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Author Topic:   14C Calibration and Correlations
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Message 1 of 2 (574072)
08-13-2010 9:50 PM

From Uranium Dating Message 102 where it is off topic:
Hi archaeologist and welcome to the fray.
It appears you have a lot to say and no embarrassment about whether it is correct or not.
While these values do not compute an age for the Earth, they do establish a lower limit (the Earth must be at least as old as any formation on it). This lower limit is at least concordant with the independently derived figure of 4.55 billion years for the Earth's actual age
the bolded parts are a very big assumption ...
Denial is not refutation.
Conceptually it is entirely logical and consistent that some evidence of age can be less than the actual age of the earth, however it is not possible for evidence to be older than the earth.
This is not an assumption, it is an objective, impartial and unbiased logial conclusion
... and cannot be verified nor confirmed. such conclusions mean nothing.
Let's start with the basics: what we can know from annual layer counting from various sets of information. Consider these bits of information and see if you can explain why they correlate so well:

Tree Rings & C-14 correlations

There are three long continuouse (unbroken from today) dendrochronologies (and a lot of short ones) and one (of many) "floating" ones (where they are not directly connected to today), and they are:
  1. The Irish Oaks, extending continuously back over 7,000 years before the present day (2010).
    JSTOR: Access Check
    A major radiocarbon calibration excercise was carried out between 1975 and 1985, and preciesely dated samples of irish oak were obtained for all periods back to 5,000 BCE (7,000 years ago)
    More work has been done since then, however this is sufficient for this excercise.
  2. The bristlecone pines, including two trees that are over 4,000 years old in continous growth to the day measured, and overall to an age of ~9,000 years before the present day (2010).
    Fachbereich Biologie : Universität Hamburg
    The "Methusulah" specimen was sampled (by boring) in 1957, the measured germination date is ~2,832 years BCE, so by this one tree alone the minimum age for the earth is 4,8342 years (in 2010 ... and counting).
    Requested Page Not Found (404)
    The "Prometheus" specimen was was 4,844 years old when it was cut down in 1964. This is a minimum as the core of the tree had eroded away, and this gives a latest germination date of 2,880 BCE. By this one tree alone the minimum age for the earth is 4,890 years (in 2010 ... and counting).
    Dendrochronology (7)
    The bristlecone pine chronology in the White Mountains currently extended back almost 9,000 years continuously in 2007 (no updates on additional data since then). That's to 7,000 BC!
    Again, further research has likely extended this chronology, however this is sufficient for this excercise.
  3. The Geman Oaks, extending back continuously over 9,197 years before the present day (2010).
    The German and Irish oak chronologies were cross-dated until back into the 3rd millennium BC (Pilcher et al. 1984), and the German oak chronologies from the Main River, built independently in the Gttingen and Hohenheim tree-ring laboratories, cross-date back to 9147 cal BP.
  4. The German & Swiss Pines, a floating dendrochronology, that is cross-linked to the oak chronology to extend the combined unbroken chronology to over 12,460 years before the present day (2010).
    Not Found (10)
    The German Preboreal pine chronology has been linked and cross-matched to the absolutely-dated oak chronology. These pine chronologies from Switzerland and eastern Germany extend the measured age back to 12,410 cal BP.
Now the accumulated counting error between the two oak chronologies was 41 years over 8,000 years of cross-linked data comparisons - an error of 0.5% - and between the bristlecone pine chronology and the is off from the combined oak chronolgy by 37 years in 7,600 years of cross-linked data comparisons (younger than the oak average values) - also an error of 0.5%.
These chronologies are then used to make a calibration curve for determining a more likely actual age from the 14C age calculations. To do this they took samples from the tree rings and measured the actual 14C values. The amount of 14C in a tree ring is locked in by the growth of the tree, and represents the amount of 14C available in the atmosphere when the tree grew, when corrected for decay.
Not only was there only a strong correlation between the three dendrochronologies, there was also a strong correlation in each one with the actual amount of 14C left in the tree rings. When calculated for radioactive decay and compared to the dendrochronology they showed this calibration curve:
Note that the curve has almost continuous small jagged variations around a smooth curve.
The production of 14C is related to cosmic ray emmisions from the sun:
How Carbon-14 Dating Works | HowStuffWorks
Cosmic rays enter the atmosphere in large numbers every day, and their interaction with the atmosphere causes 14C to be produced at a rate proportional to the amount of cosmic rays that penetrate the atmosphere.
Over long geoplogical periods, changes in the long term climate can affect this proportion to a slight degree (the long term trend in the graph).
Solar cycle - Wikipedia
The production of cosmic rays also varies with a solar cycle of ~28 years. This cycle is responsible for the small jagged teeth in the graph.
In addition to age and 14C, the tree rings record the climate for each year that the tree grew.
The correlations you need to explain then are:
  • between each of the oak chronologies for age and climate changes and patterns,
  • between the bristlecone pine and the oak chronologies for age and climate changes and patterns,
  • between the irish oak and 14C age,
  • between the bristlecone pine and 14C age,
  • between the german oak and 14C age,
  • the 14C ages between each of these sets,
  • the correlation between each dendrochronolgy, 14C age, and the solar cosmic ray cycle.
Note that this last item acts as a clock check on the other data, a steady clock tick of solar cycle in each set of data confirms that the same solar cycle is in effect in each one, and also shows that there has been no change in the rate that the clock ticks.
As noted, the accuracy of this data is +/-0.5% maximum in absolute age. The possible error in 14C age is higher due to the 28 year cycle jags such that a 14C date can correlate with 3 different points on the curve, however the overall accuracy of 14C dating with this calibration is less than 10% maximum.
The tree ring chronology is continuous and unbroken for 12,460 years before the present day (2010).
And this is only the begining of the correlations that validate 14C.

