otseng wrote:nygreenguy wrote:otseng wrote:nygreenguy wrote:Well, it all depends on the species. The further we go back, the harder it is to find wood which meets the requirements needed to do proper ring reading. We need to find species which all have undergone similar conditions and are intact. When you go back that far, it becomes difficult simply because old things rot! I think the 10,000 break is with actual wood, or pre-fossilized and not any true fossilized wood.
Claims have been made about the broken set that has rings. Could you find information on that so we can include that in our analysis?
Im not sure exactly what you are asking for. A set older than the 10,000 year continuous one?
Yes.
Scotracer wrote:The geologists doing the work wont be so hasty to assume the layers are annual just as a matter of routine; as I said it my last post, there are ways to tell if the layers are annual or not by the structure/texture of the layer itself. And of course, counting the layers is backed up by the radiometric methods.
I would hope not. But there is an inconsistency in the claim about layers. Don Lindsay's website says that each layer is an annual layer. Micatala has also stated: "Also, the layering we see is not based on individual storms, but the seasonal changes caused by earths orbits."
I think any inconsistency is due to there being two ( or maybe more) uses of the word "layers" that has been occurring.
I agree with otseng that one might see layers formed by individual snowfall events. We could term these subannual layers. The very nice snowpit picture provided by otseng may be showing us subannual layers.
However, there are also annual layers that occur. In fact, one could simply DEFINE annual layers to be the residue of whatever precipitaiton there was during each year going back in time.
Now, the question of course is, if we define annual layers in this way, can we distinguish between subannual layers and annual layers?
I say we have presented ample evidence that the answer to this question is "yes, in many circumstances, and we can also usually tell when this is not possible."
It is evidently possible in at least some places and at some depths for trained observers to tell which layers are annual and which are not. I have provided evidence that scientists have been making observations of how layers form going back to at least the 1950's.
We also have other non-visual methods of determining where the dividing lines between annual layers are. As I alluded to above, these include comparisons of O16 and O18 oxygen isotopes. There are also other chemical methods that we could perhaps go into in more detail.
We have also presented evidence that scientists can and have checked their methods for counting annual layers with "marker events" in the record like volcanic eruptions, the onset of the industrial revolution, known past changes in climate (e.g. the Little Ice Age), etc. If their methods of counting layers was actually counting snowfall events and their were many layers per year, these checks would be way off. They seem not to be so it is fair to say their methods seem to be at least fairly accurate.
Thus, to otseng's question
I would say absolutely not. We can tell, at least in some circumstances, which layers are annual and which are not.
In fact, the Don Linday site linked to here says the following:
So, now we have a way to answer the basic question: how many layers per year? And the answer turns out to be: one. To be more precise, it is thought that in the last 50,000 years, the deviation from 1:1 is much less than 1%. That is, the best possible count to layer 50,000 would mis-date by much less than 500 years.
The oxygen ratio isn't the only method used to draw that conclusion. The deuterium ratio follows the same pattern. And then there's the ratio of Beryllium 10 to Beryllium 9. This is a little different, because Be10 comes from the upper atmosphere, not from the ocean. And, one cycle of this ratio represents a Solar sunspot cycle, which is to say, 11 years.
Note he refers to the oxygen ratio I alluded to above. There is also an 11 year Beryllium cycle against which the oxygen cylce can be checked.
Note that these two methods employ completely different mechanisms! The first depends on seasonal variations in temperature. The second on the solar sunspot cycle which is independent, at least largely so, of the temperature cycle.
So, can we agree that, while cursory visual inspection of layers, especically by those without experience, is not completely reliable, it is also not irrelevant.
Also, can we agree the
annual layers are NOT determined solely by visual inspection but by multiple and often independent mechanisms?
FInally, can we also agree that
if scientists are correctly determining the annual layers, this pushes the date for any hypothesized flood back at least several hundred thousand years?
" . . . the line separating good and evil passes, not through states, nor between classes, nor between political parties either, but right through every human heart . . . ." Alexander Solzhenitsyn
