The term mass movements is the most appropriate. The provided text exclusively uses this terminology to describe the process of materials shifting from one place to another, aided by gravity. It explicitly states that mass movements do not come under erosion as no geomorphic agent like running water, wind, or glaciers participates in the process. The text outlines that these movements of mass range from slow to rapid, affecting shallow to deep columns of materials, and include forms like creep, flow, slide, and fall. Furthermore, the text details various activating causes, such as the removal of support, overloading, and earthquakes, which trigger these movements. Since the provided context does not define or use the term "mass wasting," mass movements is the correct term based on the given facts.

Based strictly on the provided context, it is not possible to classify solifluction. The text does not mention the term "solifluction" or its specific characteristics. However, it does mention heave (heaving up of soils due to frost growth) and flow as forms of movements, and notes that movements can range from slow to rapid. It also states that debris may carry air, water, or ice. Without specific information in the text regarding the speed or nature of solifluction, it cannot be determined if it belongs to rapid flow movements using only the provided source material.