Microplastic's geochronology in coastal sediment: analysis based on optically stimulated luminescence (LOE), stable isotopes (13C), thermal analysis, and GNSS positioning

Abstract

In the coastal zone, the presence of plastic waste is notably the result of poor management of the disposal of this material, whether by direct disposal on the high seas from ships, transshipment in ports or adjacent industries, as well as being brought by sea currents and winds, urban or river drainage. Due to its characteristics of the high volume of production, low cost, and mainly, durability, there was an exponential global proliferation responsible for 80% of all the garbage accumulated in the oceans from the second half of the last century until today. However, even considering its recent appearance in geological terms, its impact on the terrestrial system has promoted significant changes of an anthropogenic character. In this way, this pollutant, which is also a technofossil, can be characterized as an essential stratigraphic component of the Anthropocene and an indicator of the loss of coastal ecosystem services associated with global environmental changes. In this context, the proposed research seeks an unprecedented assessment of the estimated rate of deposition of coastal sediments with microplastics overtime on sandy beaches in South America and Europe (Brazil, Portugal, and England) to identify when this pollution occurs, as well as point out its probable provenance or origin, combining optically stimulated luminescence (OSL) dating techniques, stable isotopes (´13C), thermal analysis (FTIR, TG, DSC) and geodetic survey supported by the Global Navigation Satellite System (GNSS). Contributing with relevant information on the stratigraphy and geochronology of this pollutant in the coastal sediment layers and the Anthropocene delimitation. (AU)