Geochemical and Geochronological Constraints on the Provenance and Heavy Metal Contamination of Beach Sediments Along the Gulf of Mexico, Mexico

This study investigates the textural characteristics, mineral composition, and U–Pb ages of detrital zircon grains from the Playa Norte (PN) and Playa Tamiahua (PT) beach sediments along the Gulf of Mexico (GoM). The objective is to trace the sediment origin and to identify the possible environmental impacts in the coastal ecosystem. This work represents the first integrated provenance and geochemical analysis performed in these beaches, contributing to a broader regional sedimentological and geochronological database for the GoM. The results reveal distinct compositional and provenance signatures: PN sediments are rich in quartz (57.7% avg.), feldspars (15.7% avg.), and carbonate minerals (8.6% avg.), with zircon populations dominated by Proterozoic ages (~820–2200 Ma) and minor anthropogenic enrichment. In contrast, PT exhibits higher contents of quartz (78.6% avg.), andesine (9.6% avg.), and anorthite (8.5% avg.), with zircons mainly of Oligocene age (~32 Ma) and minimal contamination. Comparison with potential source regions indicates that PN sediments were derived primarily from the Sierra Madre Oriental, while PT sediments were originated from the Mesa Central and Eastern Mexican Alkaline Provinces. Overall, the findings demonstrate that, beyond littoral mixing and sediment recycling, the composition of GoM coastal sediments reflects the region’s complex tectono-sedimentary evolution and variable natural versus anthropogenic influences. PN is enriched in arsenic content, which is associated with agricultural activities and oil industries, while PT exhibits low values with no evidence of contamination. Meanwhile, Cr in PN suggests an anthropogenic input, which is linked to oil exploration activities in the GoM.