The Great Sahara Desert & Sub-Saharan Africa
The Stone Age, Bronze Age, and Iron Age each refer to the chief material used for tools and weapons associated with the various stages in the history of man.
At first, these ‘ages’ were used as classifications for dating historic artifacts found in areas such as Europe or Asia, but they’re not referred to quite as often as they once were, because, as it turns out, dates varied drastically for the uses of these materials around the world.
Some civilizations even skipped a period; for example Sub-Saharan Africa went straight from stone to iron skipping the Bronze Age altogether and the American natives never got out of Stone Age until after the era commonly known as European exploration.
Beginning a few hundred years before 10,000 BC all tools and weapons were made of stone / flint, this included axes, spear points, arrow heads, and such. During the latter years (about 7,000 hard years later) of the Stone Age or the Neolithic period, humans began to make limited use of copper (there were / are small amounts of pure copper found in nature), which could be hammered or melted and then formed into tools or weapons. As time marched on in the Neolithic period, the technology of smelting (“melting” out of ore by heating it with fire) emerged in Southwest Asia , thus allowing copper to be extracted from copper ore. While copper can be used for tools and weapons, it is considered to be too soft a material to be reasonably effective. It was eventually discovered that by blending copper with tin, a much harder metal can / could be created that came to be known as bronze.
In any given region, the Bronze Age is considered to have begun when bronze became a material used for constructing tools and weapons. The term “Bronze Age” is typically not used if only a few bronze tools were being made, or if bronze was only being used for creating jewelry.
The Bronze Age of Eurasia (Europe & Asia) spanned from about 3000 BC to 1000 BC. Like the Neolithic period, it began in Southwest Asia , and spread in all directions. It took roughly a thousand years for the Bronze age to cover the entire east-west span of mainland Eurasia, from the Atlantic (Western Europe) to the Pacific (China); naturally, it also spread northward and southward during this time span. So, by 2000 BC, most of Eurasia had made the transition from the Stone Age to the Bronze Age.
Although the Bronze Age spread to North Africa, the Sahara Desert, that’s located in the northern portion of Africa and is the largest hot desert on earth, prevented the Bronze Age from ever reaching that portion of Africa located south of the Sahara Desert, often called Sub-Saharan Africa.
The story of the Iron Age is quite similar. It began in Southwest Asia as well, in about 1000 BC, shortly after smelting pit designs had advanced sufficiently to produce the higher temperatures needed to smelt iron ore. Within about five hundred years, it completely covered the east-west span of Eurasia; within this time line, most of Eurasia had transitioned to the Iron Age by 500 BC.
The Iron Age (like the Bronze Age before it) spread easily to North Africa, but the Sahara Desert greatly delayed its spread to Sub-Saharan Africa. Accordingly, the Iron Age did not reach the southern tip of the African continent until sometime around 500 AD, and remember, this region of southern Africa completely missed the Bronze Age.
The transition from the Bronze Age to the Iron Age was critical not because of any superior physical property of the metal itself as most folks might think, in fact although the Bronze Age came before the Iron Age, bronze is actually superior to iron in several ways; for example: it is less brittle, it has a lower casting temperature, it resists corrosion and rust, and it’s stronger, but then iron is overwhelmingly more abundant than copper and tin. This fact enabled man-kind, for the first time in history, the ability to truly mass-produce metal tools and weapons for both agricultural purposes and warfare alike. Such metal implements are far more effective than stone in both endeavors, a fact that the good folks of the era eagerly accepted.
As for the pre-colonial Americas , the Bronze and Iron ages have little relevance. Prior to the arrival of Europeans in the late 1400’s (think Columbus in 1492), the Bronze Age was reached only by the South American Inca Empire who was conquered by the Spanish in 1532. Even though gold, silver, and copper were commonly used in pre-colonial American art, the Iron Age did not occur at all.
http://en.wikipedia.org/wiki/Neolithic http://www.britannica.com/EBchecked/topic/284517/Inca http://www.theshorterword.com/hist_ancient/classic-ages-stone_bronze_iron.htm http://www.worldatlas.com/webimage/countrys/aflnd.htm