The mass movement in which materials move as one large mass is called a slide.

Here's why:

* Slide: In a slide, a coherent block of material moves downslope along a defined surface. This movement can be very rapid, causing significant damage. Examples include landslides, rock slides, and debris slides.

Here are other types of mass movements, each with its own characteristics:

* Flow: Materials move as a viscous fluid, like a thick mud. Examples include mudflows and debris flows.

* Creep: Slow, gradual movement of soil or rock, often caused by freeze-thaw cycles.

* Fall: Individual rocks or blocks of material break off and fall down a slope, often triggered by gravity or erosion.

Let me know if you have any other questions about mass movements!