Archaeology (Greek: ἀρχα ος, "ancient"; and λόγος, "study") is the science that studies human cultures and civilizations of the past and their relations with the surrounding environment, via the collection, documentation, and analysis of the material they have left behind, such as architecture, artifacts, biological and human remains. Within the various universities of United States of America archaeology, along with ethnology, linguistics and physical anthropology, is considered a sub-field of anthropology, the scientific study of human life and cultures from earliest times to the present day.
Archaeology is traditionally divided into disciplines according to the period or culture being studied (i.e. classical archaeology, Egyptology, industrial archaeology, etc.); particular investigative techniques (underwater archaeology, experimental archaeology, etc.); specific problems (urban archeology, theoretical archaeology, etc.); or based on the type of material examined (numismatics, epigraphy). The notion of archaeological discovery has evolved as research methods progressed, with discoveries becoming less and less dependent on chance or intuition.
Archaeological research methods are divided into those of source indexing and those of interpretation. In the public eye, usually only the development of the sources is noted, which also includes the typological and chronological evaluation. Historical interpretations are made when the source development and preparation is done.
The survey is that which the archaeologist and his team does to determine whether or not the site is valid for excavation; it is non-destructive in nature, and makes use of historical written documents and/or non-destructive methods and tools that enable the investigation of potential or known sites. Such methods and tools include aerial photography (as from an aircraft, balloon, or drone), remote sensing, and geophysical methods (geoelectrics, electromagnetic induction, geomagnetic mapping, ground-penetrating radar and LIDAR).
The second step in the survey is a preliminary excavation in which a small area of the potential site is disturbed. This excavation uses search trenches, magnetic sounding, soil resistance measurement, phosphate testing and other methods of soil research. This excavation and further related research serves to form a picture of the potential excavation site in order to better plan the actual excavation.
The excavation of the potential site takes place after a thorough survey is completed. A rope-grid is mapped out and pegged on the site, usually consisting of an area divided into several square yards or meters, and further divided into individual squares. Test pits are then dug, which are used to determine the density, spread, and location of artifacts. Satisfied with the results, the main excavation then begins with a larger dig within the grid. Overlaying soil is carefully removed, exposing any artifacts which may lie beneath. The artifact itself is not initially removed at first; it is carefully mapped in relation to the site and photographed. Since archaeology itself is destructive in nature, careful documentation of all finds is extremely important, and reconstructable in detail later on. In addition, soil which has been removed is carefully sifted via a mesh screen for small artifacts which may have been missed.
Although the actual excavation is the best-known research method, it is only a small part of the archaeological work. The documentation, evaluation, conservation and archiving of the finds represents by far the largest part of the archaeological activity, and is done using the following methods and tools:
Typology is the classification of objects according to criteria of form and material. It is fundamental for the classification of artifacts, since it allows comparisons with artifacts found at other sites and becomes the basis of combination analyses (for the relatively chronological dating as well as the socioeconomic classification) and distribution analyses.
As with the survey and age determination, modern scientific techniques are also used for material determinations (such as Archaeometry). For the identification and detailed investigation of artifacts a number of tools are used, such as microscopy, infrared and ultrasound imaging, X-ray, chemical and spectral analysis and laser scanning.
Determination of age
A focus of archaeological analysis is the dating of the site (such as a grave) on the basis of the artifacts found (i.e. grave goods). The dating of the site distinguishes between absolute chronology and relative chronology.
Relative, or indirect chronology relates the comparative analysis of one find to another, or in the context of associated regional, cultural, or geological evidence:
In absolute chronology an artifact or site is assigned an absolute date:
- Carbon-14 dating (for organic substances)
- Thermoluminescence dating also: TL dating (for ceramics)
- Dendrochronology (for wood)
- Potassium-argon method (for rock)