Microplastics as stratigraphic tracers of post-1950 deposition in a reworked tropical estuary, Brazil

This dataset supports the article "Microplastics as stratigraphic tracers of post-1950 deposition in a reworked tropical estuary, Brazil."
The data comprises the characterization of microplastics and fly ash particles sampled from a 240-cm sediment profile collected in the Cubatão River (Santos-Cubatão Estuarine System, SE Brazil).

Methods:
- Visual Identification: Particles were manually separated using a Zeiss stereomicroscope (Carl Zeiss GmbH) and an Axiocam 705 camera.
Morphometric analysis (major and minor axes) was performed via Zeiss ZEN 3.11 software.

- µ-FTIR Spectroscopy: Chemical identification was conducted using an Agilent Cary 630 spectrometer coupled to a Cary 610 FTIR microscope (ATR mode). Spectral range: 4000–550 cm-¹ at 4 cm-¹ resolution.

- SEM-EDS Analysis: Surface morphology and elemental composition were analyzed using a Scanning Electron Microscope (SEM) coupled with Energy-Dispersive X-ray Spectroscopy (EDS) (JEOL JSM-IT500HR).

- Data Processing: Raw transmittance spectra were converted to absorbance-like units (intensity) and normalized. A Savitzky-Golay filter was used for noise reduction, and linear interpolation was applied to remove atmospheric CO2 interference (2278–2389 cm-¹).