Genesis and depositional environment of organic-rich sediments in the Neogene organic-rich sediments from the Aleksinac deposit (Serbia): Part B

Major, trace and rare earth elements dynamics in decomposing litters on successional sites in a cool temperate region of South Korea

The objective of this study was to analyse spatial variability of the trace elements (TEs) and rare earth elements (REEs) concentration in lake bottom sediments in Bory Tucholskie National Park (BTNP); Poland. The following research questions were posed: which factors have a fundamental impact on the concentration and spatial variability of elements in bottom sediments, which of the elements can be considered as indicators of natural processes and which are related to anthropogenic sources. The research material was sediments samples collected from 19 lakes. The concentrations of 24 TEs and 14 REEs were determined. The analyses were carried out using the inductively coupled plasma mass spectrometry (ICP-QQQ). Cluster analysis and principal component analysis were used to determine the spatial variability of the TEs and REEs concentrations, indicate the elements that are the indicators of natural processes and identify potential anthropogenic sources of pollution. The geochemical background value (GBV) calculations were made using 13 different statistical methods. However, the contamination of bottom sediments was evaluated by means of the index of geo-accumulation, the enrichment factor, the pollution load index, and the metal pollution index. The BTNP area is unique because of its isolation from the inflow of pollutants from anthropogenic sources and a very stable land use structure over the last 200 years. This study shows high variability of TE and REE concentrations in lake sediments. The values of geochemical indices suggest low pollution of lakes bottom sediments. It was found that TEs originated mainly from geogenic sources. However, the concentrations of Li, Ni, Sc, Se, Be, Se, Ag, Re, Tl, Cd, Sb and U may be related to the impact of point sources found mainly in the Ostrowite Lake. Almost all REEs concentrations were strongly correlated and their presence was linked to with geochemical processes. The elements allowing to identify natural processes and anthropogenic pollution sources were Cr, Co, Cu, Ag, Cd, Zn, Bi, Re, Ba, Al and Rb in TEs group and Nd, Gd, Yb, Lu, Eu, Dy and Ce in REEs group. The analysis shows high spatial variability of TE and REE concentrations in lake sediments. The values of geochemical indices point to low pollution of lakes sediments. The anthropogenic sources only for two lakes had an impact on concentrations of selected TEs and REEs. The analyses allowed to identify elements among TEs and REEs documenting geochemical processes and those indicating anthropogenic sources of pollution.

The formation and trace elements of garnet in the skarn zone from the Xinqiao Cu-S-Fe-Au deposit, Tongling ore district, Anhui Province, Eastern China

Geochemistry of hydrothermal alteration at the Qolqoleh gold deposit, northern Sanandaj–Sirjan metamorphic belt, northwestern Iran: Vectors to high-grade ore bodies

The concentrations of major, trace (TE), and rare earth (REE) elements and their seasonal and spatial distribution were studied on the fine fraction (<63 µm) of the sediments of the Lomé lagoons (West Lake, East Lake, and Lake Bè). The sediments were collected on a total of nine sampling sites (three per Lake) during two campaigns (dry season and rainy season). The quality of the sediments was assessed on the basis of the enrichment factor (EF) and the labile or non-residual fraction (NRF) in relation to the values recommended for the quality of the sediments (Sediment Quality Guidelines, SQG). The distribution of rare earth elements shows enrichments in light rare earths superior to those of heavy rare earth elements during any season. Positive Ce anomalies are less noticeable and less variable between seasons than Eu anomalies. La/Yb ratios are positively correlated with the percentage of Al and Fe oxides and with the percentage of fine fractions. The main bearing phases of rare earth elements are, therefore, Al and Fe oxides and the finest fractions of the sediments. The concentrations of trace elements vary little, according to the seasons, but show strong variations from one element to another. The degrees of enrichment obtained are moderate for Bi, Cr, Ga, Mo, Pb, Sn, and Zn (1.5 < EF < 5) to significant for As, Cd, and Sb (5 < EF < 20) for all sites of Lake Bè. For the sites of West Lake, the degrees of enrichment obtained are moderate for As, Cd, Cu, Mo, and Pb (1.5 < EF < 5) to a significance for As, Bi, Cd, Pb, Sb, Sn, and Zn (5 < EF < 20). Only the East Lake sites show high degrees of enrichment for elements such as Sb and Sn (20 < EF < 40). Trace elements (TE) such as As, Cd, Cu, and Ni have total concentrations within the range of variation of the SQG concentrations (particularly Probable Effect Level (PEL) and Effect Range Median (ERM)), whereas Cr, Pb, and Zn total concentrations are higher. The ranking of priority sites with respect to the sediment contamination is determined according to ERM and PEL quotients in relation to the probability of toxicity for benthic organisms. For almost all the sites, the priority is lowest to medium-low with regard to As, Cd, and Cu and medium-high (Cr and Ni) to highest (Pb and Zn), particularly for the East and West Lakes. Moreover, the NRF can represent significant percentages of the total TE concentrations: 5% to 15% for As, Bi, Ni, V, Mo, and Sc, 15% to 25% for Co, Cu, and Sr, 25% to 40% for Pb and Zn and, lastly, 47% to 55% for Cd.

