The eastern region is mainly alluvial for almost half of its northern length. This is the region through which the gigantic Ganga-Jamuna-Son and the Brahmaputra system drain. Present states of Bihar, West Bengal and Orissa constitute the western wing of the region, the eastern wing which lies east of Bangladesh was earlier known as Assam and the North East Frontier province but is now divided into 7 different states – Assam, Meghalaya, Arunachal, Nagaland, Mizoram, Tripura and Manipur.
The southern region of the western wing and almost the entire eastern wing is formed by mountains and forests which at places almost take up the character of a tropical forest. Palaeolithic sites mainly occur in these mountain rivers or along the higher slopes of adjoining mountains. Prehistoric research in this region seems to be still of an exploratory nature. So far we have only two Lower Palaeolithic sites which have been excavated.
Orissa includes a broad coastal plain, the south east, which has the delta formed by at least two major rivers, viz., Mahanadi and Brahmani. Besides these Burhabalang and Baitarani also drains a large expanse of inner Orissa. In fact if one proceeds upstream along these rivers one can at once get higher up into the numerous undulating hills which continue north-wards into Singhbhum district in Bihar and Midnapur district in W. Bengal.
Nirmal Kumar Bose and Dharani Sen reported their excavation at two quarry-pits in Mayurbhanj district in a valley formed by the ancient Burhabalang River. These two pits, Kuliana and Kamarpara did not yield any satisfactory stratigraphy except for the fact that a rich Lower Palaeolithic culture occurs from a gravel bed extremely stained with laterites.
Subsequently on the clues provided by Valentine Ball who surveyed the area during the last century, the present author could collect more than 1000 Lower Palaeolithic specimens from at least 3 more sites proceeding from Balasore to Bangriposi. The stratigraphic context of all these sites of Burhabalang shows a highly laterized pebbly gravel occurring over very compact lateritic bed.
The implementiferrous bed at places is covered by merely 30″ of soil with redeposited lateritic pellets but at places like Kuliana and Kamarapara, these occur 2 to 3 feet below surface. No fossils have so far been recorded from these beds and therefore an estimation of their chronological status is done purely on a typo-technological basis.
At Kuliana and Kamarpara almost 50 percent of the tools described are chopper-chopping in type. But in association with these both Abbevillian as also Acheulian handaxes and cleavers of a rich variety are identified. Even these are very often seen with pebble butts. At Kamta and Bangriposi, handaxes of a very advanced Acheulian form are seen with a fairly good amount of levalloise flakes but with very few chopping tools.
Choppers are almost conspicuous by their absence. It is significant that Mohapatra, who surveyed the river Mahanadi, recorded almost the same picture under almost similar geo-morphological context. He had, however, formed a kind of typo-technological succession in order to visualize an internal evolution.
It might be quite revealing to see the contents of the three stages in which he divides his collection:
Handaxes, irregularly flaked bifaces, flakes, scrapers, irregularly flaked pebbles.
Handaxes, cleavers, scrapers, cores, flakes and irregularly flaked pebbles.
Handaxes, cleavers, scrapers, points, flakes, cores and irregularly flaked pebbles.
Handaxe forms the ubiquitous component of most of the Lower Palaeolithic culture all over the world. Being a tool type which stays with man for the longest duration, it can have numerous internal variations, cleavers start occurring with the Acheulian handaxes.
His survey identifies three wet phases of which the last two wet phases are recorded by the river in its alluvial deposits. Lower Palaeoliths are believed to be derived from the IInd wet phase.
Further west in Sambalpur district the present author, in collaboration with Ratha, discovered a huge lower Palaeolithic assemblage from one of the tributaries of Mahanadi at Kuchinda. The industry undoubtedly shows pebble preponderance but handaxes and cleavers are by no means lacking.
The evidence of cylinder hammer technique or for that matter levalloise flakes are also recorded. Thus, we see that the Chhotanagpur region of Orissa had maintained a fairly large human occupation around the same time when Narmada was occupied, that is, during late Middle to early Upper Pleistocene.
Districts of Singhbhum in south Bihar and Midnapur in West Bengal were originally surveyed by Ashok Ghosh. A large number of Lower Palaeolithic sites-some of them suspected to be factory sites are reported on the hill slopes along the river Subarnarekha.
Again, we find a generally poor chopper-chopping element in these sites although excellently preserved Late Acheulian handaxes and cleavers in various stages of preparation are identified. Further east in the districts of both Bankura and Birbhum, which have parts of them covered by lateritic extension, have also yielded several Lower Palaeolithic assemblages. Dilip Chakravarty has listed most of these finds resulting out of his surveys.
The concentration of these sites is distinctly thinned out as one progress into W. Bengal. In fact, most of them start occurring with a profusion of microliths. The stratigraphy of the region seems to be extremely ambiguous, notwithstanding the several claims of ‘in-situ’ finds. Apparently all these are incorporated in later lateritic wash of kankar and pebbles.
In the recent years a spectacular Acheulian open-air primary site has been reported by Pant and Jayaswal (1991). The site called Paisra is in Monger district of Bihar.
The unique features of the site can be summarised briefly:
(i) The site has preserved unmistakable evidence for habitational floors of the Acheulians and it spreads over an area of several hundred square meters.
(ii) Associated with the tools are found a large number of finished and half-finished implements, flakes, cores and other debitages. Significantly even hammer-stones, anvils and lumps of raw material have also been recovered.
(iii) The excavation has revealed several post-holes and also stone alignments. These have been interpreted as demonstrating the existence of more than one type of structures.
(iv) Significantly Paisra had also been a camp site of the Mesolithic settlers in the region and has a date which puts it in the 6th millenmium B.C. Incidentally this is the only radio carbon date for Mesolithic known to us from eastern India.
The tools analysed from a total of 7 localities excavated show a limited number of Upper Acheulian handaxes and cleavers and the dominant feature is of levalloise flakes and flake tools. Varieties of flake tool types dominate the industry.
In the eastern wing most of the Lower Palaeolithic sites known till date come from Meghalaya. T.C. Sharma and his students have surveyed large areas around Rongram and the adjoining hilly slopes and discovered more than 30 Lower Palaeolithic sites. There is no doubt that these come from a gravel bed but whether these could be linked with the Narmada basal gravel cannot be decided primarily because of the absence of fauna.
The tools collected are predominantly chopper-chopping in type although rarely a handaxe or a cleaver with pebble butt can also be seen. It is important to note that since these areas record highest rainfall in the world, colluviations are likely to be a very active phenomenon and hence identification of gravel beds should not be hurriedly linked with Pleistocene episodes.