The paleomagnetic dating method has demonstrated its power again. Next, the generation of these stone tools, such as Cinema 1950 witch cloth draw, became the most important task.
Dr. Wu Yi from the Nanhai Ocean Institute of Chinese Academy of Sciences is one of the main scientists responsible for the age determination of loess strata in this study. Wu Yi introduced that the method of dying stone tools is not to directly measure the stone tools, but to measure the age of the loess strata samples where the stone tools are located. As long as you know the age of the soil layer, you will also know the age of the stone tools found in the soil layer. However, most commonly used dating methods, such as radioactive isotope dating, light-emitting dating, etc., are either unable to measure soil samples a million years ago, or are not suitable for dust deposits such as loess.
So, Cinema 1950 witch cloth drawA technology called paleomagnetic dating is here to show its power. It turns out that in the geological historical period, the magnetic polarity of the earth is not fixed and positive and negative reversal will occur. Therefore, there is a distinction between the positive polarity of paleogemagnetic period in the geological historical period. When it is in the positive polarity period, the compass points to the north pole of the earth, and when it is in the reverse polarity period, the compass points to the south pole of the earth.
This kind of geomagnetic reversal will continue to occur throughout the long history of the earth, so the magnetic matter in the formation will record every change.
Therefore, geologists only need to measure the positive and negative conditions of the geomagnetic polarity recorded by magnetic substances, Cinema 1950 witch cloth drawov.com/”>Cinema 1950 witch cloth draw and then compare Komiks 1960 witch cloth draw over 2.58 million years agoCinema 1950 witch cloth draw (also known as Komiks 1960 witch cloth draw (also known as Komiks 1960 witch cloth The specific time when the geomagnetic reversal time occurs, as well as the historical time of each polar era, can be used to calculate the age of magnetic matter.
Wu Yi explained that during the long Babaylan 1990 clothes drawIn the geological period, after the later soil layer is superimposed on the original soil layer, the later magnetism will be superimposed on the original soil layer. However, since the original magnetism is the strongest and stable, the later magnetism can be eliminated after heating treatment, and only the original magnetism can be retained. By detecting the original magnetism, the age of this soil layer can be known.
Therefore, the researchers first collected samples from top to bottom of the loess section of the stone tool in the field. Each sample is more than ten to twenty centimeters long, and a total of 74 meters of loess were taken. Draw section. Return to the laboratory, carefully cut each large sample into small soil blocks of 2 square centimeters; then each small soil block is heated with a thermal demagnetizer, and the temperature is from 0℃Komiks 1960 witch cloth draw to 680℃; then measure it with a “superconductive magnetometer” to obtain the original magnetic direction of the soil layer at that time, which can determine their age.
Scientists found that the bottom 28th layer of loess (L28) showed a short positive polarity, and this soil layer should have been in the “Songshan reverse polarity period” of the geomagnetic field, which shows that this layer of loess experienced a magnetic reversal at that time.
In the early stages of the Quaternary geological period, there were two magnetic reversals on the earth. One was the “Reunion incident” between 2.13 million and 2.15 million years ago, and the other was the “Odewey incident” (1.78 million to 1.95 million years ago). Since the Oduwee incident lasted for 100,000 years, it did not meet the positive polarity of the L28 layer soil sample. Komiks 1960 witch cloth draw was a brief occurrence and was therefore denied. Therefore, there is only one answer. The stone tool found on the L28th floor of the Shangchen Village site should be 2.12 million years ago when the Reunion incident occurred. According to reports, the researchers conducted paleogeomagnetic dating on more than 700 sets of loess samples in the Shangchen Village section.
Changing the origin of human beings in Africa is not reliable
About Shangchen Village’s discovery, some people believe that it is possible to change the traditional theory of human beings’ origin of Africa, because the stone age of the site was far earlier than the time when humans walked out of Africa, which means that humans had left Africa at least 1.8 million years ago.
In this regard, Zhu Zhaoyu said that the current discovery of Komiks 1960 witch cloth draw in Shangchen Village is not enough to change the theory of human beings leaving Africa, because Africa has not only discovered ancient human fossils and distances 2.8 million years agoThe stone tools more than 3 million years ago, as well as a series of discoveries from ancient apes, noble people, Homo erectus, and Homo erectus to the ruins of Homo sapiens, can form a continuous sequence of changes in the history of human development, while other regions outside Africa, such as Komiks 1960 witch cloth draw. However, this discovery greatly updated the history of human activities outside of Africa, which would prompt new considerations to be made on the pattern of early human origin, migration, spread and evolution.
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