Dating Techniques In Archaeology
May 18, Relative dating is used to arrange geological events, and the rocks they The method of reading the order is called stratigraphy (layers of rock. Mar 7, Absolute dating, methods that produce specific chronological dates for objects Stratigraphy is the oldest of the relative dating methods that. Jan 23, There are two main categories of dating methods in archaeology: indirect or Absolute dating methods mainly include radiocarbon dating.
A horizontal layer Backfill of the wall construction trench sometimes called construction cut A horizontal layer, probably the same as 1 Construction cut for wall 2 A clay floor abutting wall 2 Fill of shallow cut 8 Shallow pit cut A horizontal layer, probably the same as 9 Natural sterile ground formed before human occupation of the site Trample in the base of cut 5 formed by workmen's boots constructing the structure wall 2 and floor 6 is associated with.
If we know the date of context 1 and context 9 we can deduce that context 7, the backfilling of pit 8, occurred sometime after the date for 9 but before the date for 1, and if we recover an assemblage of artifacts from context 7 that occur nowhere else in the sequence, we have isolated them with a reasonable degree of certainty to a discrete range of time. In this instance we can now use the date we have for finds in context 7 to date other sites and sequences.
In practice a huge amount of cross referencing with other recorded sequences is required to produce dating series from stratigraphic relationships such as the work in seriation.
Residual and intrusive finds[ edit ] One issue in using stratigraphic relationships is that the date of artifacts in a context does not represent the date of the context, but just the earliest date the context could be.
Dating in Archaeology | The Canadian Encyclopedia
If one looks at the sequence in fig A, one may find that the cut for the construction of wall 2, context 5, has cut through layers 9 and 10, and in doing so has introduced the possibility that artifacts from layers 9 and 10 may be redeposited higher up the sequence in the context representing the backfill of the construction cut, context 3.
These artifacts are referred to as "residual" or "residual finds".Relative and Absolute Dating
It is crucial that dating a context is based on the latest dating evidence drawn from the context. We can also see that if the fill of cut 5 — the wall 2, backfill 3 and trample 12 — are not removed entirely during excavation because of " undercutting ", non-residual artifacts from these later "higher" contexts 2, 3 and 12 could contaminate the excavation of earlier contexts such as 9 and 10 and give false dating information. These artifacts may be termed intrusive finds.
When combined with stratification analysis, an analysis of the stylistic changes in objects found at a site can provide a basis for recognizing sequences in stratigraphic layers. Archaeological stratigraphy, which focuses on layers created by man, was derived largely from the observations of stratigraphic geologists and geomorphologists.
A geomorphologist studies stratigraphy in order to determine the natural processes, such as floods, that altered and formed local terrain. By comparing natural strata and man-made strata, archaeologists are often able to determine a depositional history, or stratigraphic sequence—a chronological order of various layers, interfaces, and stratigraphic disturbances.
By this method, archaeologists can illustrate the strati-graphic sequence of a given site with a single diagram. Such a diagram, showing the different layers with the oldest at the bottom and the youngest at the top, may cover 3, years. The diagram also records finds such as pits, post holes, and burials that may have belonged to a single period.
The archaeologist may also document the site with notes about the relationships of stratigraphic units and soil composition. History of stratigraphy The basic principles of stratigraphy were developed primarily by geologists in the nineteenth century. Among the first archaeologists to understand the stratigraphy of tells artificial mounds were William Matthew Flinders Petrie at Tell-el-Hesi inHeinrich Schliemann at Troy between andand R.
Pumpelly and Hubert Schmidt at Anau in Another major force behind the acceptance of archaeological stratigraphy was General Pitt-Rivers —who considered that material culture could be explained in terms of a typological sequence—objects that had evolved over time.
In his excavations, he practiced the total excavation of sites, emphasizing the principles of stratigraphy. Giuseppe Fiorelli, who assumed responsibility for the excavation of Pompeii inalso pioneered the use of stratigraphic methods in archaeology. Some early advocates of the principles of stratigraphy found opposition from many of the same traditionalists who opposed the theory of evolution.
Relative dating methods determine whether one sample is older or younger than another. They do not provide an age in years. Before the advent of absolute dating methods, nearly all dating was relative. The main relative dating method is stratigraphy. Absolute dating is the term used to describe any dating technique that tells how old a specimen is in years. These are generally analytical methods, and are carried out in a laboratory.
Dating in Archaeology
Absolute dates are also relative dates, in that they tell which specimens are older or younger than others. Absolute dates must agree with dates from other relative methods in order to be valid. As previously mentioned, radioactive decay refers to the process in which a radioactive form of an element is converted into a nonradioactive product at a regular rate.
Radioactive decay dating is not a single method of absolute dating but instead a group of related methods for absolute dating of samples.
Additional Topics Dating Techniques - Seriation Seriation is the ordering of objects according to their age.