Lake Suigetsu Varves and 14C

This is a single chronology formed by alternating biological deposition (diatoms in summer) and sediment deposition (clay in winter). The clay is being deposited all year, but settles slower than the diatoms, so in the summer (when a lot of diatoms grow and die) there are more diatom shells than clay, while in the winter (when diatom growth is halted) there is more clay deposited than diatoms.
Just a moment...
If the above link is not accessible try Lake Varves
This is another floating chronology, but it is over 29,000 years long, and it overlaps and lines up perfectly with the dendrochronology above. The annual varves run for a period of 29,100 years (from 8,830 back to 37,930 cal yr BP when aligned with the tree chronology).
The varve layers continue down below the limits of C-14 dating to ~100,000 years, however the data below 37,930 cal yr BP level uses an estimated rate of sedimentation rather than actual layer counts. Using only the actual layer counts we end up with either of these two scenarios:
  1. This chronology does not overlap the one from the tree-ring data (in spite of several thousand years of matching Carbon-14 levels), and the minimum age of the earth is 12,460 + 29,100 (+/-) = ~39,560 (+/-) years old (and likely more depending on the length of the gap), OR
  2. These chronologies do overlap, as determined by matching the "C-14 age" curves, and the minimum age of the earth is 37,930 (+/-) years BP (1950) = ~35,980 (+/-) years old in 2010.
Here's the combined calibration curve:
Where the green line is the calibration curve from the tree rings shown previously, and the blue circles are the data from the lake varve samples (from organic matter deposited in the layers).
The data from the lake is taken from one long core and four shorter cores, taken from different locations in the lake, and thus there is a lot of samples up to ~20,000 years ago and then fewer samples after that, but all the samples still fall on a general curve. The multiple cores also eliminate the possibility that a mud slide could contaminate the data and cause false layering (a common creationist attempt at discrediting the data).
Now the problem for you is not just the correlations between the dendrochronologies and the lake varve chronology, but with the rate of sedimentation - the deposition rate of the layers - with the 14C concentrations:
This graph shows the varve and 14C chronologies as a function of depth. As shown, the sedimentation or annual varve thickness is relatively uniform (typically 1.2 mm yr-1 during the Holocene and 0.62 mm yr-1 during the Glacial). At the end of the glacial period the rate of deposition changed, as would be expected when less water is tied up in ice and the climate warms.
The correlations you need to explain then are:
  • between the varve age and 14C age,
  • between the varve age and deposition rate change with climate,
  • between the 14C age and the deposition rate change with climate.
Note the correlation between C-14 and depth with C-14 and varve count. See how at about 11,000 years ago ("BP" means "before present" with "present" defined as 1950 CE), both show a matching change in slope of the curves with depth.
When you realize that one is a linear system of varve counting and the other is a mathematical model based on actual measurements that are along an exponential distribution:
Graph of actual 14C content versus actual time intervals from time "X"
There is no rational reason for the 14C curve to make the same change in slope at the same time as the varve age curve, unless it measures the same thing that the varve counting does - age.
This is another example of internally consistent correlations of three sets of information from the same basic data source: age, depth and 14C/12C radiometric age.


This is just a small sampling of the objective data that shows a consistent and intercorrelated pattern of age. This data does not extend back to the extreme age of the earth, but it does extend back to well beyond any creationist YEC age known.
Curiously, the actual age of the earth does not need to be proven to be extremely old to falsify the typical YEC assertion, it just needs to be sufficiently old that the YEC position is untenable.
This data does that.
Once you accept that the YEC age is false, then we can move on to other information on how old the earth really is.

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Message 2 of 2 (574074)
08-13-2010 9:53 PM

Thread Copied to Dates and Dating Forum
Thread copied to the 14C Calibration and Correlations thread in the Dates and Dating forum, this copy of the thread has been closed.

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