Additional Provisional Elemental Values for LKSD-1, LKSD-2, LKSD-3, LKSD-4, STSD-1, STSD-2, STSD-3 and STSD-4

Provisional values related to element concentration derived from partial extractions as well as some additional total concentration data are reported for eight CCRMP sediment reference materials. These values are intended to supplement previously published data for these samples. The partial extractions for which data are reported include dilute HNO₃ - dilute HCl, concentrated HNO₃ -concentrated HCl and concentrated HNO₃ -concentrated HClO₄.     

Improvements in Digestion Protocols for Trace Element and Isotope Determinations in Stream and Lake Sediment Reference Materials (JSd-1, JSd-2, JSd-3, JLk-1 and LKSD-1)

Total dissolution is a critical step in geochemical analysis. Despite the number of published protocols, this issue still draws attention for sediment samples, which are particularly difficult to dissolve due to the common occurrence and high abundance of refractory phases such as zircon. We present tests of different chemical digestion procedures carried out on reference materials (RM) of stream (JSd-1, JSd-2 and JSd-3) and lake (JLk-1 and LKSD-1) sediments from the Geological Survey of Japan (GSJ) and the Canadian Certified Reference Material Programme (CCRPM). We demonstrate that the fusion technique is not appropriate for our studies as not all elements of interest were recovered and blank levels were too high to permit further Sr and Pb isotopic composition measurements. Similarly, conventional HF+HNO₃ dissolution methods were not efficient enough for detrital samples. Our preferred method involved using high pressure Teflon® vessel bombs in association with HClO₄. This protocol ensured a complete dissolution of the powder, as well as a complete recovery of trace elements. Moreover, blank levels were sufficiently low that Sr or Pb isotope compositions could be measured from the same mother solution. We also tested the homogeneity of RM powders by performing tests on various amount of powder.     

Three Marine Sediment Reference Samples: SDO-1, SDO-2 and SDO-3

The study of three marine sediments is the first in a series of reference samples to be developed for characterizing the bottom sediments of the Pacific Ocean and the Red Sea. The three samples were certified for their contents of major, minor and some trace elements. These values were assigned on the basis of statistical processing of the data obtained from an interlaboratory experiment conducted with the use of physical, physico-chemical and chemical methods of analysis. The Soviet, Czechoslovakian and Bulgarian laboratories took part in the interlaboratory experiment.     

High-Precision Trace Element Data for the USGS Reference Materials BCR-1, BCR-2, BHVO-1, BHVO-2, AGV-1, AGV-2, DTS-1, DTS-2, GSP-1 and GSP-2 by ID-TIMS and MIC-SSMS

Different batches of the new US Geological Survey (USGS) reference materials (RMs) BCR-2, BHVO-2, AGV-2, DTS-2 and GSP-2 and the original USGS RMs BCR-1, BHVO-1, AGV-1, DTS-1 and GSP-1 have been analysed by isotope dilution using thermal ionisation mass spectrometry (ID-TIMS) and by multi-ion counting spark source mass spectrometry (MIC-SSMS). The concentrations of K, Rb, Sr, Ba and the rare earth elements were determined with overall analytical uncertainties of better than 1% (ID-TIMS) and 3% (MIC-SSMS). The analyses of different aliquots and batches of BCR-2, BHVO-2, AGV-2 and GSP-2, respectively, agree within 1%, i.e. approximately the analytical uncertainties of the data. This indicates an homogeneous distribution of the trace elements in these RMs. Differences in element concentrations of up to 17% in different aliquots of the depleted RM DTS-2 are outside the analytical uncertainty of our data. They may be attributed to a slightly heterogeneous distribution of trace elements in this dunite sample. Our trace element data for BCR-2, BHVO-2, AGV-2 and GSP-2 agree within about 3% with preliminary reference values published by the USGS. They also agree within 1-6% with those of the original RMs BCR-1, BHVO-1, AGV-1 and GSP-1. Large compositional differences are found between DTS-2 and DTS-1, where the concentrations of K, Rb, Sr and the light REE differ by factors of 2 to 24.     

