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PT. Mitra Karya Utama (MKU) adalah salah satu industri pengecoran logam di Ceper yang menggunakan pasir cetak greensand sebagai bahan cetakan utama dalam pembuatan produk utamanya yaitu Silinder Linier. Produk ini dipesan oleh konsumen secara terus menerus (kontinyu) dan berkelanjutan. Kendala yang dihadapi, dalam proses produksi silinder linier ini mengalami kendala yang mempengaruhi hasil produk silinder linier. Cacat produk tersebut mengakibatkan kurang baik dan kurang berkwalitasnya produk tersebut dan mengakibatkan kerugian. Tujuan dari program ini adalah untuk mengatasi masalah produksi dan meningkatkan mutu produk. Program dilaksanakan dengan melakukan aplikasi penggunaan face sand pada cetakan produk. Penggunaan facesand dilakukan dengan membina operator industri mitra. Hasil yang diperolah adalah penerapan facesand pada cetakan mampu meningkatkan kuantitas produksi dan menurunkan rejek produk menjadi 10%.

The geochemical composition of glauconitic clasts is a provenance marker to distinguish the origin of gravity flows in sedimentary basins. Their geochemical variation is visible in major and trace elements composition, where the former can be visualized by element mapping of glauconitic clasts. By applying automated quantitative mineralogy on a Scanning Electron Microscope equipped with the ZEISS Mineralogic™ software platform, we developed a new way to visualize the element distribution in selected minerals, while masking out the other minerals simultaneously. This software applies energy dispersive spectroscopy spectrum deconvolution for each analysis point, therefore quantitative concentrations (wt%) of each element are determined for each pixel and visualized in the false-coloured element map with reproducible results for individual grains and zonations in these grains. The investigated glauconitic clasts were collected from eleven drill cores, covering a 1400 m-depth interval, and crosscutting four different gravity flow members. The clasts show three different trends: first, cores of glauconitic clasts show a variation of compositions that are mainly dependent on the conditions during their formation. This is most visible for Si and Al. Secondly, the composition of the glauconitic clasts changes with depth, their cores become first more, than less Fe-rich and more K-rich. This is probably an alteration effect, depending on temperature, and therefore mineral stability. And, thirdly, most glauconitic clasts are zoned, where rims are richer in Al and poorer in Fe and K. The visualization of the chemical variation in the glauconitic clasts proofs to be a useful tool to separate these conflicting element exchange processes.

We describe a new echinoid assemblage, composed of specimens of Bolbaster sp., Cyclaster danicus (Schlüter, 1897), Diplodetus vistulensis (Kongiel, 1950) and Linthia? sp. in a distinctive phosphatic preservation, from the so-called Greensand, a marly glauconitic sandstone horizon at the base of the Danian succession in the Kazimierz Dolny area (central Poland). This assemblage presumably is of early Danian age, with Cyclaster danicus occurring in the lower Danian of Denmark and southern Sweden. The specimens are preserved as internal moulds, composed of phosphatised glauconitic sandstone, occasionally with some test material adhering. The genesis of these moulds involved the following steps: (1) infilling of tests of dead echinoids with glauconitic sand,(2) penetration of the infills by coelobiotic deposit-feeding organisms that produced burrows along the inner test surface,(3) early-diagenetic cementation of infills by calcium phosphate,and (4) exhumation and intraformational reworking of specimens, leading to abrasion, fragmentation and loss of test material in some individuals. Co-occurring are unphosphatised moulds of Echinocorys ex gr. depressa (von Eichwald, 1866) and Pseudogibbaster cf. depressus (Kongiel in Kongiel and Matwiejewówna, 1937), which may represent a younger (middle to late Danian) assemblage. Additionally, the presence of derived late Maastrichtian echinoids, e.g., Temnocidaris (Stereocidaris) ex gr. herthae (Schlüter, 1892), Pleurosalenia bonissenti (Cotteau, 1866) and Hemicara pomeranum Schlüter, 1902, is confirmed for the Greensand, based on new material and re- examination of previously recorded specimens. In summary, members of three echinoid assemblages of different age and preservation occur together in the Greensand. Our results are compatible with former interpretations of this unit as a condensed, transgressive lag with mixed faunas of different age and provenance. However, they are incompatible with the hypothesis that phosphatised Danian fossils preserved in the Greensand are derived from a facies equivalent, now gone, of the lower Danian Cerithium Limestone in eastern Denmark, because all moulds are composed of phosphatised glauconitic sandstone that is utterly different from the calcareous dinocyst-dominated, fine crystalline matrix of the Cerithium Limestone. [ABSTRACT FROM AUTHOR]

To investigate the effects of preexisting flaws with different geometries, including flaw inclination angle and ligament angle on dynamic strength, deformation properties, and fracture evolution of rock materials, a series of dynamic impact tests were conducted on green sandstone specimens containing double elliptical flaws using a 75 mm diameter split Hopkinson pressure bar (SHPB) testing device with a high-speed camera recording in real time. The experimental results show that dynamic strength of specimens with different flaw angles is reduced between 5.91% and 39.92% but from 18.50% to 28.44% for specimens with different ligament angles, indicating that the effect of the flaw angle on the dynamic strength is more significant than that of the ligament angle. However, the dynamic deformation properties are influenced greatly by the ligament angle. Macroscale cracks mostly initiate at or near the flaw tips and then propagate in different paths with varying flaw geometries, leading to the ultimate failure in five typical modes based on the crack coalescence. Shear crack coalescence and tensile crack coalescence are identified through both macroscopic fracturing photos taken by the high-speed camera and microscopic surface morphology obtained by the scanning electron microscope (SEM). [ABSTRACT FROM AUTHOR]

