Geological and palynological characterization of a river beach in Portugal for forensic purposes

Abstract

AbstractCurrently, it is important to use a combination of independent analytical techniques in order to reliably characterize between different samples of geological trace evidence in criminal investigations. Areínho beach, in the town of Vila Nova de Gaia (northern Portugal), is located on the southern bank of the Douro River. Although isolated, it is a very busy area during the summer and other seasons due to its popular water sports. The geology of the area is complex, with numerous different outcrops. In addition, there is a considerable variety of vegetation in the region, and many materials are transported by the Douro River and deposited in the area.In order to characterize this beach for forensic purposes (both criminal and environmental), sediment samples were collected and analysed using a combination of geological techniques, namely colour, particle size distribution and mineralogy. These geological techniques were combined with a palynological assessment of the sediment samples. In addition, the surrounding vegetation was characterized and seasonal vegetation surveys were carried out.In this study, the results obtained revealed homogeneous data throughout the profile in all the properties analysed. This research demonstrated that the combination of different, independent techniques used to characterize sediments from this river beach has the potential to contribute substantially to future forensic investigations.