A Preliminary Study on the Preparation of Four Pacific Ocean Polymetallic Nodule and Sediment Reference Materials: GSPN-2, GSPN-3, GSMS-2 and GSMS-3

The research project for the preparation of two polymetallic nodule (GSPN-2, GSPN-3) and two marine sediment (GSMS-2, GSMS-3) reference materials was completed in 1996. The samples were collected from the Eastern and Central Pacific Ocean and prepared to less than 74 μm fine powder. The homogeneity of the materials was tested by X-ray fluorescence spectrometry. The relative standard deviations (RSD %) of measurements of selected elements in samples taken from thirty bottles selected at random were less than 0.5%. Thirty four laboratories worldwide participated in the collaborative analysis programme. The number of elements or constituents analysed was seventy nine for nodules and eighty one for sediments. Among those, sixty three elements were certified in each sample. The sum of major elements or components is 99.7% for GSPN-2, 99.5% for GSPN-3, 99.8% for GSMS-2 and 99.8% for GSMS-3.     

甘肃北山前红泉地区水系沉积物地球化学特征及找矿方向

前人在研究区开展过1∶20万水系沉积物测量及重砂测量,但受比例尺限制,异常面积过大,查证目标不够明确,找矿效果不佳。本次通过对前红泉地区开展1∶5万水系沉积物测量工作,初步总结了该区地球化学特征,根据元素组合特征、成矿地质条件等圈定出综合异常10处;在分析综合异常特征、异常检查情况及成矿潜力的基础上划分了成矿远景区4个,分别为受断裂和韧性剪切带控制的万岁山金成矿远景区、黑山头金多金属成矿远景区、与基性岩有关的帐房山铜钴镍成矿远景区及受酸性岩体内构造裂隙控制的红柳疙瘩钨成矿远景区;在成矿远景区内优选出找矿靶区4处,并提出了下一步找矿工作的建议。     

Sediment characteristics in the vicinity of the pulliam power plant,green bay,Wisconsin

Textural characteristics — mean, dispersion, and skewness — and heavy metal concentrations — Cr, Ni, Cu, Zn, Cd, and Hg — were determined for 41 bottom grab samples collected during July, 1973, at the mouth of the Fox River proximate to a coal-fired electric generating plant. The principal sediment types identified were very fine sand \((\bar x = 3.08\phi )\) and medium silt \((\bar x = 5.54\phi )\) . Irregular sediment distribution patterns along the western bank of the river reflect the complex interaction of the river currents and the orthogonally injected thermal effluent. Beyond the influence of the discharge plume, a more regular trend of sediment dispersal was identified. Sedimentary processes operative within this shallow environment are subject to considerable modification by wind-induced turbulence. The levels of Cr, Cu, Zn, and Cd were two to four times more concentrated in the Recent sediments than in the underlying glaciolacustrine deposits of red (Valders) clay. Ni concentrations were generally low while Hg was 15 to 35 times higher than background levels. Heavy metals were more concentrated in the fine-grained sediments of the river and shipping channel than in the coarser fractions along the river banks and nearshore environments of the lower Bay. The thermal effluent of the power plant has local but significant physical effects on the sediments in the vicinity of the discharge outlet. The chemical character of the sediments is established principally through upstream sources in the Fox River.     

DETERMINATION OF MINOR AND TRACE ELEMENTS IN FOUR CANADIAN IRON FORMATION STANDARD SAMPLES FER-1, FER-2, FER-3 AND FER-4 BY INAA AND ICP-MS

Analytical data on samples FeR-1, FeR-2, FeR-3 and FeR-4 obtained by instrumental neutron activation analysis and by inductively coupled plasma mass spectrometry are presented. The applied methods are described, and the analytical problems associated with their use are discussed. The accuracy of the two methods is demonstrated by comparing the results with the recommended values of the iron formation reference sample, IF-G. For the four FeR samples a set of values summarizing all data obtained by the two analytical methods is also given.     

