Geochemistry of re and trace elements in ferromanganese nodules and their genesis

Trace and RE element geochemistry and genesis have been studied with respect to ferromanganese nodules from the sediments of the Pacific, Atlantic and Indian oceans.     

Potential Effects of Episodic Deposition on Nutrients and Heavy Metals in Decomposing Litters of Suaeda glauca in Salt Marsh of the Yellow River Estuary,China

Episodic deposition has been recognized as a major factor affecting the decomposition rate of detrital material in salt marshes. In this paper, three one-off burial treatments, no burial treatment(0 cm, NBT), current burial treatment(10 cm, CBT) and strong burial treatment(20 cm, SBT), were designed in intertidal zone of the Yellow River Estuary to determine the potential influences of episodic deposition on nutrient(C, N) and heavy metal(Pb, Cr, Cu, Zn, Ni, Mn, Cd, V and Co) variations in decomposing litters of Suaeda glauca. Results showed that although various burial treatments showed no statistical difference in decomposition rate of S. glauca, the values generally followed the sequence of CBT(0.002 403/d) SBT(0.002 195/d) NBT(0.002 060/d). The nutrients and heavy metals in decomposing litters of the three burial treatments exhibited different variations except for N, Cu, Cr, Ni and Co. Except for Mn, no significant differences in C, N, Pb, Cr, Cu, Zn, Ni, V and Co concentrations occurred among the three treatments(P 0.05). With increasing burial depth, Cr and Cd levels generally increased while Cu, Ni and Mn concentrations decreased. Although episodic deposition was generally favorable for C and N release from S. glauca, its influence on release was insignificant. In the three burial treatments, Pb, Cr, Zn, Ni, Mn, V and Co stocks in S. glauca generally evidenced the export of metals from litter to environment, and, with increasing burial depth, the export amounts increased greatly. The S. glauca were particular efficient in binding Cd and releasing Pb, Cr, Zn, Ni, Mn, V and Co, and, with increasing burial depth, stocks of Cu in decomposing litters generally shifted from release to accumulation. The experiment indicated that the potential eco-toxic risk of Pb, Cr, Zn, Ni, Mn, V and Co exposure would be serious as the strong burial episodes occurred in S. glauca marsh.     

化探样品中部分元素测定溶矿方法的改进

文章研究了用 1∶1王水分解化探样品中Cu、Pb、Zn、Co、Ni、Fe、Mn等元素新的样品溶解测定方法 ,即王水分解测定法 ,该法的检出限、准确度、精密度均达到 1∶5万化探样品分析要求。此法已用于化探及区域地质普查样品分析 ,并取得了较好效果     

TraceeElements in Leccinum scabrum mushrooms and topsoils from Kłodzka Dale in Sudety Mountains, Poland

In the current study, we determined concentrations and transfer rates of Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, P, Rb, Sr and Zn to Brown Birch Scaber Stalks (Leccinum scabrum) mushrooms emerged in the area of Sudety Mountains (Sudetes) in Poland. Fruiting bodies and topsoil samples beneath L. scabrum were collected form the K odzka Dale. The trace elements were determined using validated method and inductively coupled plasma - atomic emission spectroscopy (ICP-AES) for final measurement. Mushrooms contained Ag, Cr, Hg, Co, Ni and Sr at < 1.0 μg/g dry weight; Ba and Pb at ~1.0 μg/g dw; Cd at < 5 μg/g dw; Cu and Mn at > 10 μg/g dw; Al and Ca at ~100 μg/g dw; Fe, Na, Rb and Zn at 100 to 500 μg/g dw, Mg at ~1,000 μg/g dw; P at ~5,000 μg/g dw and K at ~30,000 μg/g dw. Ca, Mn and Ni were nearly equally distributed between stipes and caps; stipes compared to caps were enriched in Ba, Na and Sr, while caps were enriched in Ag, Al, Cd, Co, Cr, Cu, Fe, K, P, Pb, Rb and Zn. The values of bioconcentration factor (BCF) varied highly depending on chemical element and were >1 for Ag, Cd, Cu, K, Mg, Na, P, Rb and Zn, while <1 for Al, Ba, Ca, Co, Cr, Fe, Mn, Ni, Pb and Sr. Topsoil showed elevated content of lead and mean concentration was 99 ± 32 μg/g dw, while cadmium was at 0.41 ± 0.15 and those two highly toxic to human elements occurred in edible caps of L. scabrum at 4.5 ± 2.2 and 2.9 ± 2.0 μg/g dw, respectively.     

