What is the difference between horizontal and vertical motion of the earth s crust? Why fold faults

The direction of movement of the rock layer is different, the fold is the bending and deformation of the rock layer caused by the extrusion force in the horizontal direction, so it is a horizontal movement, and the fault is more complex, if the rock layer is stressed (whether it is pressure or tension) and fractures, the obvious relative displacement of the rock layer on both sides of the fault surface is called a fault, if the rock layer on both sides is displaced in the horizontal direction, it is a horizontal fault, which is not obviously mentioned in the middle school textbook, if you have the impression, there is a growth boundary in the plate boundary type, such as ridges, faults, etc., Here are the horizontally moving faults, and the other is the displacement of the rock layers on both sides in the vertical direction, that is, the vertically moving faults, the rising ones form blocky mountains, and the sinking ones form valleys or basins.

What is the difference between horizontal and vertical motion of the earth's crust?

The direction of movement of the rock formations is different.

The fold is a horizontal movement caused by the horizontal compression force of the rock layer.

Faults are more complex, if the rock layer is forced (whether it is pressure or tension) to fracture, the rock layer on both sides of the fault surface and then has obvious relative displacement is called a fault, if the rock layer on both sides is displaced in the horizontal direction, it is a horizontal fault, which belongs to horizontal movement, which is not obviously mentioned in the middle school textbook, if you have the impression, there is a growth boundary in the plate boundary type, such as ridges, faults, etc., here is a horizontal movement of the fault, and there is a displacement of the rock layers on both sides in the vertical direction, that is, the vertical movement of the fault, The rising ones form blocky mountains, and the sinking ones form valleys or basins.

The main difference between horizontal and vertical motion of the earth's crust is the direction of motion. Horizontal motion refers to the displacement and movement of crustal blocks in the horizontal direction, and this movement often leads to fold structures and fractures. Vertical motion, on the other hand, refers to the displacement and movement of crustal blocks in the vertical direction, which often causes the crust to lift or sink to form plateaus or basins.

A fold fault is a product of horizontal movement. When a rock layer is subjected to a horizontal compressive force, it causes the rock layer to bend and fracture, forming a folded structure. These formations usually appear as a series of continuous mountains, hills, etc.

In addition, it should be pointed out that the form and direction of movement of the earth's crust are very complex, and horizontal and vertical movements often exist at the same time and interact with each other. Therefore, for the specific crustal movement, it is necessary to combine the specific geological structure and crustal kinematic theory to analyze and explain.

Direction of horizontal movement of fault lines and crust: The plate moves both horizontally and vertically. But as far as faults are concerned; It is the crust that moves horizontally over a small distance and a large distance that moves vertically.

The fault line is the outcropping line of the fault plane on the ground, so it is the same as the outcrop line of the inclined rock formation, and the occurrence of the fault plane can be judged by the "V" shaped rule. Generally, on the geological map, the fault line will be marked with an arrow symbol to indicate its inclination, fault line (the red line indicates the fault trend, the arrow indicates the fault inclination, and the number indicates the fault dip angle).

Classification of faults. Classification according to the mechanical properties of faults:

Compressive faults, formed by compressive stress, strike perpendicular to the direction of the main compressive stress, mostly in the form of reverse faults, the section is soothing wave-like, the fault bandwidth is large, and there are often fault breccias.

Tensile faults, formed under the action of tensile stress, their strike is perpendicular to the direction of tensile stress, often normal faults, the fault plane is rough, mostly jagged.

Torsional faults, formed under shear stress, have an intersection angle of less than 45° with the direction of principal compressive stress, and often occur in pairs. The fault plane is straight and smooth, and there are often abrasion marks.

