Pre dating wood
Radiocarbon Dating Founded on a false belief that levels of carbon isotopes never vary, initial radiocarbon dates were commonly off by hundreds of years.
Because wood can be dated directly and by radiocarbon, scientists used bristlecone pines to calculate a new calibration curve, and convert radiocarbon results into accurate calendar dates.
However, such is the rapid decay of radiocarbon (C), with a half-life of 5,730 years, that even after only 250,000 years there should be no detectable radiocarbon left.
Thus, organic materials supposedly millions of years old should not contain any radiocarbon whatsoever.
Once the timeline exists, the age of similar wood (e.g., from a nearby house) can be established by pattern-matching.
Meticulous laboratory procedures rule out the possibility that this measured radiocarbon is due to contamination, so it must instead be intrinsic to these ancient organic materials.
Pyrolysis-GC/MS and optical microscopy techniques were applied to material from the human cranium, a weaving tool, and a small bowl.
These techniques, as well as routinely applied laboratory quality assurance procedures, indicated that there was no residual pitch within the cranium or the weaving tool after pretreatment, giving confidence to the dates.
Dendrochronology, or tree-ring dating, provides absolute dates in two different ways: directly, and by calibrating radiocarbon results.
Direct Dating of Wood Cross-dating determines the age of undated wood by directly matching ring patterns with trees of known age.