Origin of oscillatory zoned garnets from the Xieertala Fe–Zn skarn deposit, northern China: In situ LA–ICP-MS evidence

In situ LA ICP-MS analysis of trace elements in scheelite from the Xuefeng Uplift Belt, South China and its metallogenic implications

통가열도 내 우리나라 해저열수광상 독점 탐사지역에 위치하는 5개 해저화산(TA12, TA19, TA22, TA25, TA26) 주변 표층 퇴적물의 열수변질 여부를 규명하고, 열수변질 특성을 확인하기 위하여 각 해저화산에서 채취된 29개의 표층 퇴적물에 대해 미량 원소와 희토류 원소 분석을 실시하였다. 분석 결과 TA12, TA19, TA22 해저화산에서는 열수에 의한 퇴적물의 변질작용이 없거나 매우 적은 것으로 나타났으며, TA25와 TA26 해저화산의 일부 지역은 현재에도 열수의 영향을 받고 있는 것으로 나타났다. 열수의 영향이 있는 해저화산 사이에도 부화된 미량 원소의 종류에 차이가 있는데, TA25 해저화산의 경우 주로 Ni, Cu, Sn, Zn, Pb, Cr, Cd, Sb, W, Ba, Ta, Rb, Sr, As가, TA26 해저화산에서는 주로 Cu, Sn, Zn, Pb, Cd, Sb, Ba, Rb, Sr이 부화되어 있다. 미량 원소의 부화가 확인된 지역은 희토류 원소의 부화도 관찰된다. 상부지각 희토류 원소 농도로 표준화된 희토류 원소의 분포형태는 가벼운 희토류 원소(LREE)가 매우 낮고 중간 희토류 원소(MREE)에서 무거운 희토류 원소(HREE)로 갈수록 증가하는 형태를 보이며, TA25와 TA26 해저화산의 일부 정점에서 Eu의 부화가 확인된다. 또한 TA26 해저화산의 일부 정점에서 Ce이 부화가 관찰되었는데, 이는 주변지역에서 채취된 열수 내 희토류 원소의 높은 Ce분포형태와 매우 유사하다. 또한 TA25와 TA26 해저화산은 부화된 원소의 특징이 다르게 나타나는데, TA25 해저화산에서는 Cu를 포함한 미량 원소가, TA26 해저화산에서는 Ce와 Eu를 포함한 희토류 원소가 우세하게 부화되어 있는 것으로 나타났다. 조사결과 나타난 각 해저화산 표층 퇴적물 내 부화된 미량 원소 및 희토류 원소의 종류와 농도는 차후 통가열도 지역의 열수광상 탐사시에 지역적인 열수변질의 지시자로써 유용하게 활용될 것으로 판단된다. We analyzed 29 surface sediment samples in five submarine volcanoes (TA12, TA19, TA22, TA25, and TA26) located in the southern part of the Tonga arc for trace elements and rare earth elements to investigate characteristics of the hydrothermal alteration of surface sediments. Based on analytical results of trace element and rare earth element (REE), surface sediments of TA12, TA19, and TA22 submarine volcanoes, which are located in the northern part of the study area, were very little or not influenced by hydrothermal fluids. In contrast, some stations of TA25 and TA26 submarine volcanoes were strongly affected by hydrothermal fluids. However, these two submarine volcanoes showed different features in element concentration in the sediments. Some stations of TA25 submarine volcano showed enrichment of Ni, Cu, Sn, Zn, Pb, Cr, Cd, Sb, W, Ba, Ta, Rb, Sr, and As, however, those of TA26 submarine volcano showed enrichment of Sn, Zn, Pb, Cd, Sb, Ba, Rb, and Sr. Stations which enriched trace elements were observed, enriched REEs were also observed. Average upper continental crust (UCC)-normalized REE patterns of the surface sediments generally showed low light REE (LREE) abundances and increased heavy REE (HREE) abundances. Eu enrichment was identified at several stations of TA25 and TA26 submarine volcanoes. In addition, enrichment of Ce was found at some stations of TA26 submarine volcano and these enrichment patterns were similar with hydrothermal fluid of near stations. Furthermore, TA25 and TA26 submarine volcanoes showed different enrichment characteristics of trace elements and REE. Trace elements were concentrated at TA25 submarine volcano. TA26 submarine volcano, on the other hand, observed highly enrichment of REE especially, Eu and Ce. As a result of the investigation, the characteristics and concentrations of REEs and trace elements in the surface sediments of each submarine volcano can be applied to identify hydrothermal alteration of sediments during exploration for hydrothermal deposits.