Horizontal motion refers to the combination and separation of the earth's blocks, when the force of horizontal motion is large enough to cause the extrusion may cause vertical motion, the difference between the trillions of horizontal motion and vertical motion of the earth's crust is:

1. The direction of horizontal motion is the horizontal displacement of crustal materials, while the direction of vertical motion is perpendicular to the earth's surface;

2. The horizontal movement of rock strata is manifested by the bending and uplift of rock strata, or the manifestation of vertical movement of floppy rock strata with fault opening and vertical movement is the uplift or descent of the earth's crust;

3. The result of horizontal movement is the huge folded mountains, rift valleys, and oceans, while the result of vertical movement is the ups and downs, and the changes of sea and land skins.

The reasons for the change of sea and land are: one is the movement of the earth's crust, the second is the rise and fall of sea level, and the third is human activities.

According to the direction of motion, it can be divided into horizontal motion and vertical motion. Vertical movement, also known as lifting movement, land transportation Zhengdong Chang movement, it makes the rock layer show uplift and the decline of adjacent areas, can form plateaus, fault block mountains and depressions, basins and plains, but also can cause sea invasion and sea retreat, so that the sea and land change. Horizontal motion refers to the movement of rock formations that make up the earth's crust in a direction parallel to the earth's surface, also known as orogeny or fold movement.

This movement can often form huge folded mountain systems, as well as giant depressions, island arcs, trenches, etc.

Crustal movement controls the distribution of sea and land on the earth's surface, affects the occurrence and development of various geological processes, forms various tectonic forms, and changes the original state of rock formations, so some people also call crustal movement tectonic movement. According to the law of motion, the movement of the earth's crust is mainly horizontal motion, and some lifting motion is a phenomenon derived from horizontal motion.

Although there are various forms of neotectonic movement, there are two basic types: horizontal movement and vertical movement. (1) Horizontal movement: Horizontal movement is the most direct manifestation of plate movement. A large number of data have proved that the fast speed, long duration and large amplitude of horizontal movement are the main ways for the new structure to move the potato.

At present, the observed traces of horizontal movement are mainly the horizontal displacement of various landforms and water systems, such as the dislocation and deformation of the shoreline, mountain edge line and ridgeline in the lake, the asymmetrical offset of the alluvial fan, and the right-angle bend of the water system. The displacement amplitude of horizontal motion is generally large, such as the right-handed translation of the Honghe fault, which caused the dislocation of the water system by 5 km, and the horizontal displacement of the Altyn fault since the Neo-Tertiary (Neogene) is up to 4 5 km. The world-famous San Andres Fault caused a displacement of 21m in 1906 and a break in Altyn in 1931, causing a horizontal displacement of 11m.

2) Vertical movementVertical movement is one of the main manifestations of neotectonic movement, which has left its own traces on topography and sedimentation, and is easy to observe, such as obvious contrast in the landform, layered landform plane formation, multi-stage eruption basalt, razor plane, multi-level terrace, multi-stage superimposed alluvial fan, etc., all belong to the neotectonic characteristics dominated by vertical movement. There are two types of vertical movements: active fault vertical motion and colpine vertical motion, the former is mainly the differential lifting activity of fault blocks, often forming fault basins and fault block mountains, such as the Fenwei graben and the mountains on both sides; The latter is mainly manifested in large-scale arch uplift and depression, such as the Ordos Plateau and Yushe Basin. Generally speaking, the amplitude of vertical uplift movement is thousands of meters to more than ten kilometers, such as the thickness of the Cenozoic sediments of the Fenwei graben is four or five kilometers, and the relative height of the Middle and Old Tertiary (Paleogene) planes in the mountains on both sides is also about 3,000 meters, and the total relative movement amplitude is about 10,000 meters.

It is worth noting that the above two basic forms of movement can act independently in different geological areas, or they can act on the same area at the same time through mutual transformation. For example, near the collision zone of plates, due to the horizontal collision of plates of the same nature, the earth's crust is shortened laterally, the thickness is increased, and the surface is lifted, resulting in vertical lifting motion. For example, at the end of the Old Tertiary (Paleogene), the Indian plate moved horizontally northward at a speed of 5 cm a and collided with the Eurasian plate, which caused the Himalayas to be strongly uplifted, and at the same time caused the uplift and thickening of the earth's crust on the Tibetan Plateau, which has risen by about 2000 3000 m since the Pliocene (Ma Xingyuan, 1986).