Sediment–water interaction, acidity and other water quality parameters in a subtropical setting, Pimpama River, southeast Queensland

 The geological setting and landuse activities of the Pimpama River catchment are typical for many drainage systems in southeast Queensland. The river originates in coastal ranges of Late Paleozoic age, crosses a floodplain developed during the Late Pleistocene-Holocene sea-level fluctuations and flows into the southern part of the Moreton Bay. The formation of sedimentary pyrite associated with the mid-Holocene transgression is an important feature of this coastal setting. The oxidation and hydrolysis of pyrite and the consequent production of sulfuric acid are controlled by the amount and seasonality of rainfall and influenced locally by landuse activities. The acid production and the leaching of dissolved metals from river alluvium and estuarine sediments impact substantially on land and aquatic habitats. The water quality of the Pimpama River and its tributaries reflects the lithology of the bedrock and can vary largely depending on season, tidal regimes, sediment lithology, local topography and agricultural activities. Monitoring of river water for several seasons revealed four types of events, each with a different response in terms of water quality: (a) occasional showers during the dry season cause low pH and high amounts of dissolved metals in the water, (b) the first heavy rain of the wet season can produce very toxic conditions (low pH and high concentrations of metals) that can result in a fish kill, (c) towards the end of the wet season, prolonged flushing of pyrite oxidation products leads to short-term recovery of the aquatic system (neutral pH and lower amounts of dissolved metals in the water) and (d) a flood event can produce low pH, salinity and high concentrations of metals, which can represent lethal conditions for aquatic life. Assessment of saturation indexes for representative weathering and oxidation products such as clays, goethite, gibbsite and jarosite shows that these mineral phases can precipitate only when the water reaches neutral pH. Received: 21 September 1998 · Accepted: 1 December 1998     

Cd, Gd and Sm Concentrations in BCR-1, BHVO-1, BIR-1, DNC-1, MAG-1, PCC-1 and W-2 by Isotope Dilution Thermal Ionisation Mass Spectrometry

Cadmium, gadolinium and samarium concentrations were determined in seven geochemical reference materials by isotope dilution thermal ionisation mass spectrometry. The results for all three elements in BCR-1 are in excellent agreement with the compiled values as well as the literature values dete-mined by isotope dilution mass spectrometry. The agreement with compiled values on the other material is generally good except for Cd where the values for BHVO-1, BIR-1, DNC-1 and W-2 need to be revised.     

Reactive Transport Modeling of Subaqueous Sediment Caps and Implications for the Long-Term Fate of Arsenic, Mercury, and Methylmercury

A 1-D biogeochemical reactive transport model with a full set of equilibrium and kinetic biogeochemical reactions was developed to simulate the fate and transport of arsenic and mercury in subaqueous sediment caps. Model simulations (50?years) were performed for freshwater and estuarine scenarios with an anaerobic porewater and either a diffusion-only or a diffusion plus 0.1-m/year upward advective flux through the cap. A biological habitat layer in the top 0.15?m of the cap was simulated with the addition of organic carbon. For arsenic, the generation of sulfate-reducing conditions limits the formation of iron oxide phases available for adsorption. As a result, subaqueous sediment caps may be relatively ineffective for mitigating contaminant arsenic migration when influent concentrations are high and sorption capacity is insufficient. For mercury, sulfate reduction promotes the precipitation of metacinnabar (HgS) below the habitat layer, and associated fluxes across the sediment–water interface are low. As such, cap thickness is a key design parameter that can be adjusted to control the depth below the sediment–water interface at which mercury sulfide precipitates. The highest dissolved methylmercury concentrations occur in the habitat layer in estuarine environments under conditions of advecting porewater, but the highest sediment concentrations are predicted to occur in freshwater environments due to sorption on sediment organic matter. Site-specific reactive transport simulations are a powerful tool for identifying the major controls on sediment- and porewater-contaminant arsenic and mercury concentrations that result from coupling between physical conditions and biologically mediated chemical reactions.     