We investigated the concentrations of major, trace, and rare-earth elements in zooplankton in relation to species community composition from the eastern part of the Lena Delta to the continental slope of the Laptev Sea in September 2015. The elemental composition of zooplankton inhabiting different areas demonstrated similarities. Cross-shelf changes were found for only 4 (Li, Zn, As, and U) of the 56 elements analyzed. Zinc was the only element concentration of which successively reduced across coastal-open ocean gradient. Considering own and literary data, we can assume that the cross-shelf decrease of zinc accumulation in zooplankton is a universal pattern, manifested in different climatic and biogeochemical environmental conditions and with different species compositions of the zooplankton community. Cross-shelf changes were also established for Li, As, and U. However, the concentrations of these elements increased along the gradient. We assume that increased As concentration in zooplankton across the shelf-continental slope gradient of the Laptev Sea is associated with a change in the feeding behavior ofthe species of the zooplankton community. However, a sharp increase in the concentrations of Li and U in zooplankton was associated with the appearance of Calanus copepods in the community. The average total concentration of rare-earth elements and yttrium in zooplankton of the Laptev Sea was 752.8ngg-1 of dry weight. We found recordhigh levels of rare-earth elements for zooplankton of the inner shelf, near the eastern part of the Lena Delta. From the inner shelf to the continental slope of the Laptev Sea, La, Ce, and Nd were the dominant rare-earth elements. The elemental composition of zooplankton in the Arctic Seas is characterized by a much lower content of major and trace elements in comparison with the zooplankton and total plankton of the ocean.

The Huanggang deposit is the most important and largest skarn Fe–Sn polymetallic deposit in the Southern Great Xing’an Range of Northeast China. Cassiterite, magnetite, and other metal minerals are related to the garnets within skarn systems. The zoned garnets from various skarn stages are able to record numerous geological and mineralizing processes including variations in physicochemical conditions and hydrothermal fluid evolution. In this contribution, we present the mineralogy, systematic major, trace, and rare earth element (REE) concentrations of zoned garnets from the Huanggang Fe–Sn polymetallic skarn deposit. The in situ analytical results of garnets in the prograde skarn stage from andradite core (Grt I) to grossular rim (Grt II) reveal that core sections were formed from a fluid that was generally LREE-rich, with relatively high ∑REE, high LREE/HREE ratios, and weak negative Eu anomalies, whereas rim sections were crystallized from a fluid that was typically HREE-rich, with relatively low ∑REE, low LREE/HREE ratios, and obviously negative Eu anomalies. The garnets of the retrograde skarn stage from Fe3+-rich andradite core (Grt III) to andradite rim (Grt IV) demonstrate that the core sections have a flat trend with high ∑REE and obvious negative Eu anomalies, whereas rim sections were formed from a fluid with relatively low ∑REE, HREE-rich and obviously negative Eu anomalies. The garnets from the prograde skarn stage principally display relatively lower U and higher Y and F concentrations than those from the retrograde skarn stage. Based on optical and textural characteristics, REE patterns, Eu anomalies, and trace element variations in zoned garnets, it can be shown that, during skarn formation, Huanggang hydrothermal fluids shifted from near-neutral pH, oxidizing conditions, and high W/R ratios with relatively low LREE/HREE ratios characteristics to acidic, reducing conditions, and low W/R ratios with relatively high LREE/HREE ratios characteristics. We infer that variations in fluid compositions and physicochemical conditions may exert major control on formation and evolution of garnets and skarn hydrothermal fluids.

