Gulf of Cambay Cradle of Ancient Civilization (cont.)
By Badrinaryan Badrinaryan
Even though most of the artifacts are of Mesolithic period, there were some Paleolithic tools which were much older. It shows that people have been living in the Cambay area for quite some time. One example is the bifacial scrapper, made of chert and a very characteristic upper Paleolithic stone tool (Fig.36). Similar stone tools were also present but many of them due to long submergence and rolling in the seabed appear to have their edges smoothened out and the sharpness of the edges is rather less.
Figure – 34
A thorough examination of the macro and micro levels of soils in Gulf of Cambay brought to light a wealth of plant material typical of the land domain. Extensive studies are being carried out by a Botany Professor and the studies may initiate a new branch in Marine Archaeology which may be called as Marine Archaeo Botony. So far prominent plant species identified include palm, coconut, bamboo, areca plant, etc. Many of them are fossilized. Some of the species identified and photographed are as follows (Fig.35). The top left show fossilized food grains, in top right one could observe the inner portion of a bamboo plant. In the bottom left, plant fiber material could be clearly seen and at bottom right one could see palm leaf with typical ridges. All these were recognized under the microscope.The major wooden log a part of which is shown in Fig.18, when taken out of the seabed was very fresh, dark, hard and showing growth rings, etc. Within a couple of days of exposure to the atmosphere the wooden log completely shrunk and developed cracks. It has given important date for the area. This species has been tentatively identified as belonging to hard wood like rosewood. All these point to well grown trees and foliage with lot of good fresh water and somewhat warm climate, at the time of their growth in the area.
Bi-Facial Scraper-Upper Palaeolithic
Figure – 36
The palaeo channel below the alluvium has hard dark alluvium and then typical river conglomerate (Fig.34). It clearly indicated fresh waters alluvial environment. Several insitu pieces of alluvium and conglomorate have been collected. All these factors clearly establish that the palaeochannels were originally well-flowing rivers in the land, which were subsequently submerged by the sea.
Since some persons have expressed doubts about the pottery pieces, a thorough scientific study was made involving the pottery pieces to establish their authenticity. To determine the properties of various material including pottery, many samples were subjected to X-Ray diffraction (XRD) analysis. Since the materials that constitute pottery etc are clays and heterogeneous mixures of a variety of materials, these were accordingly analysed. Every area has a special fingerprint pattern in the clay which can be recognized in X-Ray diffraction (XRD). The above analysis was carried out in Deccan College, Pune Maharashtra state, India,by using an advanced instrument which gave excellent results. The conclusions are that the pattern of pottery pieces corresponds very well with the locally available clay of gulf of Cambay. The mineral patterns of habitational floor, wattle and daub and land materials (alluvial deposit) are comparable. The patterns of fired clay, floor birck piece, vitrified clay, compare very well. All these indicate that they are genuine artifacts, made from locally available material and are insitu. It fully confirms the presence of archaeological sites. The findings indicate that the pottery was produced locally with levigated clay, fired uniformly at about 700oC. From the presence of calcite in clays and pottery arid to semi-arid environmental conditions prior to the submergence of the site could be deduced. Calcritised alluvial deposits indicate the existence of ancient rivers which once flowed in the submerged regions of Gulf of Cambay.
Figure – 35
Dating of samples : Most of the structures that were discovered in the Gulf of Cambay had many similarities to the CITADEL, GREAT BATH and grid-iron pattern habitation sites grannery, etc. of the Harappan civilization. But many of the artifacts and typology were very different and distinctive and with the presence of so many micro tools appeared to be much older than the Harappan. In order to establish the credibility and age of the civilization it was essential to date different objects and artifacts to establish the period of the Cambay civilization. There are many types of dating of archaeological artifacts like carbon dating, Thermoluminesence, OSL, AMS, Dendrochronoly archaeomagnetism, Electron Spin Resonence dating, Pottasium-Argon dating, Cation Ratio dating, etc. In all about 23 numbers datable objects were selected covering both the palaeochannels. From the samples obtained from the marine archaeological sites it was clear that the following methods will be most suitable and a fairly accurate age determination can be obtained from them. These are 14C radiocarbon dating, radio carbon dating by Accelerator Mass Spectrometer, Thermoluminescence and Optically stimulated luminescence.
