Answer:
It was generally believed that mountains were produced by vertical forces
Step-by-step explanation:
The main view of the world worked geologically prior to the 1960s was that the mountains were formed by the vertical forces of nature.
The early people prior to 1960s believed in many different natural phenomenons and they give their own reasons for their occurrence. But later many researchers and geophysicists studied the formation of the earth and came with possible answers to these questions.
Thus the answer is
" It was generally believed that mountains were produced by vertical forces."