Fig 1.
Geological map of the DAM with the location of the collected samples.
In the inset, the geotectonic sketch of Romania. The map was created based on the information from various sources [44,47,59,60]. We used the color code for lithology from [61].
Table 1.
Main and accessory minerals identified with the powder XRD and SEM-EDX analysis.
Table 2.
ICP-MS results of major elements content* in the river sediments.
Table 3.
ICP-MS results of trace elements in mg·kg-1.
Fig 2.
Distribution maps of trace elements along the Ditrău and Jolotca river.
a) Lithium; b) Nickel; c) Niobium; d) Tantalum; e) Uranium; f) Thorium.
Fig 3.
Distribution maps of REE along Ditrău and Jolotca rivers.
a) Lanthanum; b) Cerium; c) Praseodymium; d) sum of REE; e) sum of Light REE; f) sum of Heavy REE.
Table 4.
Rare earth element contents (mg·kg-1) in.Ditrău and Jolotca rivers.
Table 5.
Enrichment Factor values* for the REE contents in.Ditrău and Jolotca rivers.
Fig 4.
Trace elements of river bed sediments normalized to the average values of the UCC.
a) Ditrău River, b) Jolotca River.
Fig 5.
Pearson correlation between trace elements and REE for Jolotca and Ditrău rivers.
Fig 6.
Heavy minerals enrichment of samples based on the variability in a) ΣREE vs. Ti pair and b) ΣREE vs. Zr pair.
Fig 7.
Source and compositional discrimination diagram for our study area (modified after [83]).
Table 6.
Different REE concentrations in river sediments from different areas and our study.
Fig 8.
REE normalization to the UCC and to Chondrites for the samples from Ditrău (a, c) and Jolotca (b, d).
Fig 9.
Inter-correlation of the REE fractionations pointing out the freshness and the nature of the lithogenic supplies.
xy plan: Ndn/Ybn = f(Ce/Ce*); xz plan: Ndn/Ybn = f(Eu/Eu*); yz plan: Ce/Ce* = f(Eu/Eu*).
Fig 10.
Correlation plots of ∑REE, ∑HREE, and ∑LREE with Ca and P for the analyzed samples.
a, b, and c) correlation plots of ∑REE, ∑HREE, and ∑LREE with Ca for Ditrău samples; d, e, and f) correlation plots of ∑REE, ∑HREE, and ∑LREE with P for Ditrău samples; g, h, and i) correlation plots of ∑REE, ∑HREE, and ∑LREE with Ca for Jolotca samples; j, k, and l) correlation plots of ∑REE, ∑HREE, and ∑LREE with P for Jolotca samples.