Alpine folding is an epoch in the history of the formation of the earth's crust. In this era, the highest mountain system in the world, the Himalayas, was formed. What characterizes the era? What other mountains of Alpine folding exist?
Folding of the earth's crust
In geology, the word "fold" is not far from its primary meaning. It denotes a section of the earth's crust in which the rock is "crumpled". The rock usually occurs in horizontal layers. Under the influence of the internal processes of the Earth, its position can change. It bends or squeezes, overlapping adjacent areas. This phenomenon is called folding.
The formation of folding occurs unevenly. The periods of their appearance and development are named in accordance with geological epochs. The most ancient is the Archean. It finished forming 1.6 billion years ago. Since that time, numerous external processes of the planet have turned it into plains.
After the Archean, there were Baikal, Caledonian, Hercynian, Mesozoic folding. The most recent is alpineera of folding. In the history of the formation of the earth's crust, it occupies the last 60 million years. The name of the era was first announced by the French geologist Marcel Bertrand in 1886.
Alpine folding: characteristics of the period
The era can be conditionally divided into two periods. In the first, deflections actively appeared in the earth's surface. Gradually they were filled with lava and sedimentary deposits. The uplifts of the crust were small and very localized. The second stage was more intense. Various geodynamic processes contributed to the formation of mountains.
Alpine folding formed most of the largest modern mountain systems that are part of the Mediterranean Fold Belt and the Pacific Volcanic Ring. Thus, folding forms two large areas with mountain ranges and volcanoes. They are part of the youngest mountains on the planet and differ in climatic zones, as well as heights.
The era is not over yet, and the mountains continue to form even now. This is evidenced by seismic and volcanic activity in various regions of the Earth. The folded area is not continuous. The ridges are often interrupted by depressions (for example, the Fergana depression), in some of them seas have formed (Black, Caspian, Mediterranean).
Mediterranean belt
Mountain systems of Alpine folding, which belong to the Alpine-Himalayan belt, stretched in a latitudinal direction. They almost completely cross Eurasia. Start in North Africa, go throughThe Mediterranean, Black and Caspian Seas stretch through the Himalayas to the islands of Indochina and Indonesia.
Mountains of Alpine folding include the Apennines, Dinars, Carpathians, Alps, Balkans, Atlas, Caucasus, Burma, Himalayas, Pamirs, etc. All of them differ in their appearance and height. For example, the Carpathian Mountains are medium high, have smooth outlines. They are covered with forests, alpine and subalpine vegetation. The Crimean mountains, in contrast, are steeper and more rocky. They are covered with more stingy steppe and forest-steppe vegetation.
The highest mountain system is the Himalayas. They are within 7 countries including Tibet. The mountains stretch for 2,400 kilometers in length, and their average heights reach 6 kilometers. The highest point is Mount Everest with a height of 8848 kilometers.
Pacific Ring of Fire
Alpine folding is also associated with the formation of the Pacific Ring of Fire. It includes mountain ranges and depressions that adjoin them. The volcanic ring is located along the perimeter of the Pacific Ocean.
It covers Kamchatka, the Kuril and Japanese Islands, the Philippines, Antarctica, New Zealand and New Guinea on the west coast. On the eastern coast of the ocean, it includes the Andes, the Cordilleras, the Aleutian Islands and the Tierra del Fuego archipelago.
The name "ring of fire" this area has earned due to the fact that most of the world's volcanoes are located here. Approximately 330 of them are active. In addition to eruptions,the greatest number of earthquakes occur within the Pacific belt.
Part of the ring is the longest mountain system on the planet - the Cordillera. They cross 10 countries that make up North and South America. The mountain range is 18,000 kilometers long.
