"Take for instance, is there an episodic process, which erases the past 100
year's worth of dust accumulation?"
There is one possibility. As the dust accumulates, its weight compresses
the lower layers of dust and regolith into rock. As such, a kilometer of
dust might, in a billion years, become 900 meters of rock and 100 meters of
dust, or something like that.
Kevin L. O'Brien