Real scientific results
The main surprise was that the earth crust turned out to be not a two-layer, as previously was thought. The subsurface rock was the same, but because of the depth and the associated pressure and the temperature the properties of ordinary granite had changed. Basalt, which was to be found, was never found.
Another surprise was that the temperature with depth rose more rapidly than it was expected.
A third surprise was the fact that with increasing depth, the subsurface rock became not more dense, but rather more porous. In numerous rock fractures there were aqueous salt solution circulating around (water at high pressure in a salt solution boils not at 100 degrees Celsius, but at much higher temperatures).
Drilling of Kola borehole was halted in 1994 at a depth of 12,262 m. The main thing is that scientists have been able to realize all the goals set for this project. Many scientific discoveries have been made that advanced the understanding of the scientific world about the structure and properties of the Earth’s interior.