Factors controlling the distribution of transitional metal elements in marine hydrogenic ferromanganese crusts

A series of selective dissolution experiments were conducted on the hydrogenic ferromanganese crusts collected near Line Island to study the geochemistry of Mn, Fe, Cu, Co, Ni and Ti. Despite of the fact that the very close intergrowth between amorphous ferric oxyhydroxides and δ-MnO2 exists in the hydrogenic ferromanganese crusts, there is no isomorphous substitution between iron and manganese. This is because the two elements in oxides have different crystal chemistry and geochemistry, such assertion bein...     

A study of iron and manganese in the western Mid-Pacific

Our study on the horizontal and vertical distribution, change pattern, and migration form origin of iron and manganese and the factors affecting them in surface sediment in the western Mid-Pacific and in columnar sediment of station L 2032 is introduced. The author inferred the lysocline and compensation depth of the ocean by using the content changes of Fe and Mn; differentiated rapidly sedimentation types by using the difference of Fe and Mn contents, estimated tentatively their contents in different sediments by using the dyeability of Fe and Mn. The author notes that the economically valuable Fe−Mn nodules can be formed during Fe−Mn deposition in the ocean and that in studies on Fe and Mn deposition, the affecting factors should be analyzed comprehensively.     

Statistical analysis of the material source and the modern sedimentary environment of the ferromanganese nodules enriched area of the North Pacific region

The source of elements and the modern sedimentary environment of the ferromanganese nodules enriched area of the North Pacific region were analysed statistically and discussed in detail. Cluster analysis shows the area's surface sediments are mainly brown clay and biogenic calcareous, calcsiliceous and siliceous ooze. Factor (principal component) analysis shows that the area's trace elements (Fe, Mn, Cu, Co, Ni, Zn, Cr, etc.) mainly come through adsorption of clay minerals and secondarily from authigenic sediments related to biochemical processes. Bao Gende, 1990. Characteristics of element geochemistry in sediments in the ferromanganese nodules enriched area of the North Pacific region.Acta Sedimentologica Sinica. (in press, in Chinese)     

The influence of seafloor hydrothermal activity on major and trace elements of the sediments from the South Mid-Atlantic Ridge

Sediment samples obtained from the South Mid-Atlantic Ridge were analyzed for the major and trace elements by inductively coupled plasma atomic emission spectroscopy and inductively coupled plasma mass spectrometry. Results revealed that the contents of elements (e.g., Fe, Mn, Cu, Zn, V, Co) were high in samples 22V-TVG10 and 26V-TVG05 from the sites near the hydrothermal areas, and low in sample 22V-TVG14, which was collected far from the hydrothermal areas. The contents of Ca, Sr and Ba in the samples showed opposite trends. A positive correlation between the concentrations of metallic elements (Cu, Zn, Co, Ni, Pb, V) and Fe in the samples were observed. These results are consistent with chemical evolution of the dispersing hydrothermal plume.     

