quote: Suddenly the discussion in another thread about Rohl's revised chronology becomes highly relevant, because if carbon dating has been calibrated against incorrect recent historical dates, the extent of the carbon effect could be exponentially overemphasized for the earlier dates.
That's really desperate clutching at straws there. What makes you think that Rohl's ideas are even relevant ?
quote: As for other dating methods, its possible they were cherry picked for their apparent agreement.
Is it ? Are you REALLY going to stoop to conspiracy theories ?
quote: I have yet to see a convincing argument for either varves or dendrochronology being convincing arguments to strengthen current dating assumptions.
Probably because you dismiss them out of hand at the slightest excuse.
quote: Varves are often mistaken as annual, when there is a possible tidal development. Lake Suigetsu is one example where on closer analysis the varves are more obviously tidal in nature. They were formed mainly by diatom blooms, some diatoms are freshwater diatoms, sensitive to salinity. Until a few hundred years ago, these lakes were mainly freshwater, but being so close to the ocean would have been affected by rising salinity every spring tide. The ~50 000 years of varves should quite simply be divided by 12.2 to reflect the 12 spring tides a year.
Perhaps you would like to provide some evidence for that. And explain how it's even possible given the results of the study (is it really plausible that ALL carbon dates are wrong by a factor of 12.2 ?). Don't forget to deal with the other data used as cross-checks. I don't think that Lake Soppensee is likely to be tidal !
Obviously you haven't thought about it, you're just thoughtlessly throwing out an excuse without even considering whether it could reasonably be true.
quote: As for dendrochronolgy, the concept is often cited, but no convincing argument has been put forward for those periods when an overlap of ring sequences is not easily matched between trees. ie easy to make mistakes. Hoping someone can post a convincing set of data to show the reliability of dendrochronology. Also taking into account some trees show two rings per year if there are two rainfall seasons.
And more clutching at straws. Even under your assumptions C14 dating should work as a RELATIVE dating system, so we can be reasonably sure of any sequences used in C14 calibration. Any major errors should be obvious.
Occasionally producing 2 rings a year is hardly a big enough problem if you are trying to argue that the dates are wrong by a factor of 12! That should be obvious.
This brings me to the difference between scientists and cranks. Cranks assume that they are unquestionably right and look for excuses to declare that they are right (and even there they are careless). Scientists try to see the whole picture and understand what is going on. This is why science is so often right and cranks are so often wrong.
quote: Do you know how they checked that the varves in Lake Soppensee were annual?
I believe that they chose a lake where annual varves occur. Do you have evidence for anything else ?
quote: Carbon dating.... can you see the irony? Sure use carbon dating to calibrate carbon dating ....??
The real irony is that you were caught bullshitting and you're trying to bullshit your way out of it. There's a huge difference between the researchers using carbon dating to calibrate carbon dating and using other varve systems as independent checks. The actual calibration is against the varve count.
quote: You can get daily tidal varves, spring tide varves, bi-annual rainfall varves, annual rainfall varves. You cannot use carbon dating to verify carbon dating, that makes no sense. Scientists have scanned the planet to find ways to verify their dates, nothing wrong with that, but then the studies must bear all scrutiny.
There is a big difference between scrutiny and inventing bullshit. It is your attempts to dismiss the results that fail to withstand scrutiny.
The question is not whether there is some small amount of saltwater intrusion, the question is whether the varves count is significantly off as a result. You've given no reason to think that this is at all likely. Even worse this assumed error must closely match the assumed error in C14 dating, an unlikely coincidence as well. So I think we can dismiss your concern as a phantom invented solely as an attempt to discredit radiocarbon dating - and utterly failing to understand that it is insufficient to discredit one calibration - you need to discredit every calibration covering the period of your concern. When that additional data is taken into account there is no likelihood at all of a major problem at a single site going undetected.
On another point I do not think that we can be reasonably expected to be silent on your tendency to distort, misrepresent and even invent facts. I grant that commenting on your tactics may cause you some upset, but permitting you to get away with it would sabotage discussion. The best solution all round is for you to take the effort to be honest and accurate.
Hardly a general problem with radiocarbon - the problem and the cause are well understood.
quote: Diatoms naturally produce carbon. So we have to be careful to take that carbon producing effect into account when dating shells of creatures that produce carbon
No, they do not produce carbon (and the whole idea of diatoms engaging in elemental transmutation is rather silly), indeed the article says that they get it from the atmosphere.
quote: I do take the effort to be honest and accurate. Let's discuss science from now.
I cannot see that this claim is consistent with the silly misrepresentation of the Science Daily article, which isn't even relevant to the question of radiocarbon dating anything but diatoms (and if anything suggests that they would be better material for radiocarbon dating than I would expect)
quote: Thanks for correcting me, yes they produce organic carbon from carbon dioxide. This does create a problem for radiocarbon dating because fossils from organisms that produce organic carbon in their shells have to be re-calibrated to get the correct carbon dates. Was this done with the diatom fossils in Lake Suigetsu?
It only has to be done if the source of the carbon is NOT the atmosphere. Anyway, I am unaware of any dating of diatoms from Lake Suigetsu, so the question does not arise.
quote: Diatoms are particularly relevant because this is how the varve layers were determined in Lake Suigetsu, from the layers of diatom fossils. The original claim is that there was a seasonal variation in sedimentation covering the diatom fossils, I am proposing the likelihood that there were tidal water table related die-offs of freshwater diatoms that produced the diatom varves.
The diatoms provide the marking used for counting the varves. This does not make the carbon content particularly relevant. And surely a commitment to honesty and accuracy requires withdrawing your speculation once it is shown to be untenable. As had already been done before your return to this thread today.