Generally, we hit rock after drilling to a depth in any place. The depth varies with places. What is the situation for mountains? Do mountains start from the core of Earth?
Answers (1)
People have dug mine shafts a thousand or so feet, and drilled wells a few thousand feet. One well in Russia was seven miles deep, just to see what was there. (Search for "kola borehole".) Oil company explorers have used dynamite to calculate images a few thousand feet below the surface. Earthquakes have been monitored in the same way to make images a little deeper. But we still have no idea what lies more than a couple of miles down. Only guesses.