Axis is a signifier in sculpture, and South African artist Bronwyn Katz has a history of making resolutely vertical sculptural pieces. Installed in the main gallery of her phonetically engaged exhibition “/ // ! ǂ” at Blank Projects are two dozen slender columns made of steel wool and cardboard, their gray surface covered with a weave of raspy copper mesh. Flanked by three flowing wire tapestries of variable lengths and widths, titled kx (i)–(iii) (2019), the vertical form of Katz’s enigmatic floor piece, x (2019), recalls her breakthrough BFA work, Ouma Grootjie [Grandma] (2015), a freestanding column made of gray bricks and green soap blocks that, still now, reads as steadfast exclamation mark from a year colonial statues were toppled in South Africa.

Katz, who graduated from the University of Cape Town in 2015 with an impressive cohort that included Simphiwe Ndzube and Siwa Mgoboza, has quickly distinguished herself with her coolly minimal abstract sculptures exploring social issues around land, homelessness, and belonging. A founding member of the all-women collective iQhiya, who participated in Documenta 14, Katz’s personal work has been widely exhibited too, notably in Dakar, Marrakesh, and Paris. The artist’s 2018 solo exhibition at the Palais de Tokyo featured a number of defiantly vertical pieces, including a fence-like structure made from mattress wire, a recurring material in Katz’s early work, as well as three pendulous stone forms that echoed the stubborn verticality of her student column.

“What then of horizontality?” asked critic Robert Pincus-Witten in Postminimalism (1977), his question a preface to detailing the “concerted assault on the axiomatic verticality of sculpture in favor of horizontality” in American art of the 1960s and ’70s. Although she was born in 1993—the same year Kendell Geers made and first exhibited his Carl Andre–inspired suspended brick installation Hanging Piece—Katz’s formally spare sculptures, often made of found materials, are part of this lineage of postminimalist work, when tradition had been toppled from its plinth. But let me not make a dogma of ancestries, or indeed verticality.

Arguably the most striking feature of Katz’s sculpture is her acute materialist sensibility. It is announced at the entrance to her exhibition with ore (2019), a wall-mounted piece composed of a grid display of 12 iron-ore pieces, each of the deep-purple rocks measuring roughly the size of a goose egg. The work invokes a recurring theme in her practice: land. Katz was born in Kimberley, the site of South Africa’s first colonial-era mining boom. The region around this city is also home to numerous petroglyphs, compelling figurative and abstract inscriptions on terrestrial rocks that collectively function as a codex for South Africa’s first people.

Similar to Walter Battiss, a pioneer abstract painter who spent the 1940s and ’50s scientifically cataloguing this earlier art, Katz’s exhibition looks to an ancestral past for vitality. Unlike Battiss, however, she interprets this inherited energy sonically rather than visually. The title of the show is a composite of four clicking consonants from Khoekhoe and other endangered indigenous languages. Working with sound artist Danielle Kyengo O’Neill, Katz produced a looped soundtrack that forms part of her columnar display. Alternating between strange glottal sounds and metallic clinking, this abstract soundtrack wraps the entire exhibition. It is like being immersed in an artisanal mine.

A smaller space at the rear of the gallery showcases four abstract sculptures made from corrugated iron and round steel. Each is named for a click consonant. // (2019) vaguely resembles a moth, its bent steel bars forming the antennae and the triangular-cut iron serving as improbable wings. More presciently, this quartet of rudimentary sculptures recalls Mozambique-born artist Ângela Ferreira’s sculpture series “Sites and Services” (1991–92), made of mild steel, PVC piping, cement, wood, and aluminum. Ferreira drew inspiration for this work from newly landscaped plots of land outside Cape Town equipped with basic service infrastructure. “Sites and Services” proposed a new and utterly enthralling abstract sculpture inspired by the post-apartheid landscape. Katz’s work presents a dynamic continuation of this liberated practice, one whose vitalities exceed a doctrinaire rehearsal of postminimalism.