Redox conditions in sediments and during sedimentation in the Ontong Java Plateau, west equatorial Pacific

Redox-sensitive elements in sediments, such as manganese (Mn), vanadium (V), molybdenum (Mo), and uranium (U), are promising indicators of past redox conditions during sedimentation and early diagenesis. However, in the Ontong Java Plateau, west equatorial Pacific, there are sparse datasets of redox-sensitive elements in sediment cores. Here, we present a 250 ka record of redox sensitive elements from a 460 cm gravity core at site WP7 (3°56′S, 156°E, water depth 1 800 m), which was recovered from the southwest Ontong Java Plateau during the 1993 cruise of R/V Science I of the Institute of Oceanology, Chinese Academy of Sciences (IOCAS). Relative to the Post-Archean Australian Shale (PAAS), authigenic Mn, cobalt (Co), nickel (Ni), Mo, V, U, and cadmium (Cd) were found at constantly low levels except when peaks occurred at several depth intervals. Manganese, Co, Ni, and Mo concentrations were elevated at 25-35 cm due to Mn redox cycling. The core was divided into three distinct sections, the top 0-25 cm being oxic, a suboxic section at 25-35 cm and from 35-460 cm which was anoxic. Differential authigenic enrichments of Co, Ni, Mo, V, U, and Cd at the same depth intervals were observed indicating that the enrichments happened during sedimentation or diagenesis and suffered no post settlement redox changes. Therefore, no significant changes in redox conditions during sedimentation must have happened. The water at depth on the Ontong Java Plateau during past 250 ka must have been well oxygenated, possibly resulted from the more or less continuous presence of oxygen-rich deep water like the modern Antarctic Intermediate Water (AAIW) and Antarctic Circumpolar Water (ACW); while it’s slightly less oxygenated in glacial intervals, possibly due to ventilation weakening and/or the surface productivity increase.     

GEOCHEMICAL STUDY OF THE CORE S01 IN THE SOUTH CHINA SEA

Si, Ti, Al, Fe, Mn, Ca, Mg, K, Na, P and Sr, Ba, Rb, Ga, V, Zr, Cr, Ni, Co, Cu, Zn, Pb,Nb, Y, Th, La in the core S01 were analyzed and the pattems of their enrichment are discussed.Enrichment of Na, Fe, Mn, Ba, Cu elements in the core indicates volcanic material are an importantsoarce of the sediments in the area. The enrichment frequently varying with the deposition processshows bottom volcanism is frequent in the area and that the studied area is a margin basin with distinctoceanic characteristics. The abnormal enrichment of Mn at the layers(0-15 cm and 665-670 cm) of the core could beclosely related to and so, indicate, the wide deposition hiatus that have occurred in the West PacificOcean and adjacent margin seas since Late Pleistocene.     

Fe-Si-Mn-Oxyhydroxide Encrustations on Basalts at East Pacific Rise near 13°N:An SEM-EDS Study

Fe-Si-Mn-oxyhydroxide encrustations at the East Pacific Rise(EPR) near 13°N were analyzed using the scanning electron microscope(SEM) with an energy dispersive spectrometer(EDS). These encrustations are mainly composed of amorphous FeSi-Mn-oxyhydroxides forming laminated, spherical, porous aggregates with some biodetritus, anhydrite, nontronite, and feldspar particles. Anhydrite particles and nontronite crystals in the Fe-Si-Mn-oxyhydroxide encrustations imply that the Fe-Si-Mn- oxyhydroxide may have formed under relatively low- to high-temperature hydrothermal conditions. The Fe-Si-Mn-oxyhydroxide encrustations on pillow basalts are 1–2 mm thick. The growth rate of ferromanganese crusts in the survey area suggests that these encrustations are an unlikely result of hydrogenic deposition alone having a hydrothermal and(Fe/Mn ratio up to 7.7 and Fe/(Fe+Mn+Al) ratio exceeding 0.78) hydrogenic origin(0.22 Fe/Mn ratio close to the mean value of 0.7 for open-ocean seamount crusts). The varying Fe/Mn ratios indicate that the Fe-Si-Mn-oxyhydroxide encrustations have formed through several stages of seafloor hydrothermalism. It is suggested that, at the initial formation stage, dense Fe-Si-oxyhydroxides with low Mn content deposit from a relatively reducing hydrothermal fluid, and then the loose Fe-Si-Mn-oxyhydroxides deposit on the Fe-Si-oxyhydroxides. As the oxidation degree of hydrothermal fluid increases and Si-oxide is inhibited, Mn-oxide will precipitate with Fe-oxyhydroxides.     

