In memory of a scientist,colleague, and friend

Chronicle

In memory of a scientist, colleague, and friend     

Moscow and St. Petersburg, a sequence of capitals, a tale of two cities

From early modern times until the present, Russia (temporarily extended to the USSR) had two capital cities: Moscow and Petersburg. Moscow was the original capital, it was succeeded by Petersburg from the beginning of the 18th century. From the early 20th century onward Moscow again became the capital, but it became a different kind of capital at the end of the 20th century. The paper describes the evolution of the representation of the state function in the appearance of the capital cities by way of the state buildings, the monuments, the street names. In addition it analyses the fate of the former capitals (first Moscow, then Petersburg) in terms of their symbolic functions. Petersburg originated as a capital turned to the outside emphasizing Russia's European vocation, while Moscow was at first the inward looking capital city representing the distinctive spiritual values of Russia. Changes had to do with the changes in the nature of the successive political regimes and with the changing roles of the two cities within those regimes.     

Indo-Antarctica, Gondwanaland, and the distortion of a granulite belt

A detailed examination of a Gondwanaland re-assembly of Peninsular India and part of East Antarctica permits several conclusions to be drawn largely from data from the Indian coastal belt, which includes Ceylon. These are that original major granulite metamorphism probably occurred at about 2000 m.y., and that the sinuosity of the granulite belt, now split into two coastal belts, is a later distortion, outlined by anorthosite occurrences in India, which probably occurred between 720 and 450 m.y. Brief mention is made of the continuation of this belt into Madagascar, and of the problem of what lay between Western Australia and India in Gondwanaland.     

Characterisation of a Natural Quartz Crystal as a Reference Material for Microanalytical Determination of Ti,Al, Li,Fe, Mn,Ga and Ge

A natural smoky quartz crystal from Shandong province, China, was characterised by laser ablation ICP‐MS, electron probe microanalysis (EPMA) and solution ICP‐MS to determine the concentration of twenty‐four trace and ultra trace elements. Our main focus was on Ti quantification because of the increased use of this element for titanium‐in‐quartz (TitaniQ) thermobarometry. Pieces of a uniform growth zone of 9 mm thickness within the quartz crystal were analysed in four different LA‐ICP‐MS laboratories, three EPMA laboratories and one solution‐ICP‐MS laboratory. The results reveal reproducible concentrations of Ti (57 ± 4 μg g^?1), Al (154 ± 15 μg g^?1), Li (30 ± 2 μg g^?1), Fe (2.2 ± 0.3 μg g^?1), Mn (0.34 ± 0.04 μg g^?1), Ge (1.7 ± 0.2 μg g^?1) and Ga (0.020 ± 0.002 μg g^?1) and detectable, but less reproducible, concentrations of Be, B, Na, Cu, Zr, Sn and Pb. Concentrations of K, Ca, Sr, Mo, Ag, Sb, Ba and Au were below the limits of detection of all three techniques. The uncertainties on the average concentration determinations by multiple techniques and laboratories for Ti, Al, Li, Fe, Mn, Ga and Ge are low; hence, this quartz can serve as a reference material or a secondary reference material for microanalytical applications involving the quantification of trace elements in quartz.     

Precipitation of iron,manganese, zinc,and copper on clean,ceramic surfaces in a stream draining a polymetallic sulfide deposit

Acid-cleaned ceramic plates placed upstream and downstream from a Cu-Zn-Pb sulfide deposit (Magruder mine) developed a precipitate of Fe-Mn oxides in a 36-day period. Copper and Zn concentrations on the coated surface, normalized to surface area and ratios with Fe and/or Mn, are distinctly anomalous for a distance of 2 km downstream from the mine.The major source of metals in the coatings is interpreted to be groundwater percolating into the stream bed. Anomalous concentrations of Cu and Zn in groundwater from the Magruder mine area, due to oxidation of sulfide minerals, probably accounts for the anomaly identified on the ceramic plates.     

Synthesis, characterization and thermochemistry of a Pb-jarosite

The enthalpy of formation from the elements of a well-characterized synthetic Pb-jarosite sample corresponding to the chemical formula (H₃O)_0.74Pb_0.13Fe_2.92(SO₄)₂(OH)_5.76(H₂O)_0.24 was measured by high temperature oxide melt solution calorimetry. This value ( = −3695.9 ± 9.7 kJ/mol) is the first direct measurement of the heat of formation for a lead-containing jarosite. Comparison to the thermochemical properties of hydronium jarosite and plumbojarosite end-members strongly suggests the existence of a negative enthalpy of mixing possibly related to the nonrandom distribution of Pb²⁺ ions within the jarosite structure. Based on these considerations, the following thermodynamic data are proposed as the recommended values for the enthalpy of formation from the elements of the ideal stoichiometric plumbojarosite Pb_0.5Fe₃(SO₄)₂(OH)₆:  = −3118.1 ± 4.6 kJ/mol,  = −3603.6 ± 4.6 kJ/mol and S° = 376.6 ± 4.5 J/(mol K). These data should prove helpful for the calculation of phase diagrams of the Pb-Fe-SO₄-H₂O system and for estimating the solubility product of pure plumbojarosite. For illustration, the evolution of the estimated solubility product of ideal plumbojarosite as a function of temperature in the range 5-45 °C was computed (Log(K_sp) ranging from −24.3 to −26.2). An Eh-pH diagram is also presented.     

Steady-diffusion modelling of a reaction zone between a metamorphosed basic dyke and a marble from Hirao-dai, Fukuoka, Japan

A reaction zone between a metamorphosed basic dyke and marble at Hirao-dai, north Kyushu, Japan, consists of well-organized sequential zones of diopside, garnet and wollastonite; textures are characteristic of diffusion-controlled structures. The reaction zone formed during contact metamorphism associated with intrusion of a Cretaceous granodiorite at ∼300 MPa and 700 °C. The metamorphosed basic dyke consists of diopside, biotite and plagioclase ( X _Ab = 0.4–0.8), whereas the marble is almost pure calcite. The initial boundary between the dyke and the marble is probably located within the current diopside zone, as calcite occurs as remnants among diopside grains in areas close to the boundary with the garnet zone. This observation provides a criterion to judge the stability of the zonal sequence in our modelling. The formation of the reaction zone is attributed to a single-stage steady-state process with five overstepping reactions. CaO, MgO, FeO, SiO₂ and AlO_3/2 are the reaction-controlling components that are necessary to describe the growth of the reaction zone. An isochemical steady-diffusion model cannot reproduce the measured phase ratios of product minerals; this indicates open-system behaviour of the reaction zone. The choice of closure components is an essential task in the treatment of open-system modelling, together with determination of phase ratios (Ashworth & Birdi model) or estimation of boundary fluxes (Johnson & Carlson model). Of all the possible combinations of closure components, closure conditions for CaO and MgO provide the best results for both models. The stability of the zonal sequence is limited at relatively large values of L _SiSi/ L _CaCa. Similar results from the two models confirm their consistency under the same closure conditions.     

Characterization,modeling, and remediation of karst in a changing environment

This introductory editorial paper provides a review and prospective outlook of the achievements and challenges in karst research under a changing environment. A brief discussion of the past and future karst research has been focused on: (1) data and new technologies; (2) modeling of karst flow and reactive transport; (3) responses of karst hydrosystems to climate variability and changes across scales.     

On a Layer of Grossularite,Epidote and Calcite,Occurring at Kumush,Hoso,Sinkiang

正 In March,1944,while carrying on the geological reconnaissance in theHoso~1-Tokson~2 area,the writers had an opportunity of spending a fewdays in the vicinity of a small village named Kumush~3 (Fig.1) to study amoderately metamorphosed rock series.This region is characterized by     

Gas dynamics of a central collision of two galaxies: Merger, disruption, passage, and the formation of a new galaxy

