On the cause of continental breakup: A simple analysis in terms of driving mechanisms of plate tectonics and mantle plumes

摘要

Earth's continents can come together to form supercontinents and the supercontinents can break apart into fragments of varying size scattering around the globe through a hypothetical process called continental drift. The continental drift hypothesis had survived after 60 years debate and evolved into the powerful theory of plate tectonics with unquestionable and irrefutable lines of evidence. This narrative statement is familiar and acceptable to everyone in the scientific community, but scientists differ when talking about the cause of continental breakup. Some advocate mantle plumes, especially superplumes, as the cause ("bottom up"), whereas others emphasize plate tectonics to be the cause ("top down") and still some believe both are needed. In this short paper, I do not wish to enter the debate, but offer a readily understandable geological analysis on the likely driving mechanisms of plate tectonics and mantle plumes, which leads to the conclusion that continental breakup is a straightforward consequence of plate tectonics without requiring mantle plumes. Mantle plumes, if needed, may be of help at the early rifting stage, but cannot lead to complete breakup, la alone to drive long distance dispersal of broken continents. Superplumes invoked by many do not exist. The debate may continue, but I encourage enthusiastic debaters to consider these straightforward concepts and principles of geology and physics given in this objective analysis.