Layers of stone built up into a form like a giant pine cone on an Iowa prairie. Polar snow blocks constructed into massive upright circles. A string of hazel leaves joined with thorns floated on a shallow French river.
Natural structure is the preoccupation of the English sculptor (and photographer) Andy Goldsworthy. His structures are often on the edge of disintegration or natural change. Appearing and disappearing, they would in the past have been considered too fragile to be acceptable as "sculpture."
Fascinatingly, Goldsworthy (one of several similarly motivated sculptors) proves that sculpture, specific to a place and time, may epitomize or even celebrate transience. Endless durability is not an aesthetic given.
Sculpture for centuries was tied to the idea of "memorial," meant to counter the mournful brevity of human life. (Painting and photography far more easily embraced impermanence.)
Goldsworthy's sculptures are more like nature. They do not have to withstand time and tide. They may, in fact, be more vivid or memorable because they do not last.
An ambitious trans-US project, in which Goldsworthy has conducted a virtual dialogue with himself about sculptural permanence and impermanence, is the subject of "Three Cairns," an exhibition at the Des Moines Art Center (until Oct. 13).
"Six Cairns" would have come closer. At this museum and, later, two others (in San Diego and Purchase, N.Y.) the sculptor has made "permanent" cairns of Iowa limestone. The Gaelic-derived word "cairn" signifies a stone pile that is a marker for travelers, or, significantly, a memorial. He also made, as recorded in his seductive large-scale color photographs, three "temporary" cairns on East and West Coast beaches and on a Midwestern prairie. The West Coast cairn was destroyed by the first tide to engulf it. The East Coast cairn withstood tidal advance and retreat for two weeks before succumbing. The Midwestern cairn still stands so far. The three museum cairns, though mortarless, are there forever.
Or are they?