Silicified rocks at La Marciana farm, Deseado Massif, Argentinean Patagonia, represent an ancient hot-spring discharging into an active fluvial setting. Their fortuitous burial–erosion history and minimal post-depositional structural modification provide an unparalleled view of a complete, exhumed, late Jurassic geothermal landscape, and thus an opportunity to illuminate hot-spring geological context and palaeoenvironmental gradients. Geological mapping, stratigraphy and petrography revealed hydrothermal eruption events, the spring vent source, structural relationships, dimensions of the discharge apron, and hot-spring facies distributions. Remarkable similarities to Quaternary analogues from the Taupo Volcanic Zone, New Zealand, and Yellowstone National Park, USA, are apparent with respect to scale, spatial distribution of facies, and types of microbial and other palaeoenvironmentally significant fabrics.

The widely exposed Kuluketage diabase dyke swarm, Tarim Block, NW China, has been considered to have been emplaced in Permian times. New precise zircon U–Pb SHRIMP ages for two samples from the dyke swarm yield Neoproterozoic ages of 823.8±8.7 Ma and 776.8±8.9 Ma. Correlated with peaks of magmatism in South China and Australia at c. 825 Ma and c. 780 Ma, these two new ages provide significant information for palaeocontinental reconstructions. The prolonged duration of the magmatic events, combined with regional stratigraphic relationships, imply that the Tarim Block may have been affected by a mantle plume during the breakup of Rodinia.

We describe the first occurrence of the problematic fossil Gaojiashania outside China, in the Ediacaran Yudoma Group of the Siberian Platform. In both areas, Gaojiashania characterizes the lower upper Ediacaran strata and precedes the appearance of Cloudina and other skeletal fossils, which highlights its significance for the Ediacaran subdivision and correlation. Features of this fossil such as indeterminate length, the absence of a distinct growth pattern, and self-avoiding behaviour indicate its trace fossil origin but do not necessarily imply metazoan affinities for its producers. Several organisms including stem-group social amoebozoans and unicellular protists may have been Proterozoic trace fossil producers.