Radio carbon dating is a method for obtaining age estimates on organic material and is effective from the present back to a maximum of 50,000 BP. Radio active carbon 14C produced in atmosphere is absorbed by plants and the radio active carbon enters the human and animal cycle when the plants are eaten by animal and human beings. The absorbing of 14C is stopped when a living organism dies and 14C starts to disintegrate.. How much 14C is disintegrated and how much is left out can be measured and the rate at which it disintegrates is known. From this the age of organic objects like trees, corals, human remains, shells etc.can be determined. For age determination tests about 50-100 gms of organic material is necessary. In the AMS, an organic sample much smaller of the order of 1 to 2 mgs is enough to calculate the age. This has several advantages over the regular 14C method.The TL method is mainly used for rocks, soil materials, pottery, etc. that were fired. It is based on the principle that almost all natural minerals are thermoluminescnt. Energy absorbed from ionizing radiation frees electrons which are trapped. Later heating releases the trapped electrons producing light. Measurement of the intensity of the light can be used to determine how much time has passed since the last time the object was heated. Natural radioactivity causes TL to build up so that older an object more light is produced. Since a certain amount of heating, generally up to 350 deg.C, is required TL works best for ceramics, cooking hearths, fired bricks, fire cracked rocks or fire treated minerals such as flint or chert.
The OSL is similar to Thermal dating. The mineral in the sediment grains are sensitive to light and when exposed to light the electrons vacate the sediment grains. This process is called recombination or clock setting event. To detect the age the comparision must be made between sediment grain with a known amount of added radiation and sediment grains that are acted upon naturally. This method is suitable for a variety of unheated sediments not older than 500,000 years. This includes silty and sandy sediments that are deposited by water.
The selected samples for various types of dating were sent to some reputed institutes in India, Oxford University, England and to Hannover Germany. Some samples were repeated in different institutes to get confirmation of the age. The results tallied very well. The datable objects were selected to represent both the palaeo channels. However comparitively fewer datable samples were obtained from the southern palaeo channel. In the northern palaeo channel alluvial samples were collected at different depths to have an idea about the age of alluvium as well as the river. Of the total 23 samples that were dated 14C method was followed in 4 samples, TL method in 6 samples and OSL in 13 samples ages were determined.
The alluvium samples of northern palaeochannel were tested at the behest of NIOT by Manipur University. The top alluvium collected just below marine sediment was dated to be around 3000 BP and a slightly lower alluvium gave an age of about 5000 BP. A black alluvium which was somewhat semi consolidated and collected above the river conglomerate gave an age of 19000 BP. Obviously the river has been flowing at least between 19000 years BP, prior to Glacial Maxima and up to 3000 BP. This shows that the palaeo channel in the north was active and a riverine regime existed at least from about 19000 BP. As the area and the palaeo channel to the south was proven to be a hydrocarbon rich zone, several oil and gas producing wells and platforms have been put along with Xmas trees and several oil and gas pipeline are crisscrossing the area. Due to these factors no further sampling than the preliminary one could be undertaken in view of the safety and restrictions in the oil production areas. The water depths of the alluvial samples collected in the northern palaeo channel varied from 20 to 32m.
In the southern township or palaeochannel area six samples suitable for dating were identified. Of these 3 are carbonized wooden samples, one was a sediment sample, one was a fired pottery piece and one hearth material. Sample from the same carbonized wood was sent to National Geophysical Research Institute, Hyderabad, India and Geowissenschaftlicte Gemeinschaftsaulguben, Hannover, Germany for Carbon dating. This was the first sample (Location 21o 03.08’ N ; 72 o30.83 E) from near the southern palaeochannel. This first gave a clue to the age and environment of the civilization. The calibrated age as per NGRI was 9580-9190 BP and as per Hannover Institute it was 9545-9490 BP. It means the age is about 9500 BP and this takes the age by more than 4000 years older than the oldest city civilization of Mesopotomia and a fore-runner to ‘Harappan’ civilization. But this occurred near the top of the stratigraphic coloumn. Because of this it was expected that at the lower levels age will be much older and make the civilization really an ancient one. The wooden piece tested at Birpal Sani Institute at Lucknow, U.P. state gave a calibrated age of 8450 BP. However, two important artifacts were obtained in the near by area at lower levels. These were a nice, thin, pottery and a brownish to red hearth material. Along with it a local clay sediment was also chosen. All the three samples were analysed in the Physical Research Laboratory, Ahmadabad, Gujarat State, using standard Thermoluminescence based pottery dating techniques. As expected the one of the pottery piece whose figure is given, gave a date of 13000 ± 1950 BP. It is an important date. Another pottery piece which was ill-fired, on OSL dating (Location 21 o12.54’ N ; 72 o 30.370’ E) by Oxford University gave an age of 16840 ± 2620 BP. These are the oldest fired pottery pieces obtained sofar in the world. Till the results were out it was from Japan where the oldest potteries were known. The “Jomon” Pottery from the Fukui cave in Kyushu gave 12000 BP uncalibrated age. The pottery findings from Odai Yamamoto gave uncalibrated age of 13500-13800 BP. In the Gulf of cambay civilization already attempts appear to have been made in experimental pottery making. These are seen from effects of fired clays (for making pottery) which gave ages of 20130 ± 2170 BP (Location 21 o 13.720’ N ; 72 o 26.190’ E) and 16600 ± 1150 BP (Location 21 o13.80 ‘N ; 72 o 26.10 E), by OSL as determined by the Oxford University dating lab. The well fired 3 potteries in the northern palaeochannel gave ages of 7506 ± 785 BP, 6097 ± 611 BP (both by Manipur University) and 4330 ± 1330 BP by Oxford University.
