Information: - Spiral Jetty is an earthwork sculpture constructed in April 1970 that is considered to be the central work of American sculptor Robert Smithson . Smithson documented the construction of the sculpture in a 32 - minute color film also titled Spiral Jetty . Built on the northeastern shore of the Great Salt Lake near Rozel Point in Utah entirely of mud , salt crystals , basalt rocks and water , Spiral Jetty forms a 1,500 - foot - long ( 460 m ) , 15 - foot - wide ( 4.6 m ) counterclockwise coil jutting from the shore of the lake . The water level of the lake varies with precipitation in the mountains surrounding the area , revealing the jetty in times of drought and submerging it during times of normal precipitation . Originally black basalt rock against ruddy water , Spiral Jetty is now largely white against pink due to salt encrustation . Since the initial construction of Spiral Jetty , those interested in its fate have dealt with questions of proposed changes in land use in the area surrounding the sculpture and of the proper amount of preservation , if any . - Land art, earthworks (coined by Robert Smithson), or Earth art is an art movement in which landscape and the work of art are inextricably linked. It is also an art form that is created in nature, using natural materials such as soil, rock (bed rock, boulders, stones), organic media (logs, branches, leaves), and water with introduced materials such as concrete, metal, asphalt, or mineral pigments. Sculptures are not placed in the landscape, rather, the landscape is the means of their creation. Often earth moving equipment is involved. The works frequently exist in the open, located well away from civilization, left to change and erode under natural conditions. Many of the first works, created in the deserts of Nevada, New Mexico, Utah or Arizona were ephemeral in nature and now only exist as video recordings or photographic documents. They also pioneered a category of art called site-specific sculpture, designed for a particular outdoor location. - Robert Smithson (January 2, 1938 July 20, 1973) was an American artist famous for his use of photography in relation to sculpture and land art. After reading the paragraphs above, we are interested in knowing the entity with which 'spiral jetty' exhibits the relationship of 'genre'. Find the answer from the choices below. Choices: - art - land art - photography - rock
A:
land art