To a large extent, this is due to the interconversion of horizontal-vertical movements.

1) Overview of tectonic movementsTectonic movements mainly refer to the geological processes caused by the deformation, displacement, and the accretion and extinction of the ocean floor caused by the internal forces of the earth. At present, the tectonic movements that have occurred since the Neogene (Late Tertiary) are called neotectonic movements; The new tectonic movements that have occurred since the beginning of the year are called modern tectonic movements. (2) Basic characteristics of tectonic movements1

Tectonic motion is directional, and tectonic motion includes two types: horizontal motion and vertical motion. (1) The horizontal movement is manifested as the horizontal extrusion or horizontal extension of the lithosphere, which causes the rock layer to fold and fracture, and even form huge folded mountains or huge grabens and rifts. Relatively speaking, horizontal motion is difficult to observe, Chang Xiangtan uses a triangulation network to find out, such as the San Andres fault near the west coast of the United States, which has been proved by triangulation that the horizontal staggering is up to 480km.

Another example is the Lujiang fault in eastern China, which is estimated by geological markers to be 740km flat on the east and west sides of the fault. (2) Vertical movement is generally manifested as a large-scale upward and downward movement, forming large-scale uplift and depression, causing transgression and retreat. Generally speaking, vertical motion is easy to identify, but vertical motion is slower than horizontal movement.

At different times in the same area, the upward and descending movements often alternate. In addition, vertical movement is always one after the other. In the interior of the continents, vertical motion can be detected by geodetic.

Various signs can be used to verify it at the seaside. For example, the three Dali in front of the temple of Poturio on the coast of the Bay of Naples, Italy, were once submerged into the sea due to the rise and fall of the earth's crust, and people can judge the amplitude of the earth's crust according to the drilling marks of marine animals on the column. 2.

The speed and amplitude of tectonic movement are fast and slow, but most of them are long-term slow movements. For example, 40 billion years ago it was an ocean, but today it is. Since the Paleogene and Neogene, the average annual increase has been an average annual increase in the 70 years, and the rate of increase has been increasing in recent years.

In addition, the middle ridge of the ocean is also moving to both sides at a rate of 2 4 cm per year. The amplitude of tectonic motion (referring to the amount of displacement) varies with time and place. The amplitude of the motion is related to the direction and speed of the motion.

Regardless of vertical or horizontal movement, as long as the direction of motion remains the same, the longer the time, the greater the amplitude of motion, and the faster the speed at the same time, the greater the amplitude of motion. The Himalayas, for example, have been more than 10,000m since they began to rise. On the contrary, in areas like this, the thickness of the Paleogene and Quaternary sediments there has dropped by about 1,000 m.

The movement of the earth's crust is the frictional collision between plates, which can produce volcanic eruptions, tsunamis, etc.

Geological formations are created by the movement of the earth's crust. For example, faults. Fracture and so on.

Tectonic landforms are the landforms created by the movement of the earth's crust based on the human eye.

Tectonic movement, a geological point of view, is a subjective nature of speculation and speculation about the structure of the sea and land and the movement of the earth's crust.

The movement of the earth's crust refers to the movement of sea and land structures, which is objective.

Tectonic movements, which are in the crustal motion, must be in line with, and be subject to, and serve the movement of the earth's crust.

Answer]: bThe main forms of crustal movement are vertical (lifting) motion and horizontal motion. Among them, vertical motion refers to the movement of crustal material in the direction of the vertical geoid plane.

It is often manifested as a large area of rise or fall, resulting in changes in the elevation difference of terrain, such as changes in sea and land, changes in the source of mountain heights, etc. The ACD triatym is caused by the horizontal movement of the earth's crust.