The Formation Process of Tianzhu Mountain (1) Coping Tianzhu Mountain ‖ Punching

The information and pictures are all from the story of "Hiking Reptiles: Protected Areas". Original title: "Yunxiu Wandi is hundreds of millions of years, and Tianzhu is ten years." This article is used for popular science propaganda and pays tribute to the author!

During the Triassic period about 250-220 million years ago, the crustal movement was active, and the Yangtze plate collided with the North China plate on a large scale, creating a typical continental-continental collision orogenic belt-Dabie orogenic belt.

During this period, the relative positions of several major plates in China have been relatively clear, and the collision between China-Korea plate (of which North China plate is a part) and Yangtze plate has produced Dabie orogenic belt.

At this stage, the Yangtze plate dived under the North China plate and plunged into the mantle more than 80 kilometers below the surface. The rocks on the surface have experienced high temperatures.

Mild ultrahigh pressure forging into ultrahigh pressure metamorphic rocks.

The Yangtze plate collided with the North China plate, and the rocks subducted into the mantle became ultrahigh-pressure terranes. Later, because of their relatively low density, they separated from the sinking high-density rocks, the Yangtze plate floated up and the strata gradually rose. At the same time, minerals such as diamond and coesite were formed in the high temperature and high pressure environment of the mantle.

At the right time, coesite was formed by ultra-high pressure metamorphism, and it usually takes about 80 kilometers underground to reach this high pressure. It is wrapped by eclogite layer by layer and becomes a part of ultrahigh pressure metamorphic rocks. Hide the secret of "inner world" in it and let researchers see the changes in the depths of the earth. Under different temperature and pressure conditions, various forms of carbon (such as graphite and diamond) will be transformed into each other.

In Cretaceous, tectonic movement led to magma eruption and a large number of granitic magma invaded, which made the granite bodies widely distributed in Tianzhu Mountain area.

During this period, the crust in the eastern part of China expanded and melted under reduced pressure, and a large number of granitic magma rose and emplaced, carrying ultra-high pressure rocks to rise and cool to form Tianzhu Mountain granite body. After subduction, ultrahigh-pressure metamorphic rocks at the bottom of the earth's crust are exposed to the earth's surface under orogeny, making Tianzhu Mountain one of the largest and best preserved ultrahigh-pressure metamorphic terranes in the world.

There are more than 20 ultrahigh-pressure metamorphic belts with time, especially in China and Dabie Mountain (Tianzhu Mountain). 1987, Xu Zhiqin pointed out in his paper that coesite eclogite developed in Acorus calamus in Dabie Mountain. 199 1 year, Professor Xu Shutong first discovered micro-diamond in eclogite in Xindian, Dabie Mountain. These rediscovered rocks prove that continental crust rocks can dive to the depth of the mantle below 80 kilometers, which is a deep geological process that humans have never realized.

The original rock is rich and complex sandstone, which was transformed by eclogite facies to form ultra-high pressure metamorphic rock. The main minerals are jadeite, Yingshi and garnet. The study of this discovery has led to the formation of modern ultra-high pressure metamorphism theory and great changes in modern geology.

Tianzhu Mountain, as the starting point of ultrahigh pressure rock research in China, is also the center of this "academic storm".

With the movement of the Tanlu fault zone, the earth was cut, causing the Dabie orogenic belt to slide about 550 kilometers to the north, forming the geological structure of the Dabie-Sulu orogenic belt seen today. The Tancheng-Lujiang fault zone stretches for more than 2,400 kilometers in China, passing through different structural units in eastern China, and its southern segment was displaced and staggered in Yanshan period.

The activity of the fault zone has deeply influenced the landform of Tianzhu Mountain, and the mountain basin is distinct, which constitutes the distinct surface pattern of Tianzhu Mountain. The difference between Xishan and Dongpen is very obvious. Tianzhu Mountain on the west side is uplifted, forming a granite peak forest landform. The earthquake caused by the activity of fault zone is easy to make the mountain peak collapse, and the rock may crack and fall along the joints after being broken by external force.

Due to tectonic activity and long-term weathering and denudation, the granite peak forest collapsed and fell off, forming a "Tianzhu Mountain" granite landscape, with strange stones and caves scattered everywhere.

Due to the homogeneous texture of granite, many external forces can make it egg-shaped and spherical, and weathering is one of them.

There are 47 granite peaks above the altitude of 1000 meters in Tianzhu Mountain, of which Tianzhu Peak is 1489.8. Straight into the sky, like a pillar in the sky.

All the stones are strange. White clouds surround rocks, green flowers cover rocks, and rocks with strange shapes seem to be reborn in white clouds. For example, the elephant trunk stone, the wangong statue and Ying Ge's dance are all lively.

The statue of Wan Gong stands at the mouth of the mysterious valley, nearly two meters high, with distinct facial features, resembling Wan Gong, the "ancestor of Anhui" in the record.

No holes. There is a cave in the rock. The mysterious valley, which is more than a thousand meters long, has a huge scale and many caves, and is known as "the first secret mansion of granite caves in China".

The mysterious valley is 1000 m long, and the drop is 100 m. There are big caves everywhere: Dragon Palace, Maze, Tiangong and Xiaoyao Palace. Taoism regards this as a blessed land, and calls it Sixuan Cave House.

All spring is beautiful. Diving, Anhui River and Tianzhu Mountain form a unique landscape of "two rivers and one mountain". Waterfalls, wells and ponds, streams and springs, rivers and lakes are connected, and the springs are full of snow waterfalls, flying and thundering.

Loose and proud. Granite is the fullness of Tianzhu Mountain. Huangshan pine is the loose tendon of Tianzhu Mountain, hidden in the arms of Tianzhu Mountain, clear and sparse, not abrupt, with lofty sentiments.

The eastern side of Tianzhu Mountain descended in the fault zone activity, forming a buried hill continental fault basin and further forming a river and lake alluvial plain.