Generally speaking, people from far corners of the world have never heard about a little country named Estonia, or if they have, it is only for a few things. But doctoral student Juan David Solano Acosta knew exactly where he was coming: "I am interested in politics and economics, and Estonia's goal of being Europe's own Silicon Valley intrigued me a lot," the young man stated, "especially knowing that it is a country with such a tiny population. But I like it here and I have adapted," adds Juan, who comes from a country with 49 million inhabitants.

The vocation to study the Earth's crust is literally in Juan's blood, because his father was also a geologist. "I have wanted to study natural sciences since I was a child, and I discovered that geology fulfills my expectations, because here, in addition to doing research, I can be useful to society in a very important topic - the world's economy and the development of societies depend on mineral reserves," he said. Juan wants his work to have a wider meaning, therefore he focused on economic geology and the study of rocks locatedin deeper layers of Eartg. "We are talking about rocks from the Precambrian period, i.e. billions of years old. Exploring them is a real adventure for most geologists,” explains Juan.

Geology goes deeper and deeper

His doctoral supervisor, Rutt Hints, a senior researcher at the TalTech Institute of Geology, confirms that Juan has chosen an exciting topic. "He mainly studies the basic metal ores of northeast Estonia. They are considerably older than the sedimentary bedrock consisting of limestone, clay, and sandstone." According to Hints, we have to go back in time 1.9-1.5 billion years, when the earth's crust in our region was just forming and the area of ​​Estonia was very active tectonically. The rocks in the ground, which PhD student Juan is currently studying, date from that time.

This layers can be studied with the help of drill cores, which lift samples off the ground. "In the case of Estonia, it has been known for a long time that there are zinc and lead ores in our bedrock, as wells as copper deposits," Hints points out. According to Hints, the most well-known deposit of this era is the Jõhvi iron ore, although recent research have also revealed Estonia's first gold ores.

In addition to crustal field research in northeast Estonia, Juan compares the obtained data with those of the Bergslagen microcontinent in central Sweden. Scientists have come to the conclusion that Estonia has a geological similarity to this region, although our landscape looks completely different compared to the skerries of crystalline rocks that surround Stockholm. "In Estonia the Precambrian rocks are not exposed and they are deep in the ground, to study them you have to go after them figuratively speaking. However in Colombia, for example, rocks of the same age can be seen in several natural environments, such as jungles, deserts, forests, mountains, volcanoes. Once the research material has been obtained, the laboratory research methods of different countries can be quite similar."

Rutt Hints calls Juan's research the geology of the future: "The number of high-concentration ore deposits near the surface is decreasing, they are being depleted. We have to go deeper for ores, and therefore it is very important that such research is already underway in Estonia. They will not give a tangible result in the next ten years. However, talking about current students, it is possible that during their working years they will be able to see how deeper layers of our land will be explored,"

You have to know where to look

Besides the analysis of drill core samples, there are increasingly better and more accurate geophysical research methods based on data from satellites and other remote sensing devices and magnetic field studies. "If we have data, we can draw conclusions about the Estonian crust by modeling it," confirms Hints, who says that it is important to understand the structure of the Estonian crust both for Juan's doctoral thesis and for shaping Estonia's future mineral policy. "Based on this, you can make further reasonable assumptions about where to go and search ore."

Deep crustal research is a priority across Europe. "With today's technical equipment, we can mine up to a depth of about 3 kilometers, in certain places even further, where the underground temperature rise is not so high. Yet our knowledge about the Earth's crust is often limited to the first kilometer, in Estonia even only the first few hundred meters," says Rutt Hints, "What does that mean? That we still have well over two kilometers of space to explore."

The TalTech Institute of Geology is part of the Faculty of Science and combines natural sciences, engineering and IT. Graduates of the Institute's new bachelor degree "Earth systems, climate and technologies" can become green innovation and earth crust engineers, climate scientists, marine researchers, geologists, data analysts or some other science specialists that meet the demands of the future economy.

Learn more:
TalTech Institute of Geology
+372 5121131
geo@taltech.ee