Results of numerical simulations of a collision of the gaseous components of two identical disk galaxies during a head-on collision of the galaxies in the polar direction are presented. When the relative velocity of the galaxy collision is small, their gaseous components merge. At high relative velocities (100–500 km/s), the massive stellar components of the galaxies (M _g = 10⁹ M _⊙) pass through each other nearly freely, leaving behind the gaseous components, which are decelerated and heated by the collision. If the overall gaseous component of the colliding galaxies is able to cool to the virial temperature during the collision, a new galaxy forms. At velocities V ≥ 500 km/s, the gaseous component does not have time to cool, and the gas is scattered into intergalactic space, supplying it with heavy elements produced in supernovae in the colliding galaxies. High-velocity (V ≥ 100 km/s) collisions of identical low-mass galaxies (M _g ≤ 10⁹ M _⊙) whose mass is dominated by the mass of gas lead to the disruption of their stellar components. The overall gaseous component forms a new galaxy when V ≤ 500 km/s, and is scattered into intergalactic space if the velocity becomes higher than this. A galaxy collision increases the star-formation rates in the disk galaxies by nearly a factor of 100. Rotation of the colliding galaxies in the same direction increases the changes of the disruption of both the stellar and gaseous components of the galaxies. The merger of galaxies during their collision can explain the presence of gaseous disks rotating opposite to the rotation of the stellar component in some ordinary elliptical galaxies. Moreover, galaxy mergers can help explain the origin of a comparatively young stellar population in some elliptical galaxies.     

Controls on peat accumulation and depositional environments of a coal-bearing coastal plain succession of a pull-apart basin; a petrographic, geochemical and sedimentological study, Lower Jurassic, Denmark

The paralic, Lower-Middle Jurassic Bagå Formation of the Island of Bornholm, Denmark, was deposited in a fault-bounded, subsiding, pull-apart basin. The formation is up to 400 m thick and contains more than 50 coal seams. Twelve of these have been investigated petrographically and geochemically to provide basic information on the composition of the relatively unknown Jurassic coals. The peat-forming environments represented by the seams and the associated siliciclastic sediments are interpreted.The seams represent three types of environments with organic matter deposition. Peat accumulation occurred in low-lying areas situated between river channels in a coastal plain environment undergoing overall transgression. The coals have a relatively uniform, huminite-rich petrographic composition, indicating that the precursor mires were dominated by persistent, water-saturated and anoxic conditions. The swamps were probably occupied by a small-statured flora with cellulose-rich tissues. Significant bacterial activity in the peat swamps is suggested by an abundance of hopanes. Influence from marine water was not common but occurred occasionally. During peat accumulation, the depositional conditions were stable and quiet. The small thicknesses of the seams (8–57 cm thick) indicate relatively short periods of peat formation (average c. 2300 yr), due to continued base-level rise, controlled by subsidence, and an overall eustatic rise, causing repeated changes in the sedimentary regimes. The coal seams are of low rank and were buried to a depth of 1100–1200 m before uplift, due to Late Cretaceous-early Tertiary basin inversion and Neogene uplift.     

The geochemistry and mixing of leakage in a semi-confined aquifer at a municipal well field,Memphis, Tennessee,USA

The Memphis aquifer in southwestern Tennessee is confined to a semi-confined unconsolidated sand aquifer and is the primary municipal water source in the Memphis metropolitan area. Past studies have identified regions in the metropolitan area in which the overlying upper Claiborne confining unit lacks significant clay and provides a hydraulic connection between the shallow aquifer and the Memphis aquifer. In this study, major solute chemistry, ³H, and ³H/³He groundwater dating are used to investigate the extent and chemical effects of leakage through the confining unit to the Memphis aquifer in the vicinity of a municipal well field. The ³H/³He dates and geochemical modeling of the chemical data are used to constrain mixing fractions and the timing of modern recharge. Tritium activities of as much as 2.8 TU are observed in shallow production wells, but deeper production wells have ³H activities that approach the detection limit. Trends in water chemistry indicate vertical mixing in the aquifer of shallow Na–SO₄–Cl-rich water and deeper Ca–Mg–HCO₃-rich water. Water chemistry does not vary consistently with seasonal pumping, but ³H activity generally decreases during low use periods. Stable O and H isotopes show little variation and are not useful groundwater tracers for this study. The ³H-bearing, Na–SO₄–Cl-rich water is interpreted to reflect recharge of modern water through the upper Claiborne confining unit. The ³H/³He dates from 5 production wells indicate modern recharge, that infiltrated 15–20 a ago, is present in the shallow production wells. Geologic data and hydrologic boundary conditions suggest that the most likely source for continued leakage is a nearby stream, Nonconnah Creek. Geochemical reaction modeling using the NETPATH computer code suggests that proportions of shallow aquifer water leaking into the Memphis aquifer range from 6 to 32%. The ³H/³He dating and NETPATH modeling results correlate well, suggesting that these complementary analytical tools provide an effective means to evaluate proportions of modern water leaking into semi-confined aquifers. These results also indicate a need to carefully consider connections between surface water and semi-confined groundwater resources in wellhead protection programs.     

Energetics of anhydrite, barite, celestine, and anglesite: a high-temperature and differential scanning calorimetry study

The thermochemistry of anhydrous sulfates (anglesite, anhydrite, arcanite, barite, celestine) was investigated by high-temperature oxide melt calorimetry and differential scanning calorimetry. Complete retention and uniform speciation of sulfur in the solvent was documented by (a) chemical analyses of the solvent (3Na₂O · 4MoO₃) with dissolved sulfates, (b) Fourier transform infrared spectroscopy confirming the absence of sulfur species in the gases above the solvent, and (c) consistency of experimental determination of the enthalpy of drop solution of SO₃ in the solvent. Thus, the principal conclusion of this study is that high-temperature oxide melt calorimetry with 3Na₂O · 4MoO₃ solvent is a valid technique for measurement of enthalpies of formation of anhydrous sulfates. Enthalpies of formation (in kJ/mol) from the elements (ΔH_f^o) were determined for synthetic anhydrite (CaSO₄) (−1433.8 ± 3.2), celestine (SrSO₄) (−1452.1 ± 3.3), anglesite (PbSO₄) (−909.9 ± 3.4), and two natural barite (BaSO₄) samples (−1464.2 ± 3.7, −1464.9 ± 3.7). The heat capacity of anhydrite, barite, and celestine was measured between 245 and 1100 K, with low- and high-temperature Netzsch (DSC-404) differential scanning calorimeters. The results for each sample were fitted to a Haas-Fisher polynomial of the form C_p(245 K < T < 1100 K) = a + bT + cT⁻² + dT^−0.5 + eT². The coefficients of the equation are as follows: for anhydrite a = 409.7, b = −1.764 × 10⁻¹, c = 2.672 × 10⁶, d = −5.130 × 10³, e = 8.460 × 10⁻⁵; for barite, a = 230.5, b = −0.7395 × 10⁻¹, c = −1.170 × 10⁶, d = −1.587 × 10³, e = 4.784 × 10⁻⁵; and for celestine, a = 82.1, b = 0.8831 × 10⁻¹, c = −1.213 × 10⁶, d = 0.1890 × 10³, e = −1.449 × 10⁻⁵. The 95% confidence interval of the measured C_p varies from 1 to 2% of the measured value at low temperature up to 2 to 5% at high temperature. The measured thermochemical data improve or augment the thermodynamic database for anhydrous sulfates and highlight the remaining discrepancies.     

Geochemistry of Cu, Co, Ni, Zn, Cd and Cr in the surficial sediments of a tropical estuary, southwest coast of India: a granulometric approach

 Geochemical characteristics of six trace metals – Cu, Co, Ni, Zn, Cd and Cr – in the bulk sediment and sand, silt and clay fractions of a tropical estuary on the southwest coast of India have been studied and discussed. In bulk sediment, the trace metal concentration is controlled mainly by the textural composition of the sample. Mud, sandy mud and sandy silt register higher concentrations of trace metals than that in sand-dominant sediments. The granulometric partitioning studies also re-affirmed the role of particle size in enriching the trace metals. The silt and clay fractions exhibit 7–8 times the enrichment of Cu and Cd compared to that in sand. The enrichment factors of Zn, Cr, Ni and Co in the silt and clay fractions, compared to that in sand, are 5–6, 4–5, 2–5 and 2–3 times, respectively. The trace metals in the sand fraction, particularly Ni and Cr, exhibit strong positive correlation with the heavy mineral content of the samples. It clearly indicates a heavy mineral pathway to the trace metals in the sand fraction. Cu and Co in silt and clay fractions exhibit a marked decrease towards the high saline zones of the estuary. This is attributed to the desorption of Cu and Co from particulate phases during estuarine mixing. Contrary to Cu and Co, the content of Zn in the clay fraction shows a marginal increase towards the estuarine mouth. This could be explained by the influx of Zn-rich contaminant discharges from Zn-smelting industries located slightly north of the estuarine mouth. The released Zn will effectively be held in the lattices of the clay mineral montmorillonite, which also exhibits a marked increase towards the estuarine mouth. The anomalously high values of Cd in some places of the Central Vembanad estuary is attributed to the local pollution. Received: 10 July 1995 · Accepted: 3 June 1996     