Heat center of the western Pacific warm pool

A heat center (HC) of the western Pacific warm pool (WPWP) is defined, its variability is examined, and a possible mechanism is discussed. Analysis and calculation of a temperature dataset from 1945-2006 show that the mean position of the HC during this period was near 0.4°S/169.0°E, at 38.0 m depth. From a time series of the HC, remarkable seasonal variability was found, mainly in the meridional and vertical directions. Interannual variabilities were dominant in the zonal and vertical directions. In addition, semiannual variation in the HC depth was discovered. The longitude of the HC varies with ENSO events, and its latitude is weakly related to ENSO on time scales shorter than a decade. The variation of the HC longitude leads the Nio-3 index by about 3-4 months, and its depth lags the index for approximately 3 months. It is concluded that the HC depth results from a combination of its longitudinal and latitudinal variations. Low-pass-filtered time series reveal that the HC has moved eastward since the mid 1980s.     

A study on element-stratigraphy of Okinawa Trough

Regular distribution patterns of elements Ca, Sr, K, Na, Mg, Fe, Mn, Ti, Cu, Co, Ni, Zn, Pb, Cr, Rb, Ba, Cd, and U in Late Quaternary strata have been studied in detail. The regional variation patterns of elements in these strata are similar to those in recent surface sediments, showing that the sedimentary environment has been relatively stable since Late Quaternary. Element distribution changes with the variations of lithological characters. Contents of Ca and Sr increase in coarse sediments, while those of other elements decrease. Na content increases in the pumice layer. Mn, content tends to increase sharply towards the surface layer. Ca content decreases sharply in strata where water depth is more than 2,000 m. The strata can be divided based on the distribution curves of element assemblages. The variations in contents of most elements in Holocene Series are smaller than those in Late Pleistocene Series, which might be related to the factors of glacial and interglacial changes, sea level fluctuations and material source differences. Contribution No. 1488 from Institute of Oceanology, Academia Sinica     

Controlling mechanisms for the trace metals, (Cu,Zn, Cd,Fe, Co and Ni) in anoxic sea water in Saanich Inlet,British Columbia,Canada

A study was conducted on Cu, Zn, Cd, Fe, Co and Ni levels in Saanich Inlet anoxic seawater. Data on the concentration of these trace metals and H₂S, and other oceanographic parameters were obtained in four cruises. Equilibrium models are presented together with in situ data. The results strongly support the assumption that the solubilities of Cu, Zn, Cd, Fe, Co and Ni are controlled by bisulfide and/or polysulfide complexes. The species of Cu, Zn, Cd and Ni are shown to be Cu(S₄) ₂ ³⁻ and Cu(Sn₄S₅)³⁻, Zn(HS) ₂ ⁰ and ZnHS ₂ ⁻ , Cd(HS) ₂ ⁰ and Ni(HS) ₂ ⁰ , respectively. The solid species controlling Fe²⁺ and Co²⁺ are respectively the pyrohotites FeS and CoS. The data illustrates that thermodynamic equilibrium has been established in the H₂S-controlled seawater of Saanich Inlet, and that equilibrium has not been established in the H₂S−O₂-coexisted seawater of Saanich Inlet. The lack of equilibrium in the H₂S−O₂-coexisted seawater is a result of the flushing or mixing of oxygenated seawater with anoxic water. The new species of trace metals are still in the processes of reduction and precipitation. Contribution No. 1428 from Institute of Oceanology, Academia Sinica     

