Geological Chronology

©Edward J. Vajda

Pleistocene, a word which means "most recent," is the geological term for the period of Earth's history from 1.6 million years ago to 8,000BC. This period is characterized by dramatic climatic fluctuations between warmer periods and periods of intense cold (another word for the Pleistocene is the Ice Age). In the coldest times during the Pleistocene, large areas of northern Europe and Western Siberia (and much smaller areas of northeastern Siberia) were covered with thick ice sheets. In Western Siberia, these ice sheets at times blocked the flow of the immense Ob River, so that the entire Ob River basis was at times a swampy lake. Archeologists divide the Pleistocene into a lower (the oldest), middle, and upper (the most recent) period.

Lower Pleistocene (1.6 million years to 730,000 years ago). This was the time when Homo erectus populated temperate areas of Africa, Europe and Asia. Homo erectus remains have been found in northern China, but not in the northern parts of Eurasia.

Middle Pleistocene (730,000 to 128,000 years ago). This was the time when Archaic Homo sapiens appeared, as well as Homo neanderthalis. Digs in southern Siberia and the northern Pacific coast show evidence that these form of early humans lived there as early as 200,000BC.

Upper Pleistocene (128,000 to 10,000 years ago, or 8,000BC). During this time anatomically modern Homo sapiens appeared. The earliest evidence of modern human habitation in northern Eurasia once again comes from the area from the Altai mountains to the Amur valley, where cites dating to at least 40,000BC have been uncovered. It is very probable that the entire habitable southern and easternmost portions of Siberia was the home of small nomadic bands of Stone Age hunters as early as 35,000BC. Beautiful rock paintings of horses and other animals have been found as far north as the upper Lena River valley and date earlier than 25,000BC. (This was a time when most of western Siberia was still covered in ice or water.)

During this time, either before the last great cold period (before 25,000BC or after 12,000BC) bands of Siberians crossed over into the northernmost extremities of the the Asian Pacific Rim and entered present-day Alaska, quickly populating the Americas (all habitable areas of North and South America show evidence of settlement by 9,000BC).

Holocene, a word which means "fully recent," is the geological term for the present, post-Ice Age period of Earth's history beginning about 8,000BC. During this period the last of the great ice sheets melted from northwest Eurasia. The Ob River began to empty into the Arctic, draining much of the water from Western Siberia and opening that area to modern human settlement for the first time. The Holocene is the time when peoples moved from the southeastern and Pacific fringes of Siberia into the Arctic and northwestern parts. The Native Siberian peoples surviving today do not show evidence of being closely related to Native Americans.

The climate changes set in motion at the end of the Pleistocene, coupled by overhunting, also killed off many big-game animals in the Northern Hemisphere. Even more important, the whole East Asian continental shelf was flooded and became the Yellow Sea.

Perhaps most important, climactic changes occurring the end of the Ice Age also seems to have led to the adoption of sedentary farming by peoples living in Southwest Asia (present-day Turkey, Iraq) and China. Thus, in terms of human culture, the beginning of the Holocene coincides with the Neolithic Revolution (see below).

World Culture Ages

The conventional ages of world culture include the following (note that each begins at a different time in different parts of the world):

A. The Stone Ages, prior to the smelting of metal

1. Paleolithic (or Old Stone Age of hunter-gatherer existence, which began with the rise of tool-making humans and ended in Southwest Asia by 12,000BC). The Paleolithic ended with the extinction of many of the Northern Hemisphere's large mammals (mastodons, mammoths, giant elk, etc).

2. Mesolithic (the Middle Stone Age, or age of transition the big game hunters of the Paleolithic to more diverse economies (12,000-8,000BC) In certain temperate areas, out of these mesolithic economies farming and settled life were later to develop, a period called the Neolithic. Anthropologists and archeologists sometimes dilineat an intermediate stage between the Neolithic and Mesolithic: hunter-gatherer societies which have acquired pottery but have not yet settled and begun farming are sometimes called sub-neolithic. Sometimes the entire time before the appearance of farming (the Paleolithic proper and the Mesolithic, that is, everything before 8,000BC) is simply called the "Paleolithic."

3. The Paleolithic and Mesolithic essentially coincide with the Pleistocene Epoch. With the advent of the Holocene, we see the development of the Neolithic (the New Stone Age, or the age of sedentary farmers, which began first in Southwest Asia around 8000BC, and later, perhaps as early as 5,000 BC in northern China). The advent of sedentary farming is sometimes termed the Neolithic Revolution, and a revolution it was, since areas which developed settled farming communities experienced up to a tenfold increase in population. In general, ethnic groups who never underwent a transition to either a farming or a pastoral nomadic (domestication of cattle, horse, sheep, goat, etc.) way of life, but instead remained hunter-gatherers, are those who today constitute the endangered "small peoples" of the world. Such groups include a large percentage of the native peoples of northern Eurasia.

Note that the word "Neolithic" or "Neolithic-aged" is often used to describe any archeological site dated after 8,000BC, including those in Siberia and other areas of the world where farming and sedentary civilization had not yet developed.

B. The Metal Ages, after the smelting of metal

After the Neolithic--the last of the Stone Ages--come the various "Metal" Ages, named after whatever dominant metal was used instead of stone. Until the coming of the Russians, most Siberian peoples (except those of southern Siberia) remained essentially mesolithic hunter gatherers until after the coming of the Russians in 1582.

1. Eneolithic (also called the Copper Age, or Chalcolithic, pronounced [kæl-ka-LITH-ik], which began in Southwest Asia by 4000BC). The ancient Indo-Europeans spread the Copper Age throughout the southern steppes of Eurasia.

2. The Bronze Age (beginning as early as 2500BC in the Western Mediterranean; the Bronze Age may have begun independently in southern China and northern Thailand). The Indo-European ancestors of the Iranians and Hindu peoples of north India spread the Bronze Age spread throughout the steppe zone of Eurasia.

3. The Iron Age (beginning as early as 1200BC in what is now Turkey and, once again, spreading across the steppes to China as well as eastward into northern Europe).

4. It is fashionable to call the time of complex machinery which began c. 1700 AD in Europe and North America the Industrial Age. Russia entered the Industrial Age in the early 18OO's; China and much of northern Eurasia may can only be said to have entered this age during the past century.