Geologists will learn how volcanoes produce gold

Geologists will learn how volcanoes produce gold

TSU geologists have returned from an expedition to Yakutia, where they will conduct research to find new gold deposits. The geologists will be able to identify promising areas for mining by studying large igneous provinces (LIPs) formed as a result of magmatic processes hundreds of millions of years ago. The formation of deposits of gold, nickel, copper, platinum, and diamonds is associated with them.

- One of the main tasks of the project is to study the influence of LIPs on the appearance of ores in the so-called zones of disagreement. The research site is one of the largest gold-bearing provinces - Aldan, - says Platon Tishin, the head of the expedition, Dean of the Faculty of Geology and Geography. - In this province, there are such well-known deposits as Lebedinovskoye, Kurinakhskoye, and the Tabornoye and Gross deposits, which were discovered not so long ago in the western part of the Aldan Shield. In 2017, a new large manifestation of gold was discovered on the flank of these places, but its borders are not clear yet and reserves have not been calculated.

The TSU geologists’ research will help to identify a promising area for mining. The object of their study is the zone of disagreement – places where the composition of rocks changes dramatically. Here hundreds of millions of years ago, when LIPs were formed by eruptions of ancient volcanoes and other magmatic processes, intense heating of the earth's crust and circulation of chemical solutions containing gold took place. These solutions rose to the Earth's surface and accumulated at the boundaries of granites and sandstones, where minerals were formed, including major gold deposits.

When geologists studied deposits in Yakutia, they noticed that there are signs of several erupted provinces. During the expedition, staff of the Laboratory of Geochronology and Geodynamics and students of the Faculty of Geology and Geography took samples of ore and igneous rocks. The absolute age of these samples will be determined using a unique installation for conducting radioisotope dating that can date objects up to four billion years old.

- There is a connection between the age of LIPs and the formation of a field,- explains Platon Tishin. - For example, diamond deposits appeared where LIPs total about 300 million years. We are looking for a similar pattern in relation to gold deposits. The Aldan Shield for us is an experimental site where we collect information that in the future will help significantly reduce the time and territory of the search for new gold deposits.

Geologists will present the result of the project at the end of 2019. Siberia has one of the largest large erupted provinces in the world - the Siberian traps. The study of LIPs will clarify the potential of Siberian deposits and find new areas promising for the extraction of valuable minerals and non-ferrous and noble metals.