In archaeology, exploration and excavation works play an important role. Exploration is the act of searching, for the purpose of discovery of information or resources. Archaeologists first explore new sites with the help of sources and modern technology like aerial photography, chemical analysis of soils, etc and then excavation work started.
So, the location of artefacts is generally done by identifying sites and collecting them from the surface of such sites and unearthing them by conducting excavations. In this process of exploration and selection of sites, earlier they were selected on the basis of oral traditions, mythological references, finds of certain items on the surface due to soil erosion or shapes of the mounds, etc. Now a days, many scientific methods are employed which provide some proof or indication of human habitation in the past. Some of these are as follows:-
1. Aerial photography which records the slightest change in the level of the ground surface. It also records differences in the colouring of the soil (i.e. soil markers) or the development vegetation (i.e crop markers), which are often due to buried Archaeological remains. This methods is more effective in open landscape and not in forested area.
2. Underwater prospection to detect wrecks of ships or submerged sites. Highly sophisticated equipments have been developed for this purpose (underwater television camera, bathyscaphes, etc.)
3. Magnetic detection of metal objects like ovens, hearths, field-in pits and wells, foundations, tombs and so on by means of equipment such as proton or caesium magnetometers, proton gradiometers, etc.
4. Detection of electrical anomalies in the subsoil caused by the presence of foundations (which reduce conductivity) or filled-in pits (which increase conductivity) by means of potentiometers designed to measure the resistivity of the subsoil.
5. Prospection by acoustic or seismic methods using instruments that register vibratory phenomena obtained by reflection, refraction or resonance following the sounding of the site or variable-frequency Hertzian wave transmission.
6. Chemical analysis of soils, especially the measurement of phosphate and potassium contents, makes it possible to detect soils on which humanity has left its mark (former dwelling sites).
With some other methods, even if modern techniques are followed it is mainly indicative and archaelogists have to make a physical inspection of the site to take a decision about excavation. Most of the sites are noticed accidentally through diggings for building construction, laying or roads or railway lines or cultivating land. For example, Harappan Civilization came to light when the contractors laying a railway line nearby decided to procure bricks from the mound and exposed it. After that, subsequent excavations revealed the earliest civilization of the subcontinent.
Excavation is the exposure, processing and recording of archaeological remains. Excavation involves the recovery of several types of data from a sites. This data includes artifacts, burials, ruined cities, bones, etc.
There is always a possibility of finding artefacts from various layers of the same site. This generally happens when the same site is used and inhabited repeatedly by the succeeding generations. In such a situation as one goes deeper into digging one goes back in time. Many a times material remains may not be neatly available in different layers and their might be overlapping and mix-up of the available artefacts in different layers.
Excavation can be vertically or horizontally. Vertical excavation means lengthwise digging to uncover the period-wise sequence of cultures; it is generally confined to a part of the site. While horizontal excavation entails the excavator to obtain a complete idea of the site culture in a particular period. As most sites have been dug vertically, they provide a good chronological sequence of material culture. Horizontal diggings are very expensive. Excavations conducted at various sites in the valley of Indus River, Lothal in Gujarat, Kalibangan in Rajasthan give us knowledge of the civilization during c. 2700 B.C.
Next Article:
1. Excavation works, Ruined cities and other archaeology artefacts
2. Literary Sources
3. Archaeological Dating Methods
References:
Also see:
1. Coins
4. Literary Sources
5. Primary, Secondary and Tertiary Sources
6. Bharatvarsha
7. UGC NET JRF Latest Syllabus
8. Inscriptions