Geochemical Characteristics and Sources of Some Chemical Components in Sediments of Zhuiiang（Pearl） River Estuary

Sediment cores with length of 25 - 45cm at 12 stations in Zhujiang(Pearl) River Estuary were sampled in summer of 1999. Chemical components (Al2O3 , Fe2O3, CaO, TiO2, Cu, Pb, Cr, Zn, Co, Ni, V, Ba, Sr and Y) and grain sizes were analyzed. Sediments in Zhujiang River Estuary are characterized by relatively coarse grain size. The grain sizes of the sediments in the area outside the estuary are relatively finer than those in the north part of the estuary but coarser than those in the middle of Lingdingyang and have a trend similar to the spatial distribution trend of some chemical components such as Fe2O3, Al2O3, TiO2, V, Cu, Ni, Zn and Y. This showed that grain size is an important factor that controls the spatial distribution and depth profile of chemical elements in the Zhujiang River Estuary. Frequent re-suspension, re-transportation and redistribution of settled sediment on estuary floor could be deduced from the spatial distributions and depth profiles of chemical components. Except for CaO and Sr, the chemical components always enrich at the west side of, in the middle of, and at the north side of, the estuary. Fe2O3, Al2O3, Ti, V, Cr, Ni, Zn, Cu and Y in Zhujiang River Estuary sediments mainly result from rock and soil weathering except that parts of Cr, Ni, Zn Cu and Y are anthropogenic. CaO and Sr in sediments originate from marine source. Although Co as well as Pb derives from anthropogenic sources, human activities related to Co might differ from the activities related to Pb.     

Heavy metal concentration and its evaluation in the organisms from Meizhou Bay

The present paper reports Zn,Cu,Pb,Cd,Ni,Fe,Mn and Co contents in the tissues of oyster,solen,red-tail prawn,sea eel and kelp,taken from Meizhou Bay(and analysed by flame atomicabsorption spectrophotometry after wet digestion)in June 1992,and also the concentration factors esti-mated from the mean metal concentrations in the organisms and water there.Heavy metal concentrationsin every species of the organisms followed the pattern:Fe,Mn,Cu,Zn>Pb,Cd,Ni,Co and in variousorganisms showed considerable variation.In general,levels of most of these metals were in the order:softtissues of the bivalves>the kelp>muscles of the red-tail prawn,the sea eel.The greatest concentrationof most metals was found in the gill or viscera of the sea eel,whereas the muscle tissues,in general,con-tained only low concentrations of them.The Cu,Zn concentration factors of the oyster were higher by1—2 orders of magnitude than that of the other organisms.The observed heavy metal levels were closeto those reported from various waters     

Interannual variability of transport and bifurcation of the North Equatorial Current in the tropical North Pacific Ocean

The relationship of the interannual variability of the transport and bifurcation latitude of the North Equatorial Current (NEC) to the El Ni o-Southern Oscillation (ENSO) is investigated. This is done through composite analysis of sea surface height (SSH) observed by satellite altimeter during October 1992-July 2009, and correspondingly derived sea surface geostrophic currents. During El Nio/La Ni a years, the SSH in the tropical North Pacific Ocean falls/rises, with maximum changes in the region 0-15°N, 130°E-160°E. The decrease/increase in SSH induces a cyclonic/anticyclonic anomaly in the western tropical gyre. The cyclonic/anticyclonic anomaly in the gyre results in an increase/decrease of NEC transport, and a northward/southward shift of the NEC bifurcation latitude near the Philippine coast. The variations are mainly in response to anomalous wind forcing in the west-central tropical North Pacific Ocean, related to ENSO events.     