Speciation and Mobility of Selected Trace Metals (As, Cu, Mn, Pb and Zn) in Sediment with Depth in Cam River-Mouth, Haiphong, Vietnam

The speciation and mobility of some selected trace metals (As, Cu, Mn, Pb and Zn) in sediments with depth was investigated in the Cam River-mouth (Vietnam) by collecting sediment cores and analysing porewater and sediment composition, complemented with single (ammonium-EDTA) and sequential (BCR 3-step) extractions and mineralogical analysis (XRD). All trace metals show overall decreasing trends with depth in porewater as a result of anthropogenic input in upper sediment layers. High porewater concentrations of As, Mn and Pb in oxic and suboxic sediment layers may result in groundwater pollution. Sediment-bound Pb and Mn dominate in the reducible and the acid-soluble fraction, respectively, while Cu and Zn distribute rather evenly between four extracted fractions. The porewater metal speciation, as predicted by a geochemical model Visual MINTEQ version 3.0, indicates that the toxicity of Cu, Mn, Pb and Zn (presented by the proportions of free metal ions) decreases with depth, while the toxicity of As increases when As(III) becomes more abundant. The dissolved concentrations of trace metals are not only controlled by the precipitation/dissolution of discrete hydroxide/oxide, carbonate and phosphate minerals, but also by sorption processes on major sorbents (i.e. As on goethite, and Mn and Zn on calcite and dolomite). Sulphide minerals do not show any control even in the anoxic zone most likely because of the low concentration of sulphur.     

Elemental Concentrations in Japanese Silicate Rock Standards JA-1, JR-1 and JB-2

Data on three Japanese geochemical reference samples (JR-1, JA-1, and JB-2) are presented. Ten major and thirty-five trace element concentrations were determined using x-ray fluorescence, instrumental thermal neutron activation, thermal neutron capture prompt gamma-ray spectrometry, delayed neutron assay, automated thermal neutron activation analysis, inductively coupled plasma emission, atomic absorption, and ion selective electrode. Good agreement between the various methods and with recent literature values were obtained using error weighted mean concentrations for the samples.     

Trace element concentrations in the isotopically unique Allende inclusion,EK 1-4-1

Concentrations of rare-earth elements (REE), Sc, Fe, Co, Cr, Na and Ir in the bulk sample and mineral separates of the isotopically unique Allende inclusion, EK 1-4-1, were determined by instrumental neutron activation analysis. REE concentrations were also determined by mass-spectrometric isotope dilution for two density separates.The inclusion showed enrichment of light REE over heavy REE with a positive Yb anomaly, thus showing a tendency to resemble group II fine-grained inclusions in REE abundances, although EK 1-4-1 is a coarse-grained inclusion. High Cr concentrations also indicate group II affinity. However, high Ir (6 ppm) and Sc (105 ppm), and low FeO (1.80%), and Co (13.8 ppm) concentrations in the bulk sample and low Na concentrations in mineral separates show group I affinity.Between melilite and pyroxene fractions, the same samples in which mass-fractionated O isotope ratios were observed (Clayton and Mayeda, 1977), REE, Sc, Co and Fe showed distributions which are substantially different from those observed for “ordinary” Allende type B inclusions. These two minerals do not appear to be in equilibrium with respect to trace element distributions.The results indicate that the isotopically unique EK 1-4-1 is also unusual in its elemental abundances and distributions.     

Sediment trace metals and PCB input history in Lake Anna, Virginia, USA

Damming of the North Anna River in 1972 created Lake Anna, a cooling water source for the Dominion nuclear power plant as well as a popular recreation site in Spotsylvania and Orange counties, Virginia, USA. Previously dated (210-Pb) sediment cores from seven locations within the lake and three locations in the adjoining Waste Heat Treatment Facilities (WHTF) were analyzed for trace metals (Al, Ba, Zn, Cd, Cu, Fe, Mn and Pb) and polychlorinated biphenyls (PCBs) to examine the environmental evolution of the reservoir system. The reservoir has a history of mining activities in its watershed and unusually elevated concentrations of PCBs were found in fish tissues from previous studies. Therefore, dated sediment cores provided the framework for both the temporal and spatial analysis of possible sources and flux histories for both trace metals and PCBs. The trace metals results suggest that, though the upper reaches are relatively less impacted, the old mine tailings from the now ceased mining activities in the watershed of Contrary Creek tributary continue to dominate the sediment chemistry of the lower portion of the lake basin, signified by sediment enrichment of Pb, Cd, Cu, and Zn. Lagoon-2 of the WHTF also seems to be receiving unusually high loadings of Cd (12.5 ± 1.07 μg/g) that is probably associated with waste materials from the nuclear power plant that maintains the lagoons. PCB sediment concentrations were relatively low in the lower sections of the basins with values typically being <3.5 ng/g. The upper reaches of the basin had several PCB hotspots, with the surface sediments of Terry’s Run tributary having values as high as 53.13 ng/g. The spatial distribution of PCBs seems to suggest the upper reaches of the basin as the probable source, with the unusually high concentrations near bridges suggesting a possible link between the PCBs and old bridge fill materials. The oldest lacustrine sediments also had relatively high trace metals and PCB values signifying a probable role of soil disruption and sediment reconcentration during reservoir construction.     

