Mangroves, known as nurseries of marine life, deserve special attention due to their high ecological, economic, and social importance. However, mangroves are vulnerable to a range of anthropogenic activities, and it is estimated that half of the global mangrove cover has already been lost. This work is part of a larger project aimed at understanding the environmental changes occurring in the Amazon Basin. In this context, this thesis seeks to assess the geochronology of hydrocarbons extracted from mangrove sediments in the Amazon River mouth region. It is necessary to determine the concentrations of organic pollutants: aliphatic hydrocarbons (AHs), parental polycyclic aromatic hydrocarbons (PAHs) and their alkylated homologues using accelerated solvent extraction (ASE), column chromatography, and gas chromatography-mass spectrometry (GC-MS). Additionally, the interpretation of geochemical analyses performed and sediment dating by 210Pb provide essential support to achieve the proposed objective. The Amazonian cores analyzed are located on the coast of Amapá state, specifically in mangroves at the mouths of the Amazon, Araguari, and Sucuriju rivers. PAHs concentrations in the Araguari River mangrove varied from 22.29 to 66.50 ng.g to the power of -1 and AHs from 0.763 to 64.8 ug g to the power of -1. The Sucuriju River mangrove had the lowest hydrocarbon concentrations, with PAHs between 17.52 and 38.99 ng.g to the power of -1 and AHs from 0.200 to 1.63 ug.g to the power of -1. In the Bailique core, PAHs ranged from 45.35 to 110.6 ng.g to the power of -1 and AHs from 0.0660 to 4.91 ug.g to the power of -1, showing the highest PAH concentrations and greater anthropogenic contamination, resulting from tree burning, compared to other mangroves, although still indicating low contamination levels for PAHs.