Quaternary period of the Cenozoic era: description, history and inhabitants

The last geological and present-day Quaternary period was singled out in 1829 by the scientist Jules Denouye. In Russia it is also called anthropogenic. The author of this name in 1922 was the geologist Alexei Pavlov. By his initiative, he wanted to emphasize that it is this period that is associated with the appearance of man.

Uniqueness of the period

In comparison with other geological periods, the Quaternary period is characterized by extremely short duration (only 1.65 million years). Continuing today, it remains incomplete. Another feature is the presence in the Quaternary sediments of the remains of human culture. This period is characterized by multiple and sharp climatic changes that have dramatically influenced natural conditions.

Periodically recurring cold snaps led to the glaciation of northern latitudes and the moistening of low latitudes. Warming caused exactly the opposite effect. Sedimentary formations of the last millennia are distinguished by the complex structure of the section, the relative short-term formation and variegated formation. The Quaternary period is divided into two epochs (or departments): Pleistocene and Holocene. The border between them lies at the level of 12-thousand years ago.

Migrations of flora and fauna

From its very beginning, the Quaternary period was characterized by a close to the modern plant and animal world. Changes in this fund entirely depended on a series of cooling and warming. With the onset of glaciations the cold-loving species migrated to the south and mixed with the aliens. During the periods of increasing mean temperatures, the reverse process occurred. At that time, the area of settlement of the temperate warm, subtropical and tropical flora and fauna expanded greatly. For a while, entire tundra associations of the organic world disappeared.

Flora had to adapt several times to the cardinally changing conditions of existence. Many cataclysms during this time marked the Quaternary period. Climatic swings led to depletion of broadleaf and evergreen forms, as well as the expansion of the range of herbaceous species.

Evolution of mammals

The most notable changes in the animal world have affected mammals (especially the ungulate and proboscis Northern Hemisphere). In the Pleistocene, a number of thermophilic species died out due to sharp climatic jumps. At the same time, for the same reason, new animals appeared, better adapted to life in harsh environmental conditions. Its peak was reached by the extinction of fauna during the Dnieper glaciation (300-250 thousand years ago). At the same time, the cooling determined the formation of the platform cover in the Quaternary period.

At the end of the Pliocene the south of Eastern Europe was home to mastodons, southern elephants, gipparions, saber-toothed tigers, Etruscan rhinoceroses, etc. In the west of the Old World lived ostriches and hippopotamuses. However, already in the Early Pleistocene the animal world began to change radically. With the onset of the Dnieper glaciation, many thermophilic species migrated to the south. In the same direction, the distribution area of the flora shifted. The era of the Cenozoic (the Quaternary period in particular) tested all forms of life for strength.

Quaternary bestiary

On the southern borders of the glacier, such species as mammoth, woolly rhinoceros, reindeer, musk muskox, lemmings, white grouses appeared for the first time. All of them lived exclusively in cold areas. Cave lions, bears, hyenas, giant rhinoceroses and other heat-loving before living in these regions became extinct.

The cold climate was established in the Caucasus, in the Alps, Carpathians and Pyrenees, which forced many species to leave the highlands and settle in the valleys. Woolly rhinoceroses and mammoths occupied even southern Europe (not to mention the whole of Siberia, where they came from in North America). The relic fauna of Australia, South America, South and Central Africa is preserved due to its own isolation from the rest of the world. Mammoths and other animals, well adapted to the conditions of severe climate, died out at the beginning of the Holocene. It is worth noting that, despite numerous glaciations, about 2/3 of the Earth's surface has never been affected by the ice sheet.

Human development

As mentioned above, various definitions of the Quaternary period can not do without "anthropogenic". The rapid development of man is the most important event of this historical period. The place of appearance of the most ancient people today is East Africa.

Ancestral form of modern man - australopithecines, belonging to the family of hominids. According to various estimates, they first appeared in Africa 5 million years ago. Gradually the australopithecines became bipedal and omnivorous. About 2 million years ago they learned how to make primitive tools. Thus a skilled man appeared . A million years ago, Pithecanthropus formed, whose remains are found in Germany, Hungary and China.

Neanderthals and modern people

350 thousand years ago there were paleanthropines (or Neanderthals), extinct 35 thousand years ago. Traces of their activities are found in the southern and temperate latitudes of Europe. Paleanthropines have been replaced by modern people (neoanthropes or homo sapines). They were the first to penetrate to America and Australia, and also colonized the numerous islands of several oceans.

Already the earliest neanthropines almost did not differ from today's people. They adapt well and quickly to climate change and masterfully learned how to process stone. These hominids acquired bone products, primitive musical instruments, objects of fine art, ornaments.

Quaternary period in the south of Russia left numerous archaeological monuments related to neanthropines. However, they also reached the northernmost regions. Cooling people have learned to survive with the help of fur clothes and fires. Therefore, for example, the Quaternary period of Western Siberia was also marked by the expansion of people who tried to master new territories. 5 thousand years ago the Bronze Age began , 3 thousand years ago - the Iron Age. At the same time in Mesopotamia, Egypt and the Mediterranean foci of ancient civilization were born.

Minerals

Scientists divided into several groups of minerals, which left us a Quaternary period. Deposits of the last millennia refer to a variety of placers, nonmetallic and combustible materials, ores of sedimentary origin. Coastal-marine and alluvial deposits are known. The most important minerals of the Quaternary period: gold, diamonds, platinum, cassiterite, ilmenite, rutile, zircon.

In addition, iron ore of lake and lacustrine origin is of great importance. The same group includes manganese and mednonadadievye deposits. Such accumulations are common in the World Ocean.

Wealth of bowels

Even today, equatorial and tropical rocks of the Quaternary period continue to erode. As a result of this process laterite is formed. Such a formation is covered with aluminum and iron and is an important African mineral. Metal-bearing crusts of the same latitudes are rich in deposits of nickel, cobalt, copper, manganese, and also refractory clays.

In the Quaternary period important nonmetallic minerals also appeared. These are gravel (they are widely used in construction), molding and glass sands, potassium and rock salts, sulfur, borates, peat, and lignite. In the Quaternary sediments groundwater is enclosed, which is the main source of clean drinking water. Do not forget about the permafrost rocks and ice. In general, the last geological period remains the crowning of the geological evolution of the Earth, which began more than 4.5 billion years ago.