Final answer:
Alfred Wegener, a German scientist, originally proposed the idea of continental drift and the supercontinent named Pangaea. The Supercontinent Cycle is a concept developed from his foundational work, which gained acceptance with the later validation of plate tectonics in the scientific community.
Step-by-step explanation:
The theorist who proposed the concept of the Supercontinent Cycle was a German scientist named Alfred Wegener. Wegener, initially an astronomer, shifted his focus towards earth sciences and meteorology. His fascination with the arrangement of continents led to his continental drift hypothesis, presented in 1912, where he suggested that continents had once been joined together in a supercontinent he named Pangaea. However, the concept of the Supercontinent Cycle, which is the periodic assembly and fragmentation of supercontinents, including Pangaea, was a development that came about with further advances in earth sciences, building upon Wegener's foundational ideas.Wegener's continental drift hypothesis was revolutionary, as he proposed that the continents were not static but moved across the Earth's surface over time. He used evidence such as the jigsaw fit of continents, matching fossils, mountain ranges, and paleoclimatic data to support his theory. It was only with subsequent research in geology and oceanography, and the eventual acceptance of plate tectonics in the 1960s, that mechanisms for such movements were understood, vindicating Wegener's early 20th-century proposals.In conclusion, while Alfred Wegener proposed the idea of continental drift and the formation of Pangaea, the theory of periodic supercontinent assembly and breakup, referred to as the Supercontinent Cycle, was built upon his early work and required further developments in geological sciences to be fully conceptualized and accepted.