Stratigraphy harris matrices relative dating of australian rock art
The process of excavation destroys the context and requires the excavator to be able and willing to make informed (by experience and where necessary collaboration) decisions about which context(s) lay at the top of the sequence.
As long as undercutting is not endemic, in practice onsite errors in judgment should become evident especially if temporary sections are kept for stratigraphic control in areas of a site that are hard to discern.
Also note the matrix splits into two parts below the construction cut 5, this is because the relationships across the section have been destroyed by the cutting of construction cut 5 and even if it is likely that layers 1 and 4 are probably the same deposit the information can not be guaranteed if the only information we had was this section.
However the position of cut 5 and natural layer 11 "ties" the matrix together above and below the split in the matrix.
The Harris matrix is a tool used to depict the temporal succession of archaeological contexts and thus the sequence of depositions and surfaces on a 'dry land' archaeological site, otherwise called a 'stratigraphic sequence', the matrix reflects the relative position and stratigraphic contacts of observable stratigraphic units, or contexts. The concept of creating seriation diagrams of archaeological strata based on the physical relationship between strata had had some currency in Winchester and other urban centres in England prior to Harris's formalisation.
The Matrix was developed in 1973 in Winchester, England, by Dr. One of the results of Harris's work, however, was the realisation that sites had to be excavated stratigraphically, in the reverse order to that in which they were created, without the use of arbitrary measures of stratification such as spits or planums; in his Principles of archaeological stratigraphy Harris first proposed the need for each unit of stratification to have its own graphic representation, usually in the form of a measured plan.
In a series of layers and interfacial features, as originally created, the upper units of stratification are younger and the lower are older, for each must have been deposited on, or created by the removal of, a pre-existing mass of archaeological stratification.
Any archaeological layer deposited in an unconsolidated form will tend towards a horizontal disposition.
The later a context's formation is, the higher it is in the matrix, and conversely the earlier it is, the lower.Several other people, such as Norman Hammond, looked to develop similar systems in the 1980s and 1990s.The dating of South African rock art using radiocarbon is a considerable challenge and only 1 direct date has so far been obtained, on black pigments from Sonia's Cave Upper, Boontjieskloof.This diagram, which is based on the Harris matrix, is designed to represent the time lapse in use of recognizable archaeological entities such as floors and pits.Like Edward Harris, he used contexts numbered and defined on site as the basic elements of the sequence, but he added higher order groupings ("feature" and "structure") to increase the interpretive power.