. They were all planted as one-gallon saplings within a couple of months of each other. Three on the east have trunks with diameters of a foot to eighteen inches. Planted at the same time, in the middle of the grove, are a couple with trunks that have diameters of less than three inches. Now I presume they would have the same number of rings, however those which have had less sunlight, due to being in the middle, would have rings jammed quite close together which would not correlate at all with the rings on trees within feet of them which were planted at the same time and have received the same amount of water.
In the tropics, however, there are often NO growth rings, as there are no seasonal changes. So, obviously, growth rings are highly dependent on the environment.
One student of mine was very interested in forestry and I got him a volunteer job with the Forestry department near us. At that time I had the opportunity to ask some of the men in the lab where he was working about the growth rings. The man who responded was the senior member of the team and he honestly laughed first and said it was one of the biggest fakes he knew of -- if the weather was decent (i.e. summer rains, which the mountains usually have here on a consistent basis in the afternoons several times a week or at least once a week through the summer), they expected two growth spurts on the young trees per season.
With that under my belt, I began doing a little of my own research into this dendrochronology business. Here:
http://www.emporia.edu/earthsci/student/nang/treering.htm
http://www.apologeticspress.org/rr/rr1993/r&r9310a.htm
http://www.grisda.org/origins/22047.htm
from a private email:
"So-called "annual" rings of tree growth is a simplistic 19th century concept (like Darwinism, Marxism and Freudianism). Actual ring growth is seasonal and there can be multiple rings per year and missing rings in some years. Also, the idea that living organisms including trees grow identically under the same environmental conditions as if they were assembly-line machines is also simplistic and another 19th centuryism. When have we ever seen control studies showing tree rings cored from a grid sampling of trees at different sites showing identical or similar patterns due to a supposedly uniform hemispheric "climate"? If such a thing existed we would see it everywhere, in textbooks and popular science mags to "prove" the scientific validity of dendrochronology. It is my understanding that bristlecone pines on different sides of the same mountain near the California-Nevada border have tree ring patterns that do not correlate.
Finally, Jesse Lasken at the NSF has published several papers showing
that dendrochronologies built up from correlated sections of dead trees are actually based on correlation coefficients that barely exceed random values."
Yes, California and Nevada have distinctly different climates due to the Sierra Nevada mountains which form the border. Here in the north, we get the rain, they get the desert!
A series of emails from someone who has been engaged in this field of study confirmed the unreliability of this method of dating as quoted below:
I spend many hours studying annual growth rings in trees.
1. Yes, sometimes a tree yields more or less rings when cored from different sides of the stem (trunk).
2. In the tropics annual growth rings may be impossible to detect. Or there may be two rings per year. I have seen these effects while inspecting cut timber in Brazil.
3. False annual rings can occur. Very unusual weather, such as an early cold mass followed by very warm temperatures, may cause a false ring.
4. Tree ring people emphasize the trunks. I have found there is considerable data in the branches that is lost to integration in the trunks.
5. Coring trunks, in my opinion, is vastly inferior to studying entire cross sections. The obvious problem is that the latter requires killing the tree. This is another advantage of studying cut branches.
from someone else who has been involved in science:
I bored hundreds of pines here in Arkansas doing a research project on the Southern Pine Beetle a few years back.
Some things that could cause differences include insect attacks which damage some trees and not others, forest fires, which do not damage all trees equally, and tornadoes. Rings are very hard to see sometimes on fresh new cores. I cannot imagine accurate counts, let alone reliably matching cores, being possible in six thousand year old, dead wood.
Tree ring patterns can be expected to match only when the trees are growing in the open in identical conditions. If a pine is suppressed by the shade of a nearby tree for part of its life, or damaged by something that does not affect its neighbors, it will have a different pattern.
As a matter of fact, the pattern can be different on a different core from the same tree, if one side of the tree is damaged and the other is not.
Along this line is something my husband and I saw when we took a walk through the John Muir Redwoods last spring. On rather large tree had fallen, at some time in the past, across the walking path and the section on the path had been sawed off and removed. This left a lovely view of the cross section of the rings which had then been marked by the rangers showing dates.
We saw a problem that we were sure others must have seen as well: the growth patterns on opposite sides of the center were extremely different, with one side bulging WAY out and also containing significantly more rings!
Now, regarding carbon 14 itself, production of 14C influenced by changes in the sun’s activity, supernova explosions, and changes in the earth’s magnetic field – at the least.
Climate changes and the use of fossil fuel are factors changing the content of carbon 12 in the atmosphere.
The reservoir effect, which is also important here, is affected by volcanic outgassing as well as the carbon isotope movement in the oceans themselves.
As someone else put it, “The way 14C content is estimated into the past is by measuring 14C in wood dated by year-rings. Any serious discussion about radiocarbon should soon become a discussion of dendrochronology.”
Only part of which was discussed above.
C14 curves were mentioned. The depend entirely on the same processes going on today as have always gone on, and at known rates. This is a presumption which I do not think can be well-supported. It is a presumption relying on other presumptions.
As far as argon goes, argon migrates easily, is produced in magma flows, and there are other problems as well. There have been a number of published articles about the unreliability of argon dating. One very good one is by Andrew Snelling here:
http://www.icr.org/pubs/imp/imp-307.htm
I edited an article by a French geochemist last year (which I hope will be in print soon so we can reference it!) which pointed out with details that the argon dating of the Olduvai Gorge material was wildly different from other forms of dating the same material and would really cause a difference in the so-called evolutionary development ideas of man as a result.
The most consistently accurate results I have heard about regarding radiometric dating are from zircon crystals which are unblemished. They do not allow significant migration of elements evidently and their correlation factor is quite high.
What I was trying to tell Margaret, in other words, was that she would do much better to stay away from both C14 dating and anything to do with argon for known reasons in the literature, while arguments for the evolutionist/long-ager dealing with other forms of radiometric dating hold up much better under analysis.
With apologies to Paul of Eugene, I will try to respond in more detail to your post in particular later. Time does not permit right now. Thank you for it, though.