Among critical writing dealing with the origins of land art, Rosalind Krauss’s essay ‘Sculpture in the Expanded Field’ is particularly interesting (it is reprinted in her stimulating collection The Originality of the Avant-Garde and Other Modernist Myths). She argues that for most of its history sculpture was site specific, but that increasingly Modernist sculpture (the kind of work made by artists like Brancusi and Caro) was site-less and self-referential, no longer directly connected to buildings or landscapes. Sculpture had become implicitly defined as not-landscape and not-architecture, but all this started to change in the late sixties when artists began to seek an expanded field of possibilities.
To describe these developments Krauss uses a structuralist diagram based on the Piaget group. Sculpture is in one corner, but there are three other options. The opposite of sculpture is art that is both landscape and architecture: site-constructions like Robert Smithson’s Partially Buried Woodshed (1970). Ian Hamilton Finlay’s garden Little Sparta would seem to fit this category (Krauss saw Japanese gardens as an example of non-Western art that is both architecture and landscape). The architecture but not-architecture category covers various kinds of interventions into real buildings - Gordon Matta-Clark’s work springs to mind. Then there is art that is both landscape and not-landscape, which Krauss identifies as the marked sites of land art, including the work of Richard Long. A work like Long’s Sahara Line (1988) can thus be seen as art in the landscape that is nevertheless, like sculpture, an autonomous art work separate from any landscape.