Dendrochronology has [somehow] managed to transform the subjective art of tree ring aggregation and pattern matching into a Settled Science that’s used to bridge chronology gaps.
Bridging is simply based upon finding a Sample or Site Master or Chronology that crossmatches the two sides of the problematical gap.
Whether the Bridging is valid [or inappropriate or tenuous or bogus] depends upon the knowledge and integrity of the dendrochronologists involved.
This is a particular issue when the Bridging crossmatches different species or diverse geographic areas which are otherwise unconnected.
These bridging skills have enabled dendrochronology to assemble long chronologies that encapsulate thousands of tree ring samples from disparate sources.
Compilation of the central European Holocene oak chronologies of the Hohenheim laboratory.
The blocks represent replicated regional chronologies which were linked dendrochronologically to each other.
The chronology from the river Main consists of an unbroken record from 8239 BC to AD 1100.
The chronology of oaks from archaeological sites, historical timbers, and living trees connect the prehistoric chronologies to the present.
The numbers at the left-hand end of the bars give the calendar year (cal BC) of the oldest oak tree ring in the respective region.
The 12,460-year Hohenheim Oak and Pine Tree-Ring Chronology
Michael Friedrich, Sabine Remmele, Bernd Kromer, Jutta Hofmann, Marco Spurk, Klaus Felix Kaiser, Christian Orcel, Manfred Küppers
Radiocarbon, Vol 46, Nr 3, 2004, p 1111–1122 – 2004
Unfortunately, whether by accident or design, these bridging techniques will inevitably include some false positives that create misleading virtual reality chronologies where bridging components have been reversed and/or replicated.
In 1976 Leona Libby dramatically demonstrated to the dendrochronologists that the only way to avoid the false positives associated with bridging is to use single tree chronologies.
More importantly, Leona Libby demonstrated that the reliability of their bridging technique could be significantly enhanced by incorporating isotopic ratio matching.
Libby showed that the atmospheric ratio of stable hydrogen and oxygen isotopes is preserved in tree-rings and demonstrated that this isotopic ratio is determined by atmospheric temperatures [at the time of formation].
Evidently, this was a scientific step-too-far for academia because they prefer the Settled Science of the Carbon-14 calibration process that protects their cherished “known” dates.
Calibration is needed because the atmospheric 14C/12C ratio, which is a key element in calculating radiocarbon ages, has not been constant historically.
Although Willard Libby, the inventor of radiocarbon dating, had pointed out as early as 1955 the possibility that the 14C/12C ratio might have varied over time, it was not until discrepancies began to accumulate between measured ages and known historical dates for artefacts that it became clear that a correction would need to be applied to radiocarbon ages to obtain calendar dates.
Ironically, there is no escape for academia because the Carbon-14 values embedded within their consensus calibration curve provides an auditing mechanism.
► Decay Curve Flipped Flipped Horizontally
► Anthropogenic C14 Time Travel
► 0 – 712 CE Replication Artefact
► Maunder Minimum
► Pivot Point 465 BCE
More significantly, the Carbon-14 values embedded within the consensus calibration curve provides an mechanism for identifying reversed and/or replicated artefacts in the chronology.
The beginning of the flipped decay curve around 800 BCE and the ending of the replication artefact around 700 CE suggests there is [roughly] a period of 1,500 years that contains reversed and replicated elements embedded within the consensus calibration curve.
This would explain why the calibration process needs to apply different adjustment techniques to the BC and AD periods.
Reviewing the Carbon-14 gradients and inflection points currently embedded within the consensus calibration curve [between 800 BCE and 700CE] suggests it may well contain a long established virtual reality period of [about] 1,500 years that is composed of
reversed and replicated elements from other parts of the chronology.
Personally, I think dendrochronologists would be well advised to concentrate on single tree chronologies.