Oakland sculptor Matt Dostal discerns "shapes, patterns, and meaning" in "post-industrial waste, often culled from local landfills, shorelines, [and] sidewalks," and he works these suggestive bits of scavenged wood to create wall-hung shallow-relief assemblages suggestive of walls or fences that have broken or eroded into fortuitous shapes. The use of found materials in abstraction derives from Cubism and Dada, and Dostal's forms preserve their workaday thingness while hinting, as assembled, at illegible texts - "sculptural flat zines." The vertical striations between planks in some pieces suggest growth and expansion, pleated garments, birds, pan pipes, and even dripping paint; the shapes in others suggest utensils or tools (like the pruning shears in "Tree"). The ambiguity continues in the somewhat dissonant (i.e., elusively allusive) titles: "Elephant," "Grandfather Clock," "Squid," "Alluvion Wave," "Whitey's on the Moon," "King Tough." Consonant Detritus runs through July 30 at FM (483 25th St., Oakland). FMOakland.com.