The Upper Greensand Formation, mostly capped by the Chalk, crops out on the edges of a broad, dissected plateau in Devon, west Dorset and south Somerset and has an almost continuous outcrop that runs from the Isle of Purbeck to the Vale of Wardour in south Wiltshire. The Formation is well exposed in cliffs in east Devon and the Isle of Purbeck, but is poorly exposed inland. It comprises sandstones and calcarenites with laterally and stratigraphically variable amounts of carbonate cement, glauconite and chert. The sedimentology and palaeontology indicate deposition in marginal marine-shelf environments that were at times subject to strong tidal and wave-generated currents. The formation of the Upper Greensand successions in the region was influenced by penecontemporaneous movements on major fault zones, some of which are sited over E-W trending Variscan thrusts in the basement rocks and, locally, on minor faults. Comparison of the principal sedimentary breaks in the succession with the sequence boundaries derived from world-wide sea-level curves suggests that local tectonic events mask the effects of any eustatic changes in sea level. The preserved fauna is unevenly distributed, both laterally and stratigraphically. Bivalves, gastropods and echinoids are common at some horizons but are not age-diagnostic. Ammonites are common at a few stratigraphically narrowly defined horizons, but are rare or absent throughout most of the succession. As a result, the age of parts of the succession is still poorly known. [ABSTRACT FROM AUTHOR]

The Semri Group of the Vindhyan Supergroup contains widespread intrabasinal felsic volcanic rocks in the Porcellanite Formation formed during the early Mesoproterozoic. This widespread felsic volcanism was followed by the deposition of siliciclastic sedimentary rocks of the Kheinjua Formation containing the Olive Shale, Fawn Limestone, Glauconitic Sandstone members, the last one dominantly arkose and litharenite. The volcanic products resulting from volcanic activity during deposition of Porcellanite Formation were predominantly fine volcanic ash or dust that settled very slowly in the water column of the basin. The ranges of 28 elemental ratios for the Olive Shale and Glauconitic Sandstone members overlapped with those of the Porcellanite Shale Formation. The contemporaneous intermingling of the detrital input from volcanic products with the terrigenous detritus received by the basin from the Bundelkhand Craton in the north is reflected in the geochemical signatures. Various plots of elemental ratios and ternary plots for the siliciclastic rocks overlap those of the Porcellanite Shale Formation and Bundelkhand Tonalite‐trondhjemite‐granodiorite (TTG) suggesting that they might be the source rocks. The mixing of detritus from volcanic products was perhaps responsible for the widespread appearance of glauconite‐bearing sediments in the subsequent deposits. Glauconitization of detrital K‐feldspars, clay peloids, and volcanic lithic fragments is evident from the petrography. The shallow marine environment, slow sedimentation rates, elevated surface temperatures and mildly reducing conditions (CO2 got released from explosive volcanism) are considered as the favourable conditions for glauconitization, which prevailed within the Vindhyan Basin. Under these conditions the detrital input received as the result of previous volcanism during deposition of the porcellanite shale (glass, pumice lithic fragments, and feldspars) were transformed into clays such as illite and glauconite during the deposition of siliciclastic rocks of the Kheinjua Formation within the basin. [ABSTRACT FROM AUTHOR]

Wire and Arc Additive Manufacturing (WAAM) is a metal 3D printing technique based on robotic welding. This technique yields potential in decreasing material consumption due to its high material efficiency and freedom of shape. Empirical measurements of WAAM, using a deposition rate of 1 kg/h, were performed on site of MX3D. The measured power consumption per kg stainless steel is 2.72 kW, of which 1.74 is consumed by the welder, 0.44 by the robotic arm, and 0.54 by the ventilation. The material loss was 1.1%. A 98% argon 2% CO2 welding gas was used with a flow of 12 l/min. A cradle-to-gate Life Cycle Assessment (LCA) was performed. To give this assessment context, green sand casting and CNC milling were additionally assessed, through literature and databases. The purpose of this study is to develop insight into the environmental impact of WAAM. Results indicate that, in terms of total ReCiPe endpoints, the environmental impact of producing a kg of stainless steel 308 l product using WAAM is comparable to green sand casting. It equals CNC milling with a material utilization fraction of 0.75. Stainless steel is the main cause of environmental damage in all three techniques, emphasizing the importance of WAAM's mass reduction potential. When environmentally comparing the three techniques for fulfilling a certain function, optimized designs should be introduced for each manufacturing technique. Results can vary significantly based on product shape, function, materials, and process settings. [ABSTRACT FROM AUTHOR]

An evaluation studying the use of oxidation–reduction potential (ORP) for optimizing a 10,500 m³/d (2.8 MGD) oxidizing media filter (OMF) process treating Floridan groundwater containing between 1.6 and 1.8 mg/L sulfide has been completed. One year after placing the OMFs on-line, colored water complaints were reported within the municipal water system. It was determined that the filter beds required regeneration as they were insufficiently oxidized, and the media’s manganese dioxide coating was being released into the finished water. ORP, free chