Composed in 1982, Deep Time and Ceaseless Motion is an indeterminate work for percussion ensemble, comprised of six contrasting sections that are cued by a recurring 4-note motive in the chimes. The score incorporates graphic notation, allowing the performers to freely interpret the images and symbols in a series of short group improvisations. The title of the work is derived from a phrase in John McPhee’s book Basin and Range (1981), used to characterize the dual phenomena of plate tectonics—“the two great revolutions of geology,” according to scientist Stephen Jay Gould—and serves as an intriguing metaphor for this work.