In two riveting, wildly different shows this month, one artist known for sculpture makes a jump to wall pieces while another artist known for wall pieces leaps onto the floor with a haunting series of sculptures. First, at Laura Russo, Mel Katz's Anodized Aluminum departs from his well-known metal sculptures and essays a suite of jaunty compositions fabricated from anodized aluminum. He makes the transition from floor to wall with wit and finesse, employing the same biomorphic shapes he's explored over his long career. Now more than ever, Katz seems to be channeling late-career Matisse, when the old master abandoned traditional painting in favor of buoyant gouache cutouts. Katz's Tapestry and Gold seem to nod to Matisse's curling, unfurling L'escargot, while his In Orbit nods to Matisse's The Sorrows of the King. With this dynamic, upbeat show, Katz proves that after nearly 50 years of exhibiting, he's an artist at the top of his form.

Meanwhile, at Elizabeth Leach, Joe Thurston branches off in new directions with the somber, masterly installation, Nothing Leading Anywhere Any More Except to Nothing. The show's existentialist title betrays its contemplative emotional tenor. Laid out in a maze of 35 wooden sculptures, the exhibition invites viewers to navigate through the rectangular monoliths, which Thurston calls "containers." Intricately constructed despite their rough-hewn appearance, they are covered in brown paint and black drips. They look like storage crates in Charles Foster Kane's warehouse, or oversized tombstones. In fact, each sculpture is a kind of tomb. Inside each, the artist has sealed an item of personal significance to him: a braid of hair, a pair of reading glasses, a plastic Champagne flute and a child's signet ring. The viewer is left to wonder what stories these trinkets tell. It is an act of detachment—a lightening of the load—to entomb, and offer for sale in a gallery, a sentimental object that once seemed indispensable. There is also something ghoulish about the act, recalling the buried-alive scenarios in Edgar Allan Poe's The Tell-Tale Heart and The Cask of Amontillado. This is Thurston's first exhibition since he won the prestigious Pollock-Krasner grant, and it shows a new sense of gravitas. At midcareer, he has abandoned the whimsy of his early portraits and the ebullience of his more recent gestural abstractions and seems to be embarking on a quest to answer, without flinching, life's biggest questions: When is it time to let go of our pasts, and what awaits us in the murky fog of our futures? This is a chilling, mature, unforgettable body of work.

SEE IT: Mel Katz's Anodized Aluminum is showing at Laura Russo Gallery, 805 NW 21st Ave., 226-2754. Through Feb. 25. Joe Thurston's Nothing Leading Anywhere Any More Except to Nothing shows at Elizabeth Leach, 417 NW 9th Ave., 224-0521. Through March 31.