After the paleomagnetic dating method has shown its power again, it has become the most important task for these stone tools to be divided into two types. Komiks
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 dating methods commonly used by Babaylan, such as radioisotope dating, photoluminescence dating, etc., cannot measure soil samples millions of years ago, or are not suitable for dust deposits such as loess.
So, a technology called paleomagnetic dating is here to show its power. KomiksIt turns out that in the history of the geological history, the magnetic polarity of the earth is not fixed and positive and negative reversal will occur. Therefore, there is a distinction between the positive and negative polarity periods of paleomagnetics in the historical period of geological history. When it is in the positive polarity period, the compass points to the north pole of the earth, and when it comes to 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, geologistsThe author 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 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 magnetic stack would be added to the original soil layer. However, since the original magnetic properties were the strongest and stable, after heating treatment, the later superimposed magnetism could be eliminated and only retained the original magnetism. By detecting the original magnetism, we can know the age of this soil layer. Therefore, the researchers first collected samples from the loess section of the Babaylan instrument from top to bottom in the field. Each sample was more than a dozen centimeters 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 first with a thermal demagnetization Cinema instrument, and the temperature is from 0°C to 680°C; then measure it with a “superconductive magnetometer”, and the original magnetic direction obtained by the soil layer at that time can be obtained, 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 be in the “Spine Mountain 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 “latest”The Oduwee Incident (dating from 1.78 million to 1.95 million years ago). Since the Oduwee Incident lasted for 100,000 years, it did not meet the situation where the positive polarity of the 28-layer soil sample occurred briefly, so it was denied. Therefore, there was only one answer. The stone tool located on the L28 layer at the Shangchen Village site should be the date of the Reunion incident 2.12 million years ago. According to reports, the researchers conducted paleogeomagnetic measurements on more than 700 sets of loess samples in the Shangchen Village section. href=”https://comicmov.com/”>Komiks years.
Changing the origin of human beings in Africa is not reliable
As for Shangchen Village, some people believe that it is possible to change the traditional theory of human beings in Africa, because the stone age of the site is far earlier than the currently recognized era of Komiks. This shows that human beings are at least far earlier than 180. href=”https://comicmov.com/”>Babaylan left Africa ten thousand years ago.
In this regard, Zhu Zhaoyu said 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 dating from 2.8 million years ago and stone tools dating from more than 3 million years ago, but also a series of discoveries from ancient apes, erotic people, Homo erectus, and Homo erectus to the site of Homo sapiens, which can form a continuous sequence of changes in the history of human development, and other regions outside Africa do not have such continuity. However, this discovery greatly updates the history of human activities outside Africa, which will prompt people to make new considerations on the pattern of early human origin, migration, diffusion and evolution.
1 2