1. is the key to understand the genesis of special sedimentary layers on key stratigraphic boundaries in sedimentary circles.
Since Alvarez discovered a special clay deposit on the Cretaceous/Paleogene boundary in Italy in 1979, he has successively discovered clay deposits on the Precambrian/Cambrian boundary (Zhang Qinwen et al.,1984; Xu Jinghua et al, 1986) and Permian/Triassic (sun yiyin et al,1984; Xu et al., 1985, Chai Zhifang et al., 1986). The content of iridium (Ir) in these clay layers is extremely high, while the content of iridium (Ir) on the earth is very low. 1980, Luce Alvarez and his colleagues put forward the asteroid collision theory to explain the origin of clay layer on the Cretaceous/Paleogene boundary and the extinction of biota on the boundary. Since then, earth scientists have become more and more interested in the consequences of meteorites hitting the earth.
2. It is the driving force for the formation of some basins on the earth's surface.
A crater (a larger crater is also called a crater) is an annular crater formed when a meteorite hits the surface of a planet, satellite, asteroid or other celestial body (figure11-1).
Fig.11-1/schematic diagram of crater formation process.
In the craters formed by the impact of meteorites on the earth, they are often filled with water to form impact lakes, and lacustrine deposits appear in the lakes. Therefore, the driving force for the formation of circular pits and craters on the surface of the earth, the moon, mercury, Mars and their satellites is the cause of meteorite impact. At the same time, the impact of huge meteorites in this process can provide valuable information for the study of the formation of the earth and other planets, the influence of primitive heat and the change of rotation axis, as well as the study of magmatic activity, catastrophic events and planetary evolution.
3. The dynamic source of plate movement on the earth's surface is expounded.
Plate tectonics is a new global tectonic theory put forward in 1960s. From 65438 to 0968, according to various data, Le Pixiong first divided the global lithosphere into six plates, namely, the Pacific plate, the Eurasian plate, the Indo-Australian plate, the African plate, the American plate and the Antarctic plate. Except for the Pacific plate, which is almost entirely ocean, the other five plates have large areas of land and oceans. With the development of research work, some people further divide many small plates into large plates. For example, the American plate is divided into North America plate and South America plate, the East Pacific plate is divided into one plate, and the Eurasian plate is divided into Southeast Asia plate and small plates such as the Philippines, Arabia, Turkey and Aegean Sea.
The existing research results show that plate movement is closely related to asteroid impact on the earth. It is the high-energy collision between asteroids and the earth that causes the crust to rupture and form a plate, which makes the plate drift on the Si-Mg layer.
4. Understand the reasons for the extinction of many earth creatures, including all dinosaurs.
During the evolution of the earth's sedimentary circle, there have been many extinction events. Among them, the extinction of dinosaurs occurred on the earth 65Ma ago, which is thought to be due to the impact of a huge asteroid or comet on the earth (an asteroid hit the Yucatan Peninsula in Mexico 65Ma ago). The recent computer simulation in the United States also illustrates this point. It was not until 12 years ago that this huge crater was discovered. From 200 1 to 65438+February, the geographical research center in Potsdam, Germany started the research in this field. This celestial body may have hit a crack thousands of meters deep on the earth's surface with the impact force equivalent to 654.38+000 billion atomic bombs. The fragments of the impact scattered one after another, causing strong earthquakes, tsunamis, floods and fires. A large amount of dust and gas produced by this collision mixed into the atmosphere, which covered the sky and made the climate abnormal. First the fire, then the glacier, then the unbearable heat. This ecological disaster led to the extinction of animals and plants, including dinosaurs.
5. Enrich the content and theory of sedimentology.
Incorporating meteorites falling from outer space into the earth's surface and craters formed by meteorites hitting the earth into the research field of sedimentology will further enrich the research content of sedimentology and deepen its theoretical system.
6. It helps to understand the origin of life on earth.
According to the Russian Interfax news agency on March 3 1, 2065438, Yevgeny Dmitrieff, a scientist at the Planetary Protection Center in Lavochkin, Russia, announced that fossils of biological debris had been found in meteorites that fell in Tunguska and Tulan, Si Nuo, Russia. He believes that these biological fossil fragments are strong evidence to prove the existence of alien life. These special "bone" fragments are so tiny that they can only be seen under a microscope. Dmitrieff thinks they may come from the moons of Jupiter or other giant planets.
By analyzing samples of meteorites from different places, Dmitrieff came to the conclusion that there may have been or still be an ocean composed of water on the planet that gave birth to these meteorites. If his conclusion is finally confirmed, then the earliest life form on the earth is likely to come from somewhere outside the earth (according to Tencent Technology on March 319: 57,2065438, Russian scientists said: evidence to prove the existence of extraterrestrial life has been found) (Figure1/KLOC-0)
In a word, the study of meteorites and craters is of great scientific significance for discussing the formation and evolution of the earth, the changes of paleoclimate, paleoenvironment and paleontology, diagenesis and mineralization. Some well-preserved craters have been developed into natural science museums, world natural heritage sites and tourist attractions because of their special scientific connotations and natural landscapes. Therefore, deepening the study of meteorites is not only an important task of sedimentology, but also one of the important tasks of regional science. The research results have important theoretical significance and practical value.
Figure 1 1- 12 contains meteorite fragments suspected of extraterrestrial remains.
Figure 1 1- 13 Skeletal fragments of suspected alien life seen under the microscope.