Abstract The use of soil evidence to identify an unknown location is a powerful tool to determine the provenance of an item in an investigation. We are particularly interested in the use of these indicators in nuclear forensic cases, whereby identification of locations associated with, for example, a smuggled nuclear material, may be used to indicate the provenance of a find. The use of soil evidence to identify an unknown location relies on understanding and predicting how soils vary in composition depending on their geological/geographical setting. In this study, compositional links between the mineralogy of 40 soils and the underlying bedrock geology, as documented in local-scale geological maps, were established. The soil samples were collected from locations with broadly similar climate and land use across a range of geological settings in a ‘test bed’ 3500 km 2 area of SW England. In this region, the soils formed through chemical weathering of the bedrock, representing a worst case scenario for this type of forensic geolocation owing to the high degree of alteration of the parent rock during soil formation. The mineralogy was quantified using automated scanning electron microscopy–energy dispersive X-ray spectrometry analysis based on QEMSCAN technology. Soil mineralogy and texture as measured using this technique are consistent with the underlying geology as indicated by regional-scale geological mapping. Furthermore, differences between individual units of the same bedrock lithology, such as different granites, were identified by examining trace mineralogical signatures. From an investigative viewpoint, this demonstrated that rapid automated mineral profiling of soil samples could be used, in conjunction with readily available geological mapping or similar datasets, to provide indication of the areas from which a soil sample of unknown origin could, or could not, have been sourced.

Abstract Most of the Precambrian (>538 Ma) fossil record, which includes the time before the onset of macroscopic multicellular life, consists of minute organically preserved remains of soft-bodied micro-organisms, i.e. non-pollen palynomorphs (NPP). These microfossils include single-celled prokaryotic or eukaryotic organisms, filamentous sheets and bacterial cellular aggregates, and occur in marine and lacustrine sediments through most of the Earth's history. Ancient NPP have informed our understanding of one of the biggest evolutionary steps in the history of life: the origin of the eukaryotic cell and the subsequent diversification of eukaryotic life before the evolution of macroscopic forms. The oldest widely accepted eukaryotic microfossils are large cells with opening structures and ornamentation from upper Paleoproterozoic units in China and India. NPP diversify through Meso- and Neoproterozoic Eras, notably recording the oldest multicellular life around 1 billion years ago. In the latest Neoproterozoic, during the advent of animal life, the NPP record allows us to study the cryptic evolution of animals while they were exclusively small and poorly or non-mineralized before the appearance of organisms with hard parts. We review the current understanding of the early eukaryotic evolution and major advances in Precambrian palaeontology through the lens of the NPP record in deep time.