Geochemical characteristics of heavy metals in riparian sediment pore water of Songhua River,Northeast China

This study reports the geochemical characteristics of zinc (Zn), copper (Cu), lead (Pb), nickel (Ni), mercury (Hg), iron (Fe), and manganese (Mn) in the riparian sediment pore water of the Songhua River, Northeast China. In total, 36 pore water samples and 18 surface water samples from three typical sections were collected and analyzed in June 2009. Cluster analysis of heavy metals was performed to analyze the pollution sources of the metals. Results showed that Hg concentrations in the pore water were greater than those in the surface water, indicating a potential ability of Hg release from riparian sediment system to river water. However, concentrations of Fe and Mn in the surface water were greater than those in the pore water, demonstrating that the microenvironments of riparian and riverbed sediment systems were quite different. Variations of Zn, Cu, Pb and Ni between the surface and the pore water were different in each section. Most metals had similar horizontal and profile distribution characteristics in the three sections except for Zn and Ni. Hg, Fe and Mn concentrations in the pore water increased gradually with the increase in horizontal distance from water body, in contrast to this, Cu decreased, and Pb presented a fluctuating trend. With the increase in depth, Pb and Fe, Cu and Mn showed the same trends, and Hg showed a variable trend. The above distribution characteristics could mainly be attributed to the properties and the interactions of metals, pH and oxidation-reduction conditions, and the complex pollution sources and hydrologic regime in history. The probable sources of metals include the historical and ongoing discharge of industrial wastewater, mining activities, sewage irrigation for agricultural production, and atmospheric deposition from coal-fired plants.     

Preliminary comparison of trace metals in coastal aerosols between Qingdao and Liverpool

Aerosol samples were collected at two coastal suburban stations, Qingdao （China） in 1995-1996 and Liverpool （U.K.） in 1995, respectively. The samples were analyzed to determine the concentrations of trace metals （Cr, Zn, Cu, Co, Ni, Pb, V, and Cd） as well as A1, Fe and Mn. Data were examined to understand the difference of trace metals in aerosols between coastal zones downwind the developing area （near the Yellow Sea） and developed region （near the Irish Sea）. The results show that most elements at Qingdao have levels 4-5 times higher than those at Liverpool, particularly for the crust-dominated elements （e.g. Al, Fe and Mn）. Moreover, the aerosol composition at Qingdao is higher in spring than in summer, underlying the influence of westerlies and local emissions in combination, whereas seasonal change of aerosol composition is not significant at Liverpool. The enrichment factors for the crustal source elements （EFcrust） at Liverpool are much higher than those at Qingdao. The contributions from the pollutant source （Rp） for some trace metals like Cu, Pb, Zn and Cd are 〉90% at Qingdao and Liverpool, suggesting overwhelming anthropogenic contributions to these metals. The contributions from crustal source （Re） for trace metals tend to increase with higher aerosol levels and Al concentration at Qingdao, indicating a good correlation between the crust-dominated component and the air mass. At Liverpool, the Rc values for trace metals are positively correlated with Al concentrations instead of with aerosol mass, suggesting that Al in aerosols represents the crustal component even though the aerosols come from different sources.     

辽宁金伯利岩地球化学特征

辽宁金伯利岩地质—地球化学研究结果表明,辽宁金伯利岩主元素丰度较世界金伯利岩的平均成分,显示富Ca、Al和贫K、Na、Mg、Si,碱度偏低;与南非、苏联和我国山东含金刚石金伯利岩相比,Fe 质偏高。辽宁金伯利岩含矿程度由富到贫,有 Fe、Mg 组分增高,Ca 质降低,微量元素多趋富集的总体变化趋势。辽南金伯利岩较辽北金伯利岩具有碱性程度相对偏高,V、Li、Rb、Nb、La、Sn、Mo、Cu、Pb、Zn、Ag、Ba、Cd、B、S、F 等元素相对富集,Co、Ni、Cr、Th、Bi、Au、As、Sb、Hg、Sr 等元素相对贫化的特点。二者的元素组合和相关特征有明显差别。辽南金伯利岩 Na、Ca、Mn 3元素的相关组合特征是富、贫(中)金刚石金伯利岩的一个地球化学标志。