September 13, 2012 9:05
The search for the oldest section of the Earth's crust are not only the element of passion for sport in the sense as understood by scientists. Such studies provide a huge amount of valuable data for seismologists, paleobiology, and many others in the scientific community. Recently, scientists have identified the most ancient of the permanent seats of the world — it was rocky in the Negev desert in Israel.
The previous record for an antiquity is hydrochloric Plateau in the U.S. state of Nevada — according to experts, his age was estimated to be 500,000 years. So much time in the region had been no serious signs of seismic activity, and the only disruptive factor is water and wind. By about the same age, and attributed the Negev Desert, which occupies about 60 percent of the territory of Israel. However, research specialist in geomorphology Matmona Ari and his colleagues from the University of Jerusalem have shown that this estimate is wrong and the age of the Negev is 1.8 million years old, which is almost four times as much, writes sunhome.ru
To calculate this result, the scientists used a technique of radioactive analysis, examining the half-life of super-heavy isotopes of beryllium-10. This substance is found only rarely, so its detection in rocks and the possibility of dating with it were just what we needed for the expedition. Beryllium-10 can be produced only in the crust, and its condition indicates the date of formation of the tectonic plates.
"Since the formation of the desert is directly related to the age of its surface, we have long used for the calculations is the state of the upper layers. But it does not take into account the various anomalous emissions of rock to the surface, — says Ari Matmon. — In fact, in the desert with a very smooth surface, even wind can create serious erosion. These deserts can remain unchanged for millions of years, but before we knew it, and, accordingly, does not take into account. "
Ari Matmon sure that radioactive analysis will help identify other ancient desert land. So, for example, is subject to review dating Sahara and Arabian deserts. It is known that both education emerged in the last 10,000 years, but, at the same time, the age of the earth's surface under a layer of sand can be significantly longer.
One of the results of such checks can be a collection of evidence that will confirm or refute the theory that all naturally formed desert in the world (but not the ones that result from human activities) are located on the ancient site of the rocks, hundreds of thousands remain unchanged and even millions of years. Ari Matmon who spent years dating of geological formations on the rare earth isotopes, confident that at the end of the full range of research can make a world map of these ancient sites of the Earth and explore the reasons for their preservation.