Final answer:
The accepted theory for the movement of plates in the 1960s was plate tectonics, developed by Harry Hess. It explains how the Earth's lithosphere is divided into plates that constantly move and interact with each other.
Step-by-step explanation:
The accepted theory that explained the movement of plates in the 1960s is known as plate tectonics. This theory was developed by geologist Harry Hess, and it was supported by a greater understanding of the seafloor and oceanic features.
Plate tectonics explains how the Earth's lithosphere is divided into several large and small plates that constantly move and interact with each other. These plates can collide (convergent boundary), move apart (divergent boundary), or slide past each other (transform boundary).
One important piece of evidence for plate tectonics is seafloor spreading, which occurs at mid-ocean ridges where new crust is being formed. Hess's theory helped provide a comprehensive explanation for various geological phenomena, such as earthquakes, volcanic activity, and the distribution of mountains and ocean trenches.
Learn more about Plate tectonics