Thank you SoSick for your valuable contribution.

A common name for this next species of tree, this time from Europe, is "Post Oak" due to its natural resistance to rot thus making a good material for posts in ancient constructions. This also means that there are a lot of samples that are referenced to and associated with archaeological finds, finds that can be dated by other means, including historical documents as far back as the history goes.

From "Useful Tree Species for Tree-Ring Dating":

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Oak is a highly preferred species to use in dendrochronology - in fact, the longest continuous tree-ring chronology anywhere in the world was developed in Europe and is currently about 10,000 year in length. This chronology is providing scientists new insights on climate over the past 10,000 years, especially at the end of the last Glacial Maximum.

Because ring-porous species almost always begin annual growth with this initial flush, missing rings are rare in such species as oak and elm. In fact, the only recorded instance of a missing ring in oak trees occurred in the year 1816, also known as the Year Without a Summer. A volcanic eruption in the year 1815 caused much cooler temperatures globally, thus causing oak trees to remain dormant. Therefore, no clear annual ring was formed in 1816 for certain locations in Europe.

Occasionally, offsets in oak tree rings can be problematic when trying to crossdate the rings. Dendrochronologists therefore must be careful when working with oak species, as these rays can cause a misdate of one year.

Note that sources of error are identified and accounted for. Crossdating is one method to check for errors. Another is to build two independent chronologies from the same species in two different locations. For an idea of the accuracy of the data and the amount of error involved we have this:

From "INTCAL04 Terrestrial Radiocarbon Age Calibration, 0–26 CAL KYR BP"

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The Holocene part of the 14C calibration is based on several millennia-long tree-ring chronologies, providing an annual, absolute time frame within the possible error of the dendrochronology, which was rigorously tested by internal replication of many overlapping sections. Whenever possible, they were cross-checked with independently established chronologies of adjacent regions. 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 Göttingen and Hohenheim tree-ring laboratories, cross-date back to 9147 cal BP (Spurk et al. 1998).

Due to periodic narrow rings caused by cockchafer beetles, some German oak samples were excluded from IntCal98. Analysis of these tree rings, with an understanding of the response of trees to the cockchafer damage, allowed some of these measurements to be re-instated in the chronology (Friedrich et al., this issue).

The relation between North American and European wood has been studied using bristlecone pine (BCP) and European oak (German oak and Irish oak), respectively. Discrepancies have become evident over the years, in particular when the German oak was corrected by a dendro-shift of 41 yr towards older ages (Kromer et al. 1996). Attempts were made to resolve the discrepancies by remeasuring BCP samples, measured earlier in Tucson (Linick et al. 1986). The University of Arizona Laboratory of Tree-Ring Research provided dendrochronologically dated bristlecone pine samples to Heidelberg (wood from around 4700 and 7600 cal BP), Groningen (around 7500 cal BP), Pretoria (around 4900 cal BP), and Seattle (around 7600 cal BP). The replicate measurements have a mean offset of 37 ± 6 14C yr (n = 21) from the Tucson measurements.

There was not a large difference in the calculated k values between early and recent measurements in the Belfast lab for the Irish oak samples when the previously applied laboratory error multiplier on the more recent data set is considered; however, the early measurements of German oak were more variable than those of Irish oak. The recent Heidelberg data sets had smaller k values than older measurements. The reason for the early variation is partly due to the fact that these samples were measured to help place a tree in the dendrochronology as it was being built instead of measured consecutively, and also because many of these samples contain only a few tree rings but are being compared to decadal samples.

Uncertainty in single-ring cal ages for dendrochronologically-dated wood is on the order of 1 yr for highly replicated and cross-checked chronologies and is therefore ignored in the analysis.

There are several things to note here. First, is that there are three (3) main chronologies: one of Bristlecone Pine and two of European Oak, one German and one Irish. Second, is that originally one oak chronology was "not good enough" to be included in the IntCal98 - because it was off by 41 years in (then) ~8,000 years, an error of 0.5%. Third, is that when one oak chronology was corrected, it was not the odd one out, but the one that previously agreed with the Bristlecone Pine chronology. Fourth, now the Bristlecone Pine chronology is now considered "not good enough" - because it is off by 37 years in ~7600 years, an error of 0.5%. Fifth, that where some German Oak samples had been placed by carbon-14 levels in the earlier chronology (used in IntCal98) these are now placed by additional tree samples that fill in the consecutive chronology (and these initial carbon-14 levels are not now used to place those samples). Finally, that the European Oak absolute chronology now extends back to 9,147 years BP with cross dating and including all three in one data set means that the error involved is on the order of 0.5% - over the whole period of time covered. The IntCal04 discussion doesn't give the breakdown on the actual ages of each chronology, but it refers to a paper that does.

From "The 12,460-Year Hohenheim Oak...d Paleoenvironment Reconstructions":

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The combined oak and pine tree-ring chronologies of Hohenheim University are the backbone of the Holocene radiocarbon calibration for central Europe. Here, we present the revised Holocene oak chronology (HOC) and the Preboreal pine chronology (PPC) with respect to revisions, critical links, and extensions. Since 1998, the HOC has been strengthened by new trees starting at 10,429 BP (8480 BC). Oaks affected by cockchafer have been identified and discarded from the chronology.

These are just three examples of dendrochronologies, the three that happen to be the longest absolute chronologies. There are many species of trees used for dendrochronology, and many different chronologies. Several chronologies are "floating" - do not have a fixed begin date - and many of those are older than the dates discussed here. All the species show the same trends in world climate whenever they overlap. The climatological trends correlate the ages from one species to the others, thus any errors that would invalidate dendrochronology would need to apply to each (and all) species in each (and all) locations at the same time. Here we need only discuss the three long absolute chronologies and how they validate each other.

Now we have a problem for YEC people, because not only do these different chronologies cover the same time, they also have the same pattern of climate shown in their tree rings even though they come from opposite sides of the earth and are in very different kinds of trees, one evergreen living at high altitudes and one deciduous living near sea levels, and anything that can cause errors in one system has to have a method that can cause exactly the same error in the other at exactly the same time. Positing false rings does not accomplish this. All three sets also show the "little ice age" and other marker events at the same ages. They all come to the same age for the matching climate data. We can be minimalist here, and say that the minimum age covered by the European Oak chronology is 10,429 years BP - 0.5% = 10,377 years BP. "BP" means "Before Present" and is defined as years before 1950, so this is really 10,435 years ago (in 2008).


Minimum age of the earth > 10,434 years based on this data.

This is now older than most if not all YEC models for the age of the earth.

And this is still just the start: three different dendrochronologies that correlate age with climate and that match - wiggle for wiggle - within 0.5%.

Enjoy.

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