Lanthanides and Actinides in Humic Acids of Soils and Paleosols of Forest-Steppe Conditions in the Southern Urals

Abstract

This article analyzes the lanthanum, cerium, samarium, europium, terbium, ytterbium, lutetium, uranium, and thorium content in humic acids within soil and paleosol surface horizons from the southern steppe in the Southern Urals. Research demonstrates similar accumulation levels of these elements in paleosols isolated from both the active medium between 3.6 and 3.3 thousand years ago and in recent background soils. Despite the lack of significant differences, research has shown a growing content among the rarest metals in the series "the buried paleosols-man-modified paleosols of settlement-recent background soils". Research has detected the lowest content of La, Ce, Sm, Eu, Yb, Lu, and Th in preparations of humic acids of recent background soils. This reveals a close content to most elements in humic acids of paleosols buried under barrows and ancient settlement paleosols. Additionally, it indicates the virtual absence of anthropogenic impact on binding lanthanides and actinides by humic acids in ancient times. The contribution of humic acids into the common pool for each element was evaluated using a special approach. Research showed that there was less than half the share of elements associated by humic acids of paleosols than in the recent background chernozems in the total pool of lanthanides and actinides. This article considers the prospects of using humic acids of recent and ancient soils in identifying behavioral patterns of metal complexes through time.

Impact of anthropogenic factor on changes in physical and chemical properties of chernozems in the lake Sevan basin of the republic of Armenia

“…The humus state of soils is greatly influenced by anthropogenic factors, the level of cultivation, etc. [8][9][10][11].…”

Polish Polar Research

“…It is the accumulative nature of HAs, their ratio versus FAs due the bioclimatic conditions, the ability of the system to organize and regulate itself as well as preserved key properties of humus in diagenesis that allow for using humic substances as markers of soil formation stages and phases (Kallas and Dergacheva 2011;Kukuļs et al 2019). The humus profile captures everything, even short-term environmental changes, and reflects soil development stages and phases which are diagnosable even (Dergacheva et al 2018;Rodrigues et al 2019). A number of articles have been published in Russia so far stating major regularities for the change of structural and functional parameters of humic substances as affected by bioclimatic and zonal factors (Orlov 1995;Kholodov et al 2011;Dergacheva et al 2012).…”

Analysis of stratigraphical sequences at Cocina Cave (Spain) using rare earth elements geochemistry

“…Rare earth elements (REE) have traditionally been employed with other trace elements to distinguish sediments associated with human occupation belonging to different contexts (Entwistle et al 2000;Cook et al 2006;Elmaleh et al 2012;Nielsen & Kristiansen 2014;Butler & Dawson 2018;Dergacheva et al 2018;Sulas et al 2019). However, REE signatures have been recently employed by Gallello and colleagues (Gallello et al 2013;2019a, b) in archaeological strata to determine differences between natural and human-induced In the Serpis Valley region (Spain), a marl-based geological area, REE soil analyses have been demonstrated to provide significant details about anthropogenic layers, suggesting that the archaeological interpretation of some dark brown deposits is evidence of a Neolithic region-wide agricultural system (Gallello et al 2019b).…”