Among these were the manufacture and use of pottery, the discovery of
the smelting of copper and its alloys, and their use in the manufacture of tools
and weapons.
Indus System
In the Indus plains, the picture that we see today was probably the same in
many respects at the time of the earliest settlements on the edge of the plain.
The main channel of the Indus flows through a wide alluvial floodplain
which is of great fertility. Once the agricultural potentials of the new
alluvium were realised, and means were discovered of overcoming the
problems of protecting settlements on the flood-plain from inundation, an
entirely new type of life became possible. Evidently, this development took
place in several stages, reaching its culmination around the opening of the
third millennium BC.
    The first and most important site for consideration is at Mehrgarh. Its
geographical position is essentially one of transition between the upland
valleys of the eastern Iranian plateau and the beginning of the plains of the
Indus system. The transitional nature of its position is fully demonstrated in
the cultural remains found here.
    Out of the six mounds found here, the oldest mound shows a large
Neolithic village which, according to radiocarbon dating, belongs to the sixth
millennium BC. The early transition from nomadic hunting and gathering to
settled agriculture and animal husbandry is documented also by a large
number of animal bones which were found in this mound. The final phase
shows increasing wealth and urbanisation. The top most strata of settlements
at this site are crowded with two-storied buildings. But sometime around the
middle of the third millennium BC the flourishing town of Mehrgarh was
abandoned for unknown reasons.
    In the Indus valley, however, the third millennium BC was a period of
great expansion of settlements. Apparently, population was pressing heavily
on land and new colonies had to be founded in far off places. In the western
valley settlements radiated from Mehrgarh to eastern Iran and southern
Turkmenistan on the one side and to south Baluchistan on the other. In the
eastern valley cities like Harappa, Mohenjodaro, Kalibangan, Surkotada and