The Lost City - 1935 Serial Ep 03 Dagger Rock

The Lost City is an independently made 12 chapter science fiction film serial created and produced in 1935 by Sherman S. Krellberg and directed by Harry Revier.
Scientist Bruce Gordon comes to a secluded area in Africa after concluding that a series of electrically induced natural disasters had originated from in the area. There he finds the crazed Zolok, last of the Lemurians, in a secret complex inside a mountain.