Dating Techniques have improved in leaps and bounds since the 19thcentury when Charles Lyell first gave stratigraphy widespread publicity as a means of dating archaeological finds, if only relatively. In very simple terms, generally it means that as you dig, older objects will be found under younger ones. For over a century this was one of the few dating methods available to archaeologists, but unfortunately it could not offer specific dates.
Another early dating method was ‘typology’(d), defined as the classification of artefacts according to their physical characteristics.
*This approach can be traced back to the 16th century, when John Leland (1503-1552) began classifying bricks according to size and shape(I).*
Arguably the best known uses of the method relate to Stone Age implements and later to pottery.*Relating to Atlantis studies, we find that Jürgen Spanuth applied typology to the weaponry and dress of the Sea Peoples as portrayed at Medinet Habu to support his theory that they came from Northern Europe.*
Absolute dating began with the introduction of radiometric dating methods beginning with radiocarbon dating developed by Willard Libby in 1949. Around the same time dendrochronology was being refined as a dating method with a margin of error less than that of radiometric methods which require expensive equipment and potentially have a greater risk of contamination. This was followed by thermoluminescence (1957) for dating pottery and more recently optical thermoluminescence (1994) has been developed, enabling the dating of building stone.
Dating objects between 50,000 and 100,000 years old has been difficult as most methods have questionable reliability for this period. However, in 2004 a new method, known as quartz hydration dating was developed at UC Irvine(f).
All the above methods have varying margins of error that are continually being reduced and no doubt will improve further. These enhancements together with new exciting dating methods that can be expected to emerge, will undoubtedly have a profound influence on our understanding of prehistory. Consider how improvements in DNA analysis have enabled the solving of crimes years after cases had gone ‘cold’.
More cautionary offerings(a)(c) came from the catastrophist website, thunderbolts.info., in which events involving influences outside our planet might affect the assumptions upon which some of our radiometrics are based. Since these events are not frequent occurrences we do not, as yet, have enough data to develop reliable calibration charts.
In May 2012, the journal Nature, Ewen Callaway has an article(b) which further highlights potential weaknesses that may be encountered with radiocarbon dating.
The fascinating CAIS website offers a good overview(e) of the range of sophisticated dating techniques available today. We can reasonably expect it to expand.
A July 2015 article(g) in the Proceedings of the National Academy of Sciences. has highlighted a new threat that the burning of fossil fuels has introduced into the reliability of radiocarbon dating.
“As carbon-14 decays over time the fraction will decrease so that’s how we use it for dating,” the paper’s author Dr Heather Graven told BBC News.
“But we can also change this ratio of radioactive carbon to total carbon, if we are adding non-radioactive carbon and that’s what’s happening with fossil fuels, we get this dilution effect.”
“At current rates of emissions increase”, according to the research, “a new piece of clothing in 2050 would have the same carbon date as a robe worn by William the Conqueror 1,000 years earlier.”
The latest dating method, proposed by Michael Dee and Benjamin Pope(h) combines dendrochronology with radiocarbon dating and is designed to identify specific years based on spikes in the carbon14 found in specific growth rings, caused by energy discharges during solar storms. Dee and Pope have called this new science astrochronology and anticipate that its application will tie down the so-called ‘floating chronologies’ of ancient Egypt and elsewhere.