Alluvial, eolian and lacustrine sedimentology of a Paleoproterozoic half-graben, Baker Lake Basin, Nunavut, Canada

The northeast-trending Baker Lake sub-basin was a volcanically active, half-graben during deposition of ca. 1.85–1.76 Ga Baker Lake Group. Drainage was oriented along transverse and axial directions with flow to playa lake and deeper perennial lacustrine depocentres. Basin marginal, streamflow-dominated alluvial fans were concentrated along the southern margin, and provided sediment from Archean crystalline basement rocks. These fed transverse gravel- and sand-bed braided streams. Alluvial dynamics were characterized by channel aggradation and abandonment. Abandoned channel belts were sites of floodplain and eolian deposition. Basin axial braided streams fed northeast and southwest to a depocentre near Christopher Island, where eolian, playa and lacustrine environments were intimately linked. Felsic minette flows were initially erupted from localized centres; contemporaneous sedimentary deposits typically contain minor volcaniclastic components that increase in abundance basinward. Voluminous and widespread younger minette flows prograded outward from volcanic centres contributing significant additional basin-infill.     

Evolution and deposits of a gravelly braid bar, Sagavanirktok River, Alaska

The evolution, migration and deposits of a gravelly braid bar in the Sagavanirktok River, northern Alaska, are described in unprecedented detail using annual aerial photographs, ground‐penetrating radar (GPR) profiles, trenches and cores. Compound braid bars in the Sagavanirktok River form by chute cut‐off of point bars and by growth of mid‐channel unit bars. Subsequent growth is primarily by accretion of unit bars onto their lateral and downstream margins. The upstream ends of braid bars may be sites of erosion or unit bar deposition. Compound braid bar deposits vary in thickness laterally and are thickest in medial sections and near cut banks. Compound bar deposits are typically composed of three to seven sets of simple large‐scale inclined strata, each simple set formed by a unit bar. The simple large‐scale strata contain medium‐scale cross‐strata (from dune migration) and planar strata (from migration of bedload sheets). The upstream and medial parts of compound braid bar deposits show very little vertical variation in grain size, but downstream and lateral margins tend to fine upwards. The deposits are mostly poorly sorted sands and gravels, although sands tend to be deposited at the top of the braid bar, and open‐framework gravels preferentially occur near the top and base of the braid bar. The patterns of braid bar growth and migration, and the nature of the deposits, described from the Sagavanirktok River are generally similar to other sandy and gravelly braided rivers, and consistent with the theoretical braid bar model of Bridge (1993).     

Mineralogy and petrology of a piemontite-bearing schist, western Otago, New Zealand