Lake pollution has attracted concerns worldwide; especially the excessive accumulation of trace elements (TEs) and rare earth elements (REEs) in bottom sediments can pose a serious threat to ecosystem health. However, there is still a knowledge gap on the level of sediment pollution in lakes isolated from the direct impact of pollution sources, their spatial variability, and also on the factors influencing this state. The aim of this study is to investigate the level and spatial variability of TEs and REEs concentrations, as well as to determine their source and the factors determining their distribution in the bottom sediments of Lake Ostrowite. Lake Ostrowite is the largest and deepest water body located in the Bory Tuholskie National Park (in northern Poland), which completely isolates the lake from the direct impact of pollution sources. The study covered analyses of 32 surface samples of bottom sediments. The concentrations of 24 TEs and 14 REEs were determined using inductively coupled plasma mass spectrometry (ICP‐QQQ‐MS). The assessment of the enrichment of bottom sediments in TEs and REEs employed geochemical background values (GBV) that provided the basis for the calculation of relative concentrations and geochemical indices. The determination of their sources and supply routes was based on the cluster analysis and principal component analysis. The obtained results point to the enrichment of the bottom sediments with TEs and REEs. Relative concentration values of TEs and REEs in reference to geochemical background values were in ranges from 0.01 to 7.31, at an average of 0.99, and from 0.03 to 4.29, averaging 1.76, respectively. The enrichment factor values show moderately severe enrichment of sediments at the study sites. This was primarily determined by the concentrations of Ag (from the TEs group) and Lu (from the REEs group). The metal pollution index values showed an approximate spatial distribution of points in terms of the presence of TEs and REEs. The lowest concentrations of TEs and REEs occurred on the eastern shore of the western basin of Lake Ostrowite. TEs and REEs concentrations in sediments are positively correlated with the content of organic matter and depth and negatively correlated with distance of the sampling point from the river outflow from Lake Ostrowite. On the eastern shore of the western basin, TEs and REEs concentrations are additionally shaped by wind, predominantly from the western direction. With water wave action, organic matter is transported to the central part of the western basin, where it is accumulated. Since the lake is isolated from point and nonpoint pollution sources, relevant from a biogeochemical point of view are dry and wet depositions from the atmosphere as well as aquatic vegetation, shoreline vegetation, forest litter, soil, and groundwater.

Major and rare earth elements (REEs) concentrations in sediment pore fluids are crucial for tracking biogeochemical processes during early diagenesis. However, the low concentrations and volumes typically sampled, particularly from long sedimentary sequences, limit our understanding of the REE behaviors in pore fluids. Here, major and trace elements have been analyzed on pore fluids from nine cores collected along the Penghu and Gaoping submarine canyons (SE Taiwan), in order to constrain diagenesis processes in sediments characterized by turbidite deposits and to determine their potential influence on the REE behavior in pore fluids. The ΣREE decrease from 600 to 200 pM in the upper 500 cm, with the maximum value attributed to the dissolution of Mn oxides in the redox transition zone. A decrease with depth of Ca and Mg concentrations are most probably associated with the formation of authigenic carbonate during the sulfate reduction process. This process absorbs REE from pore fluids without the REE fractionations. At deeper depth, an HREE enriched pattern is observed in core along the Penghu Canyon and might be linked to the degradation of organic matter in the methanogenesis zone. For cores located along the Gaoping Canyon, super-chondritic Y/Ho ratios comparable to seawater suggest a pronounced mixing of pore fluids with seawater and stronger scavenging of detrital sediments in the turbidity system. Overall, our results indicate that the REE concentrations in the pore fluids are relatively low and partitioning at deep depth in South Taiwan, REE distributions of pore fluids from turbidites sequences show a non-steady state variations in the high energy depositional setting. • Major and REE concentration profiles of pore fluids from the interface up to 40 m. • Better understanding of REE behaviors in pore water during early diagenesis processes. • Peaks in REE concentrations in pore water of the redox transition zone. • HREE enrichment in the pore fluids induced by methanogenic processes. • Impact of turbidites on REEs pattern of pore water (high Y/Ho and MREE enrichment).

