Radiometric analysis of Quaternary deposits from the southeastern Brazilian coast

Natural gamma radiation measurements of the beach sand deposits were performed with the aim of understanding the provenance and transport processes of sediments along the coastal zone of three Brazilian States: São Paulo (SP), Rio de Janeiro (RJ) and Espírito Santo (ES). The method employs thorium, uranium and potassium as tracers of the mineralogical properties of beach sand minerals, which reflect the geological history of transport and sorting processes. A cross plot of eTh/eU and eTh/K shows a considerable positive correlation with the geological evolution of the Quaternary coastal deposits from 35 areas of the southeastern Brazilian coast. Additionally, the distribution of heavy minerals along this coastal zone was mapped.