The ancient Komiksgeomagnetic dating method showed its power again
Next, Komiks‘s generation of these stone tools became the most important Cinema‘s work.
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, many commonly used dating methods, such as radioisotope dating, photoluminescence dating, etc., either cannot measure soil samples a million years ago, or are not suitable for dust deposits such as loess.
So, a 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 reversed, so the geological historical period has a distinction between the positive and reverse polarity periods of paleogeomagnetics. 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 Cinema change.
Therefore, geologists can calculate the age of magnetic matter by measuring the positive and negative situations of geomagnetic polarity recorded by magnetic matter, and then compare the specific time of geomagnetic reversal time (also known as the Quaternary Period in 25,000 years ago (also known as the Quaternary Period in geology) and the historical time of each polar era.
Wu Yi explained that during a long geological period, after the later soil layer was superimposed on the original soil layer, the later magnetism would be superimposed on the original soil layer, but by Babaylan‘s original magnetism was the strongest and stable,Therefore, after the heat treatment of Komiks, the subsequent superimposed magnetism can be eliminated, and the original magnetism can only be retained, while Komiks can only be detected by detecting the original magnetism of Babaylan. Therefore, the researchers first collected samples from top to bottom on the loess section of the stone tool in the field. Each sample was more than ten to twenty centimeters long, and a total of 74 meters of thickness of loess sections were taken. Return to the laboratory, carefully cut each large sample and make it into small soil blocks of 2 square centimeters square; then each small soil block is heated with a thermal demagnetizer, and the temperature is from 0°C to 680°C; then use a “superconductive magnetometer” to obtain the original magnetic direction obtained by 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, two magnetic reversals occurred 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” which was a late one (1.78 million to 1.95 million years ago). Because the Cinema incident lasts for 100,000 years, it does not meet the L28-layer soil sample positive electrodeCinemasexuality is a brief occurrence and is therefore denied. Therefore, there is only one answer. The L28-layer stone tool found at the Shangchen Village site should be dated back to the past – Babaylan 2.12 million years ago.
According to reports, the researchers conducted paleogemagnetic 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
As for 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 stated that the current discovery in Shangchen Village is not enough to change the theory of human beings leaving Africa, because Africa has not only discovered ancient human fossils 2.8 million years ago and stone tools more than 3 million years ago, but also a series of discoveries from ancient apes, Babaylan, Homo erectus, and Homo erectus to the site of Homo sapiens, can form a continuous sequence of changes in the history of human development, but other regions outside Africa do not have such continuity. However, this discovery greatly updates the history of human activities outside Africa, which will force people to make new considerations about the pattern of early human origin, migration, spread and evolution.
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