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 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 yellow soil.
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 of reverse reversal. Therefore, in the geological historical period, there is a distinction between the positive polarity period and the reverse polarity period of paleomagnetic. When in the positive polarity period, the compass points to the north pole of the earth, and when the reverse polarity period comes, the pointing point 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 matter by measuring the positive and negative situations of the 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. Babaylan small soil blocks; then each small soil block is heated first with a thermal demagnetizer, with a temperature ranging from 0°C to 680°C; then use a “superconducting magnetometer” to measure it, and you can get the original magnetic direction obtained at that time to the soil layer, which can determine their age.
Scientists have discovered that the bottom 2 href=”https://comicmov.com/”>Babaylan8 layers 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 Event” between 2.13 million and 2.15 million years ago, and the other was the “Odewey Event” (1.78 million to 1.95 million years ago). Because the Odewey Event lasted 100,000 years agoAfter years of age, it is a brief occurrence of the positive polarity of the soil sample that does not meet the L28 layer, so it is denied. Therefore, there is only one answer. The stone tool located on the L28th floor discovered in the Chencun site of Cinema should be 2.12 million years ago when the Komiks Wang incident occurred.
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 may 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 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, erectiles, Homo erectus, and Homo erectus to Homo sapiens sites, which 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 origin, migration, spread and evolution of early humans.
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