Apart from this sun-dried Pottery pieces were collected in these areas. Three of the specimens were dated by OSL facility in Oxford. The results obtained are (1) 31270±2050 BP, (2) 25700±2790 BP and (3) 24590±2390 BP. A black slipped dish which was also sun dried was dated in Oxford by OSL. This gave an age of 26710 ± 1950 BP.
The hearth material from the southern township (Location 21o03.04 N 72o30.70 E) by TL dating from PRL, Ahmedabad gave an age of 10000 ± 1500 BP whereas the hearth material near the top in the northern township gave an age of 3530 ± 330 BP by OSL, Oxford University. One of the charcoal pieces obtained on the northern side was tested by 14C dating in BSIP, Lucknow. It gave calibrated age of 3000 BP. It tallies very well with the age of upper most alluvium in northern Palaeochannel.
The wattle and daub materials which were originally of wood and clay were seen to be burnt but the structure of the wood was well preserved at places (being fossilized). These were tested by OSL at Oxford and by TL at Manipur from the same locations. OSL dating found it to be 5860 ± 720 BP and TL dating determined it to be 5530 ±550 BP. They appear to be a comparatively good match and they reflect the proper ages. They may represent the period at which these structures caught fire.
From the above it is quite clear that the human activity is very evident from about 31000 BP in what is now in the Gulf of Cambay much before the Glacial Maxima at 18000 BP. The ancients were making potteries and were getting them dried initially in the sun. From about 20000 years, it is clear that the ancients are firing the clay to produce pottery. That means they knew how to make, maintain and manage fire. They appear to have succeeded in making fired pottery from about 16800 BP. They knew the art of construction of towns and houses in neat straight line, row after row as picked up by Side Scan Sonar image and wattle and daub structure and from rammed floor. Both the northern and southern townships have continuous habitational sites interspersed with big structures in between. But good quality fired pottery makes it appearance from about 13000 BP. In the southern township (we can call them metropolis) there appears to be organized activity in the form of a community living, a granary (where fossilized food grains were collected) , etc., from about 13000 BP. To the south of this township in the Gulf of Cambay, sidescan Sonar picked up a drowned dead coral colony of 400m long and about 200m wide in a water depths of about 40m substantiated later by sampling. It is a well known fact that these corals live in hardly 2 to 3m water depth very near coastal areas. They require clean environment and good sunlight. Obviously the southern metropolis appears to have been near a sea coast at a particular point of time, when the metropolis itself stood on dry land with a good free flowing river and was a major bustling city. The dating of coral colony like other places by drill core will provide the date of beginning of coral build up in the area and the top sample of coral will reveal the age at which it was drowned giving a direct clue to the drowning of southern metropolis. It is worthwhile noting that the datable objects are found has only up to 8450 BP based on the date of the carbonized wood.
The northern metropolis has well made pottery pieces, wattle daub etc. from about 7506 BP onwards. It indicates well organized city living. Hence it is possible that this metropolis came up after 8450 but much before 7506 BP, may be after the submergence of the southern metropolis. The ancients appear to have shifted and founded the northern metropolis. However the various earlier dates from sun-dried pots etc. indicate that it was under constant habitation.