The beginning of the twentieth century marked the need to create an Argentine Geological Survey to study the country's potential in resources such as minerals, water, coal, and oil. Eng. Enrique M. Hermitte was put in charge of the new Division of Mines, Geology and Hydrology in 1904. Hermitte, in collaboration with Bodenbender, hired young German graduates with excellent recommendations to create a good Geology department. This was put in charge of Hans Keidel, a prestigious young geologist with a good track record who, during his twenty years as head of geology, managed to form a team of almost 15 German geologists who traveled the country from Jujuy to Tierra del Fuego. Important regional studies were carried out, with the survey of precise maps in the Puna, the Sierras Pampeanas, the Cordillera Oriental, and the Sierras Subandinas. These maps and their corresponding descriptions changed the geological knowledge of the country and contributed to the search for underground water. Numerous perforations were carried out to supply drinking water to localities in the interior producing basic and indispensable geological knowledge of the country. The new data allowed the evaluation of numerous manifestations of coal and other minerals. Various areas were incorporated into the geological knowledge, especially those of the new hydrocarbon basins of central Patagonia and Neuquén. The studies were successful and allowed a new vision of the regional geology of large sectors of the national territory in a few years.