Distribution of rare earth elements in sediments of the North China Plain: A probe of sedimentation process

Abstract

Rare earth elements (REE) are powerful tracers for our understanding of sedimentary provenance and depositional processes. This study investigated geochemical characteristics of REE in sediment samples collected from piedmont, central and littoral plains of the North China Plain. Results showed that total REE concentrations exhibited a decreasing trend as piedmont > central > littoral, and 82%, 70% and 67% samples had total REE concentrations higher than the value of Upper Continental Crust. The REE concentrations were controlled by sedimentary provenance and sediment physicochemical properties. Ternary diagrams of sandstone classification and Al 2 O 3 -CaO+Na 2 O-K 2 O reflected that sediments originated from greywackes and they experienced an incipient to intermediate chemical weathering. Average Chemical Index of Alteration values were 68, 51 and 55 for sediments from piedmont, central and littoral sediments, respectively. Sediment North American Shale Composite (NASC)-normalized patterns were characterized by light REE (LREE) enrichment over heavy REE (HREE) and coherent negative Eu anomalies (Eu/Eu* ranging between 0.57 and 1.00). Value of (La/Yb) NASC ranged from 0.86 to 1.15 (average 1.23), and from 1.03 to 1.49, and from 0.91 to 1.49 in three zones, indicating REE fractionation from piedmont to littoral occurred during sedimentation processes. A positive correlation between (La/Yb) NASC and total REE concentrations was observed in piedmont and central sediment samples, implying that LREE were preferentially enriched over HREE with an accumulation of REE. This positive correlation was not found in littoral sediment samples, where a general decreasing trend along depth for REE concentrations existed. Results of this study shows 3 implications for using REE as a tracer in provenance studies from a basin scale.

Assessment of the Anthropogenic Impact and Distribution of Potentially Toxic and Rare Earth Elements in Lake Sediments from North-Eastern Romania

“…No correlation between Ce/Ce* and Mn content was observed for the July samples (Pearson correlation coefficient of −0.0005), while in October the correlation coefficient was as high as −0.7577, reflecting an actually significant negative correlation of the Ce anomaly and the Mn content. The correlation between the Ce anomaly and Mn content is in agreement with other reports [ 9 , 12 , 20 , 61 , 62 ].…”

“…The extensive use of relatively new technologies is a major source of rare earth elements (REEs) in the environment, and the emission of REEs into natural waters is increasing [ 8 ]. The most important input of REEs in the environment is comprised by the fertilizers used in agriculture [ 9 , 10 ], intensive use in the industry, specific medical applications [ 9 , 11 ], and dry deposition of aerosol particles [ 8 ]. The REEs are characterized by very similar physicochemical behaviors [ 12 , 13 ], are very good tracers of chemical [ 14 , 15 , 16 ] and geochemical [ 9 , 16 , 17 ] processes, and may represent a new class of micropollutants that are not fully understood and could impact the environment.…”

Rare Earth Elements in Sediments from the Laptev Sea Shelf: Insight into Sources and Distribution Factors

“…Marine sediment REE properties are controlled by many factors, including grain size, mineralogical composition, marine biogenic components, diagenesis, hydrological regime, etc. [28,48,[64][65][66]. The grain size influence on REE content in sediments is explained by the fact that coarse sediment contains abundant REE-free quartz, while fine sediments are dominated by clay minerals, which are enriched in REEs [29,67,68].…”

“…Since REEs are characterized by the same layout of valence electrons in outer shell, their chemical properties are similar [19,24]. The highly conservative behavior of REEs during sediment formation makes them powerful geochemical tools in the study of marine sediments for determining depositional processes and sediment provenance, as well as for understanding paleoenvironmental changes [25][26][27][28][29][30]. This is because REE content in marine sediments is primarily controlled by origin, mineralogy, and, to a lesser extent, the intensity of chemical weathering [31].…”

Contamination, sources and risk assessments of metals in Stream Sediments of Pouma, Pan African Fold Belt, Southern Cameroon

“…Geological weathering, industrial disposal of metals and metal components, leaching of metals from garbage, solid waste heaps, mining, agriculture, pharmaceutical, domestic e uents, atmospheric sources, unplanned urbanization, haphazard industrialization, animal and human excreta are major sources of heavy metals and rare earth element (Chung 2018). The most important input of rare earth elements (REEs) in the aquatic environment include fertilizers used in agriculture, intensive use in the industry, speci c medical applications and dry deposition of aerosol particles (Sojka et al 2020;Liu et al 2021). Trace elements and rare earth elements pollution in the river environment can also have adverse effects on organisms and humans, enter the food chain, and accumulate in aquatic organisms, sometimes at harmful levels (Adeel et al 2019; Chan et al 2021).…”