Advantages and disadvantages of relative dating
A common procedure for estimating ages in a set of samples from a stratigraphic core is to assign, based on complementary data, the ages at a number of depths (tie points) and then assume a uniform accumulation rate between the tie points.Imprecisely dated or misidentified tie points and naturally varying accumulation rates give rise to discrepancies between the inferred and the actual ages of a sample.We provide a method by which error estimates like these can be made for similar stratigraphic dating problems and apply our statistical model to an idealized marine sedimentary paleomagnetic record. Both types of errors severely degrade the spectral content of the inferred record. For a variable accumulation rate, we require the actual ages of a sequence of samples to be monotonically increasing and the age errors to have the form of a Brownian bridge. The actual ages are modeled by integrating a piecewise constant, randomly varying accumulation rate.In each case, our analysis yields closed form expressions for the expected value and variance of resulting errors in age at any depth in the core.By Monte Carlo simulation with plausible parameters, we find that age errors across a paleomagnetic record due to misdated tie points are likely of the same order as the tie point discrepancies.
This is because I am reviewing the volume, in the main, for scholars in the humanities disciplines rather than for scientists; therefore I shall attempt to interest and inform both audiences.
Nonetheless, chronology--the science of measuring time in fixed periods and of dating events and epochs and arranging them in their order of occurrence (e.g., the sequential ordering of events or the tabulations derived from this activity)--is a fundamental component of scientific and humanistic inquiry.
Basic textbooks on archaeological method and theory relate that there are two methods of establishing chronology: 1) methods of relative dating (ascertaining the correct order of the events) and 2) absolute or chronometric dating (quantifying the measurement of time in terms of years or other fixed units).
This impressive and well-written volume focuses exclusively upon absolute or chronometric dating techniques and presents an up-to-date wealth of information about methodologies in a dynamic field. Taylor and Aitken, both of whom are established scientists and scholars, are also the editors of the volume being reviewed. His research focuses on the application of dating and analytical techniques in archaeology (the latter known as archaeometry) with an emphasis on radiocarbon dating. Kra of Radiocarbon after Four Decades: An Interdisciplinary Perspective (1992). Aitkin is now Emeritus Professor of Archaeology at Oxford University and was for many years affiliated with Oxford's Research Laboratory for Archaeology and the History of Art.
This is both a compelling and an essential reference for those scholars who wish to understand current procedures and problems, and future prospects in science-based archaeological chronology. The volumes in this series are published in cooperation with the Society for Archaeological Sciences (SAS), an organization of natural scientists and professional archaeologists. Taylor is the author of numerous scientific papers and monographs, including (1987) and was coeditor with A. Holding a doctoral degree in nuclear physics, his principle areas of research were in magnetic prospection, archaeomagnetism, and luminescence dating.
The editors recognize that because of the increasing complexity of many of the dating techniques, it is no longer possible for one or even a few authors to assemble and assess adequately the ever-increasing literature and the current directions of research for more than one or two of the techniques.