This study examines textural characteristics, carbonate, organic carbon and chemical composition of sediment samples recovered in the nearshore region (~3–19 m water depth) at the Grijalva River mouth, southern Gulf of Mexico. The aim of this study is to assess the heavy metal contamination and provenance variations in sediments between the dry and northers (rainy) seasons. The proportion of sand, carbonate, and organic carbon contents were abundant at sites located near to the Grijalva River mouth, principally in northers season. Silt content is dominant in the dry season, especially in the sites located away from the Grijalva River mouth. The Chemical Index (CIX) values obtained for the dry (~76–84) and northers (~75–87) seasons indicated a moderate to high intensity of weathering and a humid climate in the source area. The low K₂O/Al₂O₃ ratio values (<0.5) in the dry and northers seasons indicated a higher proportion of aluminosilicates than detrital minerals, due to moderate-to-high intensity of weathering. The correlation among elemental concentrations revealed the association of Cr, Nb, Zr, Hf, Y, and rare earth elements (REE) with detrital minerals rather than aluminosilicates. The major element concentrations, Th/Sc, La/Sc, Co/Th, and Cr/Ni elemental ratios indicated the derivation of sediments from intermediate and mafic igneous rocks. A similarity in the North American Shale Composite (NASC) normalized rare earth element (REE) patterns and Eu anomaly between the dry and northers seasons suggested that the variations in sediment input played a less significant role and the provenance of sediments remained constant. The enrichment factor (EF) showed moderate to severe enrichment for Cr, Ni, and Sb (EF = ~2.63–7.57), highest in the northers season, especially at the Grijalva River mouth, although the index of geo-accumulation (I_geo) for these elements suggested as moderately polluted (I_geo = 0.34–2.0). The slightly elevated EF values for Cr, Ni, and Sb during northers season were probably due to an increase in sediment discharge into the sea during the northers season. We inferred that the enrichment of Cr, Ni, and Sb in sediments was due to both lithogenic and anthropogenic origins. The sediments were influenced by the intermediate and basic igneous rocks of the Chiapas Massif Complex, and the waste generated by the urban areas located within the Grijalva River drainage basin.

这项研究检查了墨西哥湾南部格里雅尔瓦河口附近海岸地区（水深约3–19 m）回收的沉积物样品的质地特征，碳酸盐，有机碳和化学成分。这项研究的目的是评估旱季和北方（雨季）之间重金属的污染和沉积物中物源的变化。主要在北风季节，靠近Grijalva河口的地点的沙子，碳酸盐和有机碳含量丰富。在干旱季节，淤泥含量占主导地位，尤其是在远离格赖瓦尔河河口的地方。干燥（〜76–84）和北方地区获得的化学指数（CIX）值（〜75–87）个季节表示源区中度到中度的高强度风化和潮湿的气候。干旱地区和北方地区的K ₂ O / Al ₂ O ₃比值低（<0.5）季节表明铝硅酸盐的比例高于碎屑矿物，这是由于中等至高强度的风化作用所致。元素浓度之间的相关性揭示了Cr，Nb，Zr，Hf，Y和稀土元素（REE）与碎屑矿物而不是铝硅酸盐的关系。主要元素浓度（Th / Sc，La / Sc，Co / Th和Cr / Ni元素比）表明来自中，镁铁质火成岩的沉积物。北美页岩组合（NASC）归一化稀土元素（REE）模式与干北向之间的Eu异常相似季节表明，泥沙输入的变化所起的作用较小，而泥沙出处则保持不变。富集因子（EF）显示出Cr，Ni和Sb的中到重度富集（EF =〜2.63–7.57），在北部季节最高，特别是在Grijalva河口，尽管地理积累指数（I _geo），因为这些元素建议为中度污染（I _geo = 0.34–2.0）。期间稍微升高EF值铬，镍，和Sb northers赛季很可能是由于期间增加泥沙排放入海northers季节。我们推断，沉积物中Cr，Ni和Sb的富集是由于成岩作用和人为原因引起的。沉积物受恰帕斯州地块复合体的中，基性火成岩以及格里亚瓦尔瓦河流域内市区产生的废物的影响。