Abstract. Pink piemontite-spessartine-bearing and grey-green spessartine-bearing manganiferous quartzose schists derived from siliceous pelagites, and green quartzofeldspathic schists, are described from the greenschist facies of the Haast Schist terrane, near Arrow Junction, western Otago. Electron microprobe data are reported for sphene, spessartine-rich garnet, manganoan epidote, piemontite, tourmaline, phengitic muscovite, chlorite, albite, haematite, rutile, manganoan calcite and chalcopyrite. Metamorphism occurred at about 6.4kbar, 400°C. X_co2 was above the quartz-rutile-calcite-sphene buffer (X_co2± 0.02) throughout the recorded metamorphic history of the piemontite schists. It dropped from above to below this critical buffering value in a spessartine-rich schist and it was close to or below the buffering value in the quartzofeldspathic schists. Production of piemontite required high f_O2, believed to be inherited from MnO_x in the parent pelagite. Substantial loss of O₂ (e.g. minimum of 0.19% by weight in one rock) during diagenesis and/or metamorphism is inferred. In the grey-green schists this inhibited piemontite formation. Slight loss of O₂ and Ca²⁺ accompanied minor late-stage replacement of piemontite by second generation spessartine. Observed zoning and mineral replacements indicate rise of temperature, drop in pressure, or invasion by solutions of lower f_O2 and X_CO2 equilibrated with surrounding schists. The detailed chemistry of the minerals studied correlates with available Mn and with bulk-rock (Fe³⁺ x 100)/(Fe²⁺+ Fe³⁺). The oxidation ratio ranges from 24 in average green quartzofeldspathic schist, through 78 in average grey-green manganiferous quartzose schist, to almost 100 in some piemontite-bearing schists. As Fe²⁺ gives way to Fe³⁺, Mg/Fe ratios tend to rise in chlorite, phengite, tourmaline, spessartine, and calcite, Mn increases and Ti decreases in haematite, Mn increases in spessartine and calcite, and Fe increases in rutile. Available divalent cations are depleted relative to Al; chlorite is more aluminous, and phengite more paragonitic than in typical Haast schists.     

Distribution,behavior, and transport of inorganic and methylmercury in a high gradient stream

Concentrations of Hg remain elevated in physical and biological media of the South River (Virginia, USA), despite the cessation of the industrial use of Hg in its watershed nearly six decades ago, and physical characteristics that would not seem to favor Hg(II)-methylation. A 3-a study of inorganic Hg (IHg) and methylmercury (MeHg) was conducted in physical media (soil, sediment, surface water, porewater and soil/sediment extracts) to identify non-point sources, transport mechanisms, and potential controls on Hg(II)-methylation. Data collected from surface water and sediment indicate that the majority of the non-point sources of IHg to the South River are within the first 14 km downstream from the historic point source. Partitioning data indicate that particle bound IHg is introduced in this reach, releasing dissolved and colloidal bound IHg, which is transported downstream. Extraction experiments revealed that floodplain soils released a higher fraction of their IHg content in aqueous extractions than fine-grained sediment (FGS). Based on ultrafiltration [<5000 nominal molecular weight cutoff (NMWC)] the majority of soil IHg released was colloidal in nature, providing evidence for the continued evolution of IHg for Hg(II)-methylation from soil. Strong seasonal patterns in MeHg concentrations were observed in surface water and sediment. The highest concentrations of MeHg in surface water were observed at moderate temperatures, suggesting that other factors limit net Hg(II)-methylation. Seasonal changes in sediment organic content and the fraction of 1 N KOH-extractable THg were also observed and may be important factors in controlling net Hg(II)-methylation rates. Sulfate concentrations in surface water are low and the evidence suggests that Fe reduction may be an important Hg(II)-methylation process. The highest sediment MeHg concentrations were observed in habitats with large amounts of FGS, which are more prevalent in the upper half of the study area due to the lower hydrologic gradient and agricultural impacts. Past and present land use practices and other geomorphologic controls contribute to the erosion of banks and accumulation of fine-grained sediment in this section of the river, acting as sources of IHg.     

Geochemistry and origin of a black mudstone in a volcaniclastic environment, Ordovician Lower Rhyolitic Tuff Formation, North Wales, UK

Black mudstones in marine volcaniclastic environments have been interpreted both as non-volcanic ‘background’sedimentation and as fine grained vitric dust from the waning stages of primary volcanism. Although difficult to distinguish by standard petrographic techniques, differentiation between the two is crucial when attempting to determine sedimentation rates or to infer periods of volcanic quiescence. In the Ordovician Lower Rhyolitic Tuff Formation of North Wales such a fine grained black unit at Cwm Idwal is geochemically similar to an underlying rhyolite ash flow tuff. Its chemical index of alteration (CIA) is identical to that of the tuff. These data suggest that the black mudstone unit is a vitric tuff related to the underlying ash flow tuff. Use of a CIA in addition to trace element geochemistry should, in most cases, serve to distinguish tuffs from silicified mudstones.