Looking at this comparatively new field of study, first we need to understand the concept of archaeology. It is such a varied concept that it is an anthropological, historical and scientific study because it is a study of mankind looking at its history with the help of modern scientific methods.
Modern archaeology developed as a discipline from the 19th c. although most of the ancient civilizations were discovered much before this, e.g. Egyptian civilization was known during Napoleon’s military expeditions (1798-1800). Major breakthrough came in this field after World War II as it started getting scientific aid and conceptually with Binford’s argument that its potential is much more than counterfeit history. Today most of the countries have their own government archaeological departments. Until the previous century archaeologists had an historical approach, also known as processual archaeology, but modernist thinkers emphasize on postprocessual archaeology which focuses on varied perspectives of different social groups.
Now we shall look at the goals of an archaeologist and the means to achieve it. The goals of postprocessual archaeologists, according to Sharer and Ashmore, should be to: (1) consider the form of archaeological evidence and its distribution in time and space; (2) determine past function and thereby construct models of ancient behaviour; (3) delimit the processes of culture and determine how and why cultures change; (4) understand cultural meaning through symbols, value and worldview. In order to achieve these goals, the most important thing for any archaeologist is evidence, so one should clearly identify the context of various kinds of evidences (viz. artefacts, ecofacts and features), i. e. immediate matrix, its provenience and its association with other finds.
For the purpose of obtaining evidences an archaeologists has to go through a long process of which sampling is the first step. After preparing the research design, one needs to take a sample because it is not possible to dig the whole site. Sampling are of two types non-probabilistic sampling where primary emphasis is on presence or absence of material, and probabilistic sampling which is based on the theory that the samples collected are related in mathematical terms to the population sampled. Probabilistic sampling is further categorized as cluster sampling, nested sampling, simple random sampling, systematic random sampling, systematic unaligned sampling, and stratified random sampling. Now it is upon the archaeologists to select the best method and also fraction and size of sample.
The second step is ‘Site Survey’ which is to illuminate a landscape signature and detecting and comprehending a settlement pattern. In the process of surveying, one needs to discover and identify sites. The factors in survey design include visibility (the extent to which an observer can detect the presence of archaeological materials), obtrusiveness (cultural visibility of the materials produced by society) and accessibility (effort required to reach a particular survey area). One must prepare the background for research with the help of literature, local informants, history and ethnohistory, and environmental variables. Further, field methods in site survey are pedestrian survey, which is simply surveying by walking through the site, subsurface survey, which is digging holes in low visibility area, test-pitting, which is considered as the most effective methods by most of the archaeologists, and chemical survey, which is used to study soil anomalies. Remote sensing is carried out for detection of evidence without digging soil. There are certain instrument anomaly surveys techniques like CAT scan, magnetic survey using proton magnetometer, electrical resistivity surveying where a current is passed through the soil, ground penetrating radar is an instrument which releases an electromagnetic pulse into the ground and its reflection time is dependent upon the density and distance of whatever the pulse encounters. Aerial survey is also done for the same purpose by doing aerial photography and infrared photograph. At last mapping of surveyed site is necessary. A significant new development in the field of mapping is made with the use of GIS (Geographic Information System). Aerial photography is useful even for mapping.
Archaeological field photography is a technical work which we shall see in brief. Its basic purpose is photo documentation which is to produce a comprehensive and precise pictorial record of an investigation, and photo illustration which is to provide images appropriate for use in public presentations. Some basic elements of photography include film speed, diaphragm opening, exposure time, light intensity and relationship between them. The matters to be photographed are general site views, features and burials, excavation processes, soil profiles, artefacts etc.
After completing site survey, the next step is ‘excavation’. First, we must make note of the tools required for this purpose: large tools are like vehicles, chainsaw, shovels etc. and hand tool like pointing trowel, margin trowel, line level, plump bob, whisk broom, ice pick, brunton compass, measuring tape, folding wood rule, marking pen, paint brushes, sledge hammer, magnifying glass, hand sprayer, plastic sheets, tags and personal safety equipment. Some of the excavating techniques are step trenching where a large area opened at the top which gradually narrows as the dig descends in a series of large steps, strip method where digging begins at the edge of the area to be excavated, quartering where the mound is laid out into four quadrants and each quadrant is excavated systematically, architectural unit excavation where an architectural unit (viz. house, room or pit house) are used as excavation unit, area excavation, i.e. orderly exploration of a sizable expanse of a site, and stripping which is used to remove large areas of overburden to expose stable land surface bearing cultural features (viz. living floors, houses etc.). Now let’s look at methods, which are vertical face method where a unit is dug entirely as a single vertical face, unit level method where the technique is to dig each pit, defined by the lines of the gird system, and natural stratigraphic level method which involves peeling of the visible strata in a site deposit. After excavation is done, one needs to screen the excavated deposits, which enables archaeologists to recover many objects that might otherwise be overlooked, and then they are washed with gasoline. Apart from these above mentioned methods, different techniques are required for special sites, e.g. water saturated sites, caves, rock shelters etc. After the work is done, the holes should be back filled.