...... The Kohistan terrane in the western Himalayan region is considered as a Cretaceous island-arc sequence sandwiched between the Asian and Indian continental crusts. It is a 300-kmlong plutonic body that extends parallel to the general trend of the Kohistan terrane. Rocks of this complex are petrographically and compositionally similar to plutonic xenoliths found in island arcs (Khan et al. 1989). We report geochemical data of rocks and minerals in the Chilas Complex and discuss the melt compositions and magmatism in middle to lower arc crust. The Chilas Complex is well exposed along the Indus and Swat Rivers. Most of the complex consists of generally homogeneous gabbronorite, pyroxene diorite and pyroxene quartz diorite, and these are called as the Main facies rocks. Some of the rocks were re-equilibrated under granulite facies conditions at 750-850 °C and 6-8 kbar (Swat valley, Jan and Howie 1980). Rocks with layered structure are also found in the Chilas Complex, which often occur in km-scale masses. Some of the masses are abundant in peridotites associated with layered gabbroic rocks (ultramafic-mafic association), which are deduced to be crystal accumulates. One of the bodies of the ultramaficmafic association, Thak body just to the east of Chilas town, shows excellent outcrops. This body is included in the Main facies rocks, and consists of cyclic units of layered cumulate rocks, which is classified into olivine-dominant cumulate (dunite-wehrlite), plagioclase-dominant cumulate (troctolite-gabbronorite) and pyroxene-dominant cumulate (websterite-clinopyroxenite). Hornblende and spinel are often included in the rocks. Mg values of the pyroxenes and An content of plagioclase are high in these cumulative rocks, but systematic change of major chemical composition of the minerals are not recognized through the Thak body. In addition, one gabbronorite mass along the Indus River (Basehri body) is characterized by well-developed rhythmic layering, and most of the layers were overturned. The Basehri body is intruded by the Main facies rocks, which is considered as crystal cumulate from the magma of the Main facies. Main facies rocks of the Chilas Complex have the characteristics of subduction-related calc-alkaline magmas with depletion of Nb relative to other incompatible elements (Khan et al. 1989). The concentrations of K2O, Y, Zr, Th and rare earth elements (REE) in the Main facies rocks are positively correlative with SiO 2 content. In the chondrite-normalized diagram, the light REE are enriched relative to heavy REE in the rocks, and the REE patterns are slightly concave upward. The chemical variation of the most of the Main facies rocks can be explained by a weak segregation of melt and early-formed crystals composed of plagioclase, clinopyroxene and orthopyroxene. The major element compositions of the rocks from the Thak body show the wide variation reflecting accumulation of earlystage crystals. Rocks are generally poor in REE and other incompatible elements, implying the separation of the melt and crystals are effective. Even the gabbroic rocks without olivine are still poor in REE and other incompatible elements relative to the Main facies rocks. REE concentrations of the layered rocks of the Basehri body are generally lower than those of the Main facies rocks. For characterization of magmas of these layered rocks, trace element compositions of clinopyroxene and plagioclase are determined by ICP-MS after mineral separation. Clinopyroxene fractions from wehrlite and websterite, and whole-rock sample of clinopyroxenite in the Thak body have REE, Ba, Nb, Sr and Zr concentrations similar to each other. The clinopyroxenite and the clinopyroxene from websterite have weak negative Eu anomaly and REE concentrations slightly higher than the clinopyroxene from wehrlite. The clinopyroxene from a plagioclase-rich part of the layered gabbronorite of the Basehri body shows the REE concentrations 3-5 times higher than clinopyroxenes from the Thak body, with clear negative Eu anomaly. Plagioclase fractions from a troctolite in the Thak body and from the plagioclase-rich rock of the Basehri body have REE concentrations with positive Eu anomalies, and they have similar Sr concentrations although the plagioclase from the troctolite are poor in most of the incompatible elements. The melts calculated from the clinopyroxenes of the pyroxene- and olivine-dominant cumulates in the Thak body are enriched in light REE relative to heavy REE, showing chemical characteristics closer to calc-alkaline or high-alumina basalt magmas in island arcs rather than depleted island-arc tholeiites. The calculated melts have REE, Sr and Zr concentrations similar to the Main facies rocks. The melts calculated from the plagioclase fractions have Sr, Ba and Rb concentrations similar to the Main facies rocks. These data suggest a possibility that the original magmas of the cumulates of the Thak body and the magma of the Main facies were derived from common or similar source materials, in spite of large petrographic variations. Trace element abundances in clinopyroxene and plagioclase from the Basehri body may have been affected by subsolidus equilibration, and also affected by a small amount of trapped melt.

The distribution of rare earth elements in groundwaters: assessing the role of source-rock composition, redox changes and colloidal particles

Application of LA-ICP-MS to sedimentary phosphatic particles from Tunisian phosphorite deposits: Insights from trace elements and REE into paleo-depositional environments