There is a very strong lithostratigraphic and δ13C-chemostratigraphic resemblance between the well-exposed diamictite-cap dolostone-shale succession on eastern King Island, and the Marinoan glacials and lowermost Wilpena Group of the Adelaide Rift Complex. The strength of the resemblance suggests original lateral continuity of sedimentation between King Island and the Adelaide Rift Complex together with the contiguous central Australian Neoproterozoic epicratonic basins. On King Island, unlike mainland Australia, clastic sedimentation is interrupted by a thick succession of mafic, rift-related basalts and picrites at the level of the lower Brachina Formation equivalent. The evidence is consistent with King Island- and possibly the rest of western Tasmania- lying close to the Australian craton in Marinoan times, and rifting shortly after ca. 600 Ma.