Alpine folding is an era in the history of the formation of the earth's crust. In this era, the highest mountain system in the world - the Himalayas. What characterizes the era? What other mountains of alpine folding exist?
Earth crust folding
In geology, the word “fold” is not far from its primary meaning. It denotes the area of the earth's crust in which the rock "crumpled." Typically, the breed lies in horizontal layers. Under the influence of the internal processes of the Earth, its position may change. It bends or squeezes, overlapping adjacent areas. This phenomenon is called folding.
The folding occurs unevenly. The periods of their appearance and development are named in accordance with geological eras. The oldest is Archean. She finished forming another 1.6 billion years ago. Since that time, the 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 the alpine era of folding. In the history of the formation of the earth's crust, it takes the last 60 million years. The name of the era was first voiced by French geologist Marcel Bertrand in 1886.
Alpine folding: characteristic of the period
The era can conditionally be divided into two periods. In the first, deflections actively appeared in the earth's surface. Gradually, they filled with lava and sedimentary deposits. The bark uplifts were small and very local. The second stage was more intense. Various geodynamic processes contributed to the formation of mountains.
Alpine folding has formed most of the largest modern mountain systems, which 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 of the planet and differ in climatic zones, as well as altitudes.
The era has not yet ended, and the mountains continue to form now. This is evidenced by seismic and volcanic activity in various regions of the Earth. The folded area is not continuous. Ranges are often interrupted by depressions (for example, the Ferghana 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, extend in the latitudinal direction. They almost completely cross Eurasia. They begin in North Africa, pass through the Mediterranean, Black and Caspian seas, stretch through the Himalayas to the islands of Indochina and Indonesia.
Alpine folding mountains include the Apennines, Dinars, Carpathians, Alps, Balkans, Atlas, the Caucasus, Burma, the Himalayas, the Pamirs, etc. They all differ in their appearance and height. For example, the Carpathian mountains are medium-high, have smooth outlines. They are covered by forests, alpine and subalpine vegetation. Crimean mountains, in contrast to them, are more abrupt and rocky. They are covered by more mean steppe and forest-steppe vegetation.
The highest mountain system is the Himalayas. They are located in 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 adjacent to them. A volcanic ring is located around 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 east coast of the ocean, it includes the Andes, Cordillera, Aleutian Islands and the Tierra del Fuego archipelago.
This area has earned the name "ring of fire" due to the fact that most of the planet's volcanoes are located here. About 330 of them are operational. In addition to eruptions, the largest number of earthquakes occur within the Pacific belt.
Part of the ring is the longest mountain system of the planet - the Cordillera. They cross 10 countries in North and South America. The length of the mountain range is 18 thousand kilometers.