Prehistoric / Archaeological Periods
The Stone Age
Archaeologists and historians place the Stone Age as that period of human development when most of the tools used by human beings were made from stone. The evidence available to us currently shows that while the this phase of early human development took place in different parts of the globe, the dates for the Stone Age was different for different parts of the world. It varies depending on the dates assigned to stone implements discovered in a region. As a consequence, dates for the Stone Age have changed with every discovery and the development of dating methods. There is evidence of stone implements having been used in Africa as early as 2.5 million years ago, 1.8 million years ago in Asia, and a million years ago in Europe. Therefore, current theory places the earliest development of human beings in Africa.
During the Stone Age of human development, the earth also experienced an Ice Age some 1.6 million to 10,000 years ago.
The Stone Age in an area ends with evidence of the earliest known metal implements, and generally ends between 6,000 and 4,000 BCE. The Stone Age is further divided into:
• Palaeolithic Age (Old Stone Age - 2.5 million to 15,000 years ago - a time period that spans 95% of human history): the age in which stone tools were chipped or flaked. (see the page on Anghilak cave, Uzbekistan)
• Mesolithic Age (Middle Stone Age, also called the Epipaleolithic Age - 15,000 to 10,000 years ago): the age in which microliths, small, geometric-shaped stone artefacts were attached to wood, antler, or bone to form implements such as arrows, spears, or scythes.
• Neolithic Age (New Stone Age - 10,000 to 6,000-4,000 years ago): the age in which ground and polished stone axes became prevalent.
The Metal Age starts when human beings began to use metal to make tools. For archaeologists, the transition from the stone to the metal age occurs when these metal tools appear alongside stone tools. The type of metal used initially was probably influenced by the surface availability of the metal in natural form, and appears to have been either gold or copper, both being softer, lower melting point metals. A lower melting point was probably critical since the development of metallurgy closely paralleled the ability to produce hotter fires as well as the development of containers to hold and cast the melted metal. The use of gold may even have started with the mechanical shaping of the metal, first in cold form, then heated and softened, and finally melted and cast.
Aryan and Saka legends place the use of gold before the use of copper - possibly a few thousand years earlier. Gold was the more readily available metal in Central Asia. The legends of Ferdowsi state that gold was used in ancient times to make surgical knives used to perform Caesarean operations.
Most of the ancient gold artefacts were plundered, smelted and reused. The unearthing of gold artefacts that predated copper tools, requires finding sites that were hidden or otherwise inaccessible to robbers. We will have to await archaeological evidence to support the legendary evidence that the use of gold preceded the use of copper.
Copper (Chalcolithic, Eneolithic or ∆neolithic) Age
The Copper Age in Central Asia and the rest of the Aryan lands is currently said to begin in the late 5th millennium BCE and lasted for about a millennium (4,300-3,200 BCE) leading in to the Early Bronze Age. Transition from the European Copper Age to the Bronze Age occurs about a millennium later - between the late 4th and the late 3rd millennia BCE.
The use of copper required the development of metallurgy - the science of extracting metal from metal ores - and casting the molten metal in castings.
|Bronze Seal from Anau (Turkmenistan)|
with unknown markings
Bronze is an alloy of copper and tin that is more hard than either pure copper or tin. In addition, bronze has a lower melting point than copper or tin making it easier to form into finished shapes by moulding, casting, or machining. While a harder metal, bronze still did not break easily under stress and was corrosion resistant. Bronze was better suited for weapons and tools than either copper or tin.
The manufacture of bronze required the development of alloy-making technology.
Current reports suggest that the Bronze Age in Central Asia extended from about 3,300 to 1,300 BCE.
With the ability to create higher smelting temperatures came the ability to extract and work with iron, a metal that was in earlier ages considered more precious than gold. Simple iron mixed with some residual slag (the residue when iron is extracted from its ore) is called wrought iron - the earliest form of iron. Wrought iron is weaker than bronze, but because iron was more readily available than copper or tin, wrought iron was less complicated to manufacture than bronze. It was also more easily sharpened than bronze.
Wrought iron was eventually replaced by steel - iron with between 0.02% and 1.7% of carbon. Steel weapons and tools were about the same weight as those of bronze, but stronger.
The Iron Age in Central Asia is estimated to have extended from about 1,300 to 900 BCE.
Categories of Time
The broad categories of time are:
The Cosmological Period consists of time periods in the origin and evolution of the universe. According to current scientific theory the Cosmological Period begins with the Big Bang 13.7 billion years ago and ends with the formation of the earth 4.5 billion years ago.
The Geological period consists of time periods in the origin and evolution of earth. The earth is about 4.5 billion years old. The time from the origin of the earth to the present is divided into super eons, eons, eras and periods.
The Precambrian period is a super eon that is sub-divided into three eons:
• the Hadean Eon (4.5 to 3.8 billion years before present),
• the Archean Eon (3.8 to 2.5 billion years before present),, and
• the Proterozoic Eon (2.5 billion to 570 million years before present)
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The Precambrian Period
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The latest or Phanerozoic Eon (570 million years before present to the present)
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Subdivisions of the Cenozoic Era (65 million years before present to the present)
Prehistoric (Archaeological) & Historic Periods
The Prehistoric Period consists of time periods in the origin and evolution of humankind from about 2.5 million years to about 900 BCE. the Prehistoric Period is divided into the Archaeological Periods of the Stone, Bronze and Iron Ages.
The Historic Period records the activities of humankind from about 900 BCE or from that time when records are available or can re reconstructed. The Historic Period overlaps with the Prehistoric Periods such as the Iron Age when it is possible to reconstruct timelines of a people's history.