This paper emphasises the generative qualities of the Anthropocene to explore how the geological turn with its interplay of life and nonlife might prompt new urban natureculture imaginaries and practices. In order to work towards an otherwise ontology that blurs the distinction between life and nonlife I think with the above- and below-ground composition of the urban grasslands of Melbourne, Australia. I consider what it might mean to live urban life as a becoming-geologic agent and geologic subject by drawing on the work of Isabelle Stengers, Elizabeth Povinelli and Hugo Reinert. The paper explores the multiple geontologies of Melbourne’s grasslands to emphasise how entities are assembled and made to matter in quite divergent ways that lend power to some modes of urban existence and not others. It considers the possibilities of a postcolonising urban cosmopolitics of geologic conviviality where humans live in concert not just with lively nonhumans, but with inert, inhuman, inorganic, non-biological entities.