The Preparation of Marine Geological Certified Reference Materials - Polymetallic Nodule GSPN-1 and Marine Sediment GSMS-1 from the Central Pacific Ocean*

This report describes the location, collection, preparation, homogeneity testing, analysis, data-processing and assignment of certified values of a polymetallic nodule (GSPN-1) and marine sediment (GSMS-1). Materials used in the preparation of these reference materials were collected in 1986 and 1987 from the central Pacific Ocean, by the Chinese Ministry of Geology and Mineral Resources (MGMR). A total of fifty one recommended element concentrations and five proposed concentrations are reported for GSPN-1. For GSMS-1, a total of fifty recommended and seven proposed values are presented.     

High pressure phase transformations in the joins Mg2SiO4-Ca2SiO4 and MgO-CaSiO3

High pressure phase transformations for all the mineral phases along the joins Mg₂SiO₄-Ca₂-SiO₄ and MgO-CaSiO₃ in the system MgO-CaO-SiO₂ were investigated in the pressure range between 100 and 300 kbar at about 1,000 °C, by means of the technique involving a diamond-anvil press coupled with laser heating. In addition to the four end-members, there are three stable intermediate mineral components in these two joins. Phase behaviour of all the end-member components at high pressure have been reported earlier and are reviewed here. Results of this study reveal that the three intermediate components are all unstable relative to the end-members at pressures greater than 200 kbar. Ultimately, monticellite (CaMgSiO₄) decomposes into CaSiO₃ (perovskite-type)+MgO; merwinite (Ca₃MgSi₂O₈) decomposes into Ca₂SiO₄(K₂NiF₄-type)+CaSiO₃ (perovskite-type)+MgO; and akermanite (Ca₂MgSi₂O₇) decomposes into CaSiO₃ (perovskite-type)+MgO. Note that the decomposition reactions of all phases studied here result in the formation of MgO. Intermediate Ca-Mg silicates transform to pure Ca-silicates plus MgO, while pure Mg₂SiO₄ transforms to MgSiO₃+MgO.     

The nature of the chemical bonds in sulvanite,Cu3VS4 1

Summary It is shown that a completely tetrahedral structure for Cu₃VS₄ would be unstable because of a large residual electric charge on the vanadium atom. The observed structure of sulvanite places six copper atoms, as well as four sulfur atoms, within bonding distance of each vanadium atom. The consideration of alternative valence-bond structures that are compatible with the electroneutrality principle (atomic charges restricted to the range between–1 and +1) leads to the bond numbers 0.50 for Cu–S and 0.29 for V–Cu, with 1.00 assumed for V–S. These bond numbers correspond reasonably well with the observed bond lengths and with electroneutrality (charges-0.27 for Cu, +0.06 for V, +0.19 for S). The bond angles at the sulfur atom indicate some bond-bending strain, estimated at 0.85 kcal mole^–1 per sulfur atom. This study of the sulvanite structure thus provides an explanation of the concentration of the four bonds formed by the sulfur atom into a small solid angle on one side of the atom.

