In July a group of scientists from Moscow, St. Petersburg, and the Tuvan Institute of Complex Natural Resource Development-- Siberian branch of the Russian Academy of Sciences will carry out geological research in Mongolia. Doctor of Geological Sciences, Vladimir Lebedev, and candidate of Geological Sciences, Amina Sugorakova, are supervising the work of this expedition. The group will study the age and a sequence of the formation of magmatic, ophiolite complexes of the Caledonian and Herzin zones. It should be noticed that before perestroika such work was conducted by permanent Soviet-Mongolian geological expeditions, which has subsequently been broken up. Now there is a restoration of this work within the framework of the new Russian-Mongolian expedition, which will also occur on a permanent basis. Specifying the purpose of research, Amina Sugorakova has noticed that based on the results of this expedition, the revisions of many established positions of the geological history of the Earth is probable, including that of Central Asia. It became possible due to the modern level of geochronological and isotope-chemical research.