Artnet Auctions’s fourth Abstracted sale is now open for bidding, presenting artworks from the 1940s to the modern day that explore and deconstruct the fundamentals of art in radical, inventive ways.

Long before Instagram’s developers were even born, Gianfranco Gorgoni made the abstract concept of land art accessible to audiences around the world. In the late 1960s and early 1970s, artists like ...