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Zusammenfassung Es wird gezeigt, daß eine Struktur mit durchgehend tetraedrischer Koordination für Cu₃VS₄ wegen der großen Restladung des Vanadiumatoms instabil wäre. In der beobachteten Struktur des Sulvanites liegen sowohl vier Schwefelatome wie sechs Kupferatome im Bindungsabstand zu jedem Vanadiumatom. Die Betrachtung anderer kovalenter Strukturen, die mit dem Elektroneutralitäts-Prinzip (Atomladungen auf den Bereich zwischen –1 und +1 beschränkt) verträglich sind, führt auf Bindungszahlen 0,50 für Cu–S und 0.29 für V–Cu, wenn 1,00 für V–S angenommen wird. Diese Bindungszahlen entsprechen den beobachteten Bindungslängen und der Elektroneutralität (Ladungen –0,27 für Cu, +0,06 für V, +0,19 für S) ziemlich gut. Die Bindungswinkel am Schwefelatom deuten auf eine gewisse Spannung durch Verbiegung der Bindungen hin, die auf 0,85 kcal·mol^–1 pro Schwefelatom geschätzt wird. Diese Untersuchung der Sulvanitstruktur liefert so eine Erklärung für die Konzentration der vier von Schwefel ausgehenden Bindungen in einem kleinen räumlichen Winkelbereich an einer Seite des Atoms.

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With 1 Figure

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Dedicated to ProfessorF. Machatschki on the occasion of his 70th birthday.     

Sediment characteristics and water physicochemical parameters of the Lysimachia Lake, Western Greece

In the present paper, we present the sedimentological characteristics and the water physicochemical parameters of Lysimachia Lake, which is one of the most important lakes of Western Greece, as it is protected by international conventions and is listed in the Natura 2000 European Network. Sedimentological analysis involved grain size analyses, moment measures, total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) measurements, as well as determination of the clay minerals content. Water physicochemical parameters such as pH, temperature, conductivity and dissolved oxygen were measured in situ with portable equipment, while nutrients such as nitrates, nitrites, phosphates and ammonium ions, as well as TOC and TN were analyzed in a time period of 1 year seasonal monitoring. Geographical distribution of grain size and geochemical parameters indicated a clear partition in the northern and southern parts of the lake. This phenomenon can related to the discharging of a channel into the lake, the discharging of sewage effluents from Agrinio city during the last years as well as the type of clay minerals distribution. Clay minerals analyses indicated that smectite predominates in the northern part of the lake, whereas chlorite is more abundant in the southern parts. This explain the higher amounts of TOC and TN observed in the northern part of the lake and can be correlated with the higher external surface and adsorption capacity of minerals in the smectite-rich sediments. The four seasons monitoring of water physicochemical parameters indicates a relatively higher values of TOC and TN in the northern part of the lake, while nutrient concentrations indicate a uniform geographical distribution along the lake.     

Decadal-Timescale Estuarine Geomorphic Change Under Future Scenarios of Climate and Sediment Supply

Future estuarine geomorphic change, in response to climate change, sea-level rise, and watershed sediment supply, may govern ecological function, navigation, and water quality. We estimated geomorphic changes in Suisun Bay, CA, under four scenarios using a tidal-timescale hydrodynamic/sediment transport model. Computational expense and data needs were reduced using the morphological hydrograph concept and the morphological acceleration factor. The four scenarios included (1) present-day conditions; (2) sea-level rise and freshwater flow changes of 2030; (3) sea-level rise and decreased watershed sediment supply of 2030; and (4) sea-level rise, freshwater flow changes, and decreased watershed sediment supply of 2030. Sea-level rise increased water levels thereby reducing wave-induced bottom shear stress and sediment redistribution during the wind-wave season. Decreased watershed sediment supply reduced net deposition within the estuary, while minor changes in freshwater flow timing and magnitude induced the smallest overall effect. In all future scenarios, net deposition in the entire estuary and in the shallowest areas did not keep pace with sea-level rise, suggesting that intertidal and wetland areas may struggle to maintain elevation. Tidal-timescale simulations using future conditions were also used to infer changes in optical depth: though sea-level rise acts to decrease mean light irradiance, decreased suspended-sediment concentrations increase irradiance, yielding small changes in optical depth. The modeling results also assisted with the development of a dimensionless estuarine geomorphic number representing the ratio of potential sediment import forces to sediment export forces; we found the number to be linearly related to relative geomorphic change in Suisun Bay. The methods implemented here are widely applicable to evaluating future scenarios of estuarine change over decadal timescales.