Originally posted by dsmithhfx Frost heaves more likely.
I think we are talking about choice (D) All Of The Above.
Frost heaving is one of the active ingredients in Slope Creep (at least at my latitude), as is "over-steepening of slope" most often caused by water saturation during periods of heavy rainfall, which causes instability of the weaker soil layers. The weakest components are what determine how steep a land form can stand without slumping, sliding, or collapsing in a landslide. Also, the weight of the extra water in the soil is also crucial. This reminds me that the gravestones are considerably heavy in many cases and will affect the soil stability in their immediate area. And any kind of internal collapse (like the rotting casket) could cause problems nearby at the surface, too.
Mr. Pugh, my professor for "Geological Hazards" would be proud of me remembering all this stuff he showed my class on our field trips! But I see variations of those things on the landscapes around me all the time.