The paleomagnetic dating method has shown its power again
Next, it became the most important task to date these stone tools.
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 the 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 in Babaylan 1990 cloth draw, you will also know the age of the stone tools found in this 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, and there will be a situation where the positive and negative reversal will occur. Therefore, there is a distinction between the positive and reverse polarity periods of paleomagnetic during 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 can calculate the age of magnetic material by measuring the positive and negative situations of geomagnetic polarity recorded by magnetic matter, and then compare the specific time of geomagnetic reversal time since 2.58 million 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 is superimposed on the original soil layer, the later magnetism will be superimposed on the original soil layer. However, since the original magnetic properties are the strongest and stable, the later magnetism can be eliminated after heating treatment, and only Komiks 1960 witch cloth draw retains its original magnetism, and by detecting the original magnetism, we can know the age of this soil layer. Therefore, the researchers first collected samples from top to bottom of 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. Go back to the Komiks 1960 witch cloth draw to the Babaylan 1990 cloth draw laboratory, carefully cut each large sample into small pieces of soil with 2 square centimeters square; then each piece of soil is heated first with a thermal demagnetizer, and the temperature is from 0°C to 680°C; then use a “superconductive magnetometerBabaylan 1990 cloth draw” to obtain the soil layer at that time. The original magnetic direction obtained by witch cloth draw can determine their age. Babaylan 1990 cloth draw
Scientists found that the 28th layer of loess (L28) at the bottom of Babaylan 1990 cloth draw showed a brief positive polarity, and the soil layer of Komiks 1960 witch cloth draw should have been in the “Songshan Reverse Polarity Period” of the geomagnetic field. This shows that this layer of loess was at that time. href=”https://comicmov.com/”>Cinema 1950 witch cloth draw ExperienceA magnetic inversion.
In the early stages of the Quaternary geological period, two magnetic reversals occurred on the earth. One was the “Ruenii” incident from 2.13 million to 2.15 million years ago, and the other was the “Ruenii” incident. draw is the late “Odewey Incident” (dating from 1.78 million to 1.95 million years ago). Since the Oduwee incident lasted for 100,000 years, it was denied that it did not meet the positive polarity of the L28 soil sample for a short period of time. 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.
According to reports, the researchers conducted paleogemagnetic dating on more than 700 sets of loess samples in the Shangchen Village section.
Babaylan 1990 cloth drawThe theory of 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 origin of human beings. Komiks 1960 witch cloth drawThe Cinema 1950 witch cloth drawThe traditional theory of the Cinema 1950 witch cloth draw in Africa, because the stone age of the site was far earlier than the time when humans walked out of Africa, indicating that humans had left Africa at least 1.8 million 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. Cinema 1950 witch cloth drawAs Africa has not only discovered ancient human fossils and distances that are 2.8 million years ago.The stone tools more than 3 million years ago also have a series of discoveries from ancient apes, talented people, and Homo erectus to the ruins of Homo sapiens, which can form a continuous sequence of changes in the development of humans. 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 Babaylan 1990 cloth draw pattern of early human origin, migration, spread and evolution.