Cation ratio dating

This ratio is called the Oxidizable Carbon Ratio, or OCR.' (Douglas S.Frink) 'Because interpretation is so complex, all radiocarbon dates included in an archaeological publication must be presented in a standard manner. Archaeologists must know exactly what is being dated and, in the case of samples from excavations, their precise stratigraphic relationship to the site.107) Note: for the latest authoritative book on scientific dating see: R. 112) 'Pollen that has accumulated in deep deposits such as peat-bogs supplies a sequential record of changes in vegetation since the last Ice Age, for variations in temperature and rainfall resulted in periods of markedly different plant and tree populations in the past. Since climatic zones established from pollen have been dated absolutely by radiocarbon, they are no longer required as chronological indicators; nevertheless, pollen analysis continues to supply important evidence for the interpretation of the ancient environment.' (p.112-13) Palynology Page University of Arizona: 'PALYNOLOGY is the branch of science dealing with microscopic, decay-resistant remains of certain plants and animals.The speed of decay is expressed as the half-life, the time taken for half of the total radioactivity to decay; this may vary from seconds to millions of years.' (p.114) 'The rate of decay of carbon-14, which has a half-life of 5730 years, is long enough to allow samples of carbon as old as 70,000 years to contain detectable levels of radioactive emissions, but short enough for samples from periods since the late Stone Age to be measured with reasonable precision.113) 'Each winter's snowfall creates a distinct layer, and the annual layers have been counted back almost 6000 years in a core more than two kilometres in depth, with an excellent level of reliability within around 50 years...

104) NEW - Roman military sites in Britain 'A non-specialist's introduction to the fortresses, forts, watchtowers, temporary camps, depots and industrial sites, built by the Roman Army in Britain.' (Peter Green). There is also a comprehensive and detailed review: 'Nineteenth-century geologists were preoccupied with the age of the Earth, and Darwin's demand for gradual evolution underlined the length of the time-scales involved.offered the possibility that a similar, generally applicable, technique might one day be found that would give absolute dates for prehistoric archaeology.' (p.114) 'Several scientific dating techniques exploit the phenomenon of radioactive decay, including those first used to date the age of the Earth in the early years of the twentieth century.Many elements occur in different forms, and some are unstable; these isotopes have extra neutrons besides their standard number of protons and they are designated by a number representing their atomic weight (carbon-14 or 14C).Unstable isotopes are radioactive and emit rays of particles at a known rate.

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