“Circular Earth” at the Spotlight Gallery in Montpelier presents the Vermont artist’s tight geometrical studies in natural materials. Shullenberger combines assemblage and collage with mandala-influenced symmetry to mesmerizing effect, emphasizing inherent natural tensions between order and chaos. Feathers, seedpods, sticks, reeds, acorns and birch bark are just some of the findings Shullenberger enlists in these carefully crafted compositions.