For record keeping of the evidences archaeologists require to mark their vertical and horizontal location, classify them on the basis of their attributes, viz. surface, shape and technology; noting stratigraphic position etc. All these records have to be maintained in a tag attached to these evidences. Maintaining of records in a computer makes the procedure comparatively easy. Further, for the protection of certain objects made of lithic, ceramic etc. needs special care, and rock art can be easily maintained pictographs and petroglyphs.
After the field work is over, laboratory work begins of which the first step is ‘dating’ of evidences. The two basic problems of dating are security of context and contamination of sample with more recent materials. Different dating methods are used for different materials which is to be dated, e.g. for biological dating DNA are studied, for calculating a tree’s age tree ring dating is done. Apart from this some of the common dating methods fall under two categories, namely radioactive methods and trapped electron dating methods. Under radioactive methods, the most popular is radiocarbon dating in which decay of carbon atoms are calculated as it is known that half life of C-14 is 5730 years. Its greatest advantage is that it can be used anywhere and also radiocarbon dating along with AMS is opening up new possibilities. The other techniques under this category are potassium-argon dating which is mainly used for dating of rocks, uranium series dating which is useful for dating of objects that are 5,00,000 to 50,000 years old, and fission –track dating. Techniques under the second category are thermo-luminescence dating. It is possible to empty electron traps by the application of heat, so this technique is used for fired materials, viz. pottery, ceramics etc. The other techniques under this category are optical dating which is used for dating of minerals that have been exposed to light for a long time, and electron spin resonance dating which is useful for materials that decompose when heated. The other dating methods are obsidian hydration, amino-acid racemization, chlorine-36 dating, archeomagnatic dating etc. Further, dating of the climate is also necessary, e.g. dating of Pleistocene epoch has been very popular since the 19th century. For this purpose deep-sea cores and ice cores are studied. These layers contain remains micro-organisms which when tested reveal their ages. Another method is pollen dating where with the help of pollen grains, experts construct detailed sequences of past vegetation and climate. Last in this is faunal dating where animal remains are studied for this purpose.
The other laboratory works include ‘stratigraphy’ which is the study of the layers. The major principle in archaeological stratigraphy is the law of super position. Its main goal is to work out the sequence of deposits and elicit the events producing them. Creating ‘typological sequence’ which is supposed to be done by studying the changes. One step of this is seriation which is exercised in relative chronology. This is further divided into contextual seriation where the duration of different artefact styles, and frequency seriation where frequency of objects is measured. After performing the entire above mentioned laboratory works, the results are matched with the historical records. Earlier only historical methods were used for dating now, archaeologists are able to give accurate chronology by matching the two.
Another important work for the archaeologists is to identify the physical characteristics of human being which include their sex (mostly done by examination of genitalia, breasts, beards etc.), interpreting age at the time of death, height & weight, their looks, walking posture (study of their foot prints is important for this), use of hands, development of speech, sexual behaviour, eating habits etc. All these things are known by detailed scientific analysis of human skeletal and dental remains.
After obtaining the evidences and studying them scientifically, archaeologists and historians use them for reconstructing social, economical and environmental history. Regarding social history, the first question is regarding scale of the society and next is internal organization. An American anthropologist Elman Service developed a four-fold classification of societies, namely bands of hunter-gatherer whose sites mainly consist of seasonally occupied camps, segmentary societies (tribes) where agglomerate structures are found, chiefdoms(their graves consist of rich good which is considered as the grave of the chief) and early states which show urban patterns. Scholars are able to make out the above mentioned considerations by studying the number of human remains, settlement patterns, and further information are gathered from written records, oral traditions and ethnoarchaeology. Further, there are specific methods for various sites.
In order to understand the economic history one needs to study interactions among societies and exchange relations between them. Here exchange refers not only to the exchange of goods but also of ideas. Early indications of exchange came from artefacts of different origin found from other sites. Apart from this there are other methods, viz. the study of distribution, production, consumption, exchange and symbolic representations. Greater understanding of trade networks come from studies of production in areas like mines and quarries.
For understanding of environmental archaeology one needs to study the whole ecosystem on a global scale. Evidences for this comes from cores from sea and ice, isotopes are useful for studying temperatures and winds, glaciated landscapes, varves, rivers, sediments, soils and other environmental factors.
At last, there are certain archaeological ethics which every archaeologist and historians should follow. One must note that the archaeological properties are communally owned so it should be placed in a museum, although there could be a conflict for private ownership. The work done should always be beneficial for the people, i.e. use of the past should be done in a positive way that we learn a lesson from them, e.g. we must learn the art of town planning from Harrapan people.