In terminal Ediacaran strata of South China, the onset of calcareous biomineralization is preserved in the paleontological transition from Conotubus to Cloudina in repetitious limestone facies of the Dengying Formation. Both fossils have similar size, funnel-in-funnel construction, and epibenthic lifestyle, but Cloudina is biomineralized, whereas Conotubus is not. To provide environmental context for this evolutionary milestone, we conducted a high-resolution elemental and stable isotope study of the richly fossiliferous Gaojiashan Member. Coincident with the first appearance of Cloudina is a significant positive carbonate carbon isotope excursion (up to +6‰) and an increase in the abundance and (34) S composition of pyrite. In contrast, δ(34) S values of carbonate-associated sulfate remain steady throughout the succession, resulting in anomalously large (>70‰) sulfur isotope fractionations in the lower half of the member. The fractionation trend likely relates to changes in microbial communities, with sulfur disproportionation involved in the lower interval, whereas microbial sulfate reduction was the principal metabolic pathway in the upper. We speculate that the coupled paleontological and biogeochemical anomalies may have coincided with an increase in terrestrial weathering fluxes of sulfate, alkalinity, and nutrients to the depositional basin, which stimulated primary productivity, the spread of an oxygen minimum zone, and the development of euxinic conditions in subtidal and basinal environments. Enhanced production and burial of organic matter is thus directly connected to the carbon isotope anomaly, and likely promoted pyritization as the main taphonomic pathway for Conotubus and other soft-bodied Ediacara biotas. Our studies suggest that the Ediacaran confluence of ecological pressures from predation and environmental pressures from an increase in seawater alkalinity set the stage for an unprecedented geobiological response: the evolutionary novelty of animal biomineralization.

Demands for native volcanic sulfur as one of the ingredients of gunpowder reached a maximum during the early to middle 19th century, when abrupt changes in the political regime occurred in Japan. The historic commodity of sulfur prevailing during this time was analyzed for stable isotopic ratios (expressed as δ34S) to examine the provenance. The sampled sulfur involves the Siebold collection (acquisition by P. F. von Siebold in Nagasaki, northern Kyushu and kept in Naturalis, Leiden, The Netherlands) and Egawa library (Nirayama, central Japan) for which exact location of the origin is ambiguous or absent. The sulfur isotopic data were evaluated by comparison with the revised database for the spatial distribution of δ34S values of operative sulfur mines throughout the Japanese archipelagos. With a few exceptions, the commodity sulfur was transported through short-distance marketing systems within close proximity to Nagasaki and Nirayama.

This study uses stable isotope analysis to identify the possible origin and taxon of unusually large worked bone artifacts recovered from the site of Chavín de Huántar in the central highland of Peru (3200–2200 BP). The site was traditionally considered to be an ideal trading point halfway between the Pacific coast and the Amazon jungle. The archaeological specimens were discovered in a workshop area located in the La Banda sector across from the main temple, and they were analyzed for the stable isotopes of carbon, nitrogen, sulfur, and oxygen. Results indicate that the worked bone artifacts are marine in origin and are likely from a cetacean or large pinniped. Their exotic origin and elaborate work have implications about ancient production practices and exchange, and they provide benchmark data and a comparative approach for future analysis of exotic bone artifacts.

In archaeological dating, the greatest confidence is usually placed upon radiocarbon results of material that can be directly related to a defined archaeological event. Human bone should fulfill this requirement, but bone dates obtained from Pacific sites are often perceived as problematic due to the incorporation of 14C from a range of different reservoirs into the collagen via diet. In this paper, we present new human bone gelatin results for 2 burials from the SAC archaeological site on Watom Island, Papua New Guinea, and investigate the success of calibrating these determinations using dietary corrections obtained from δ34S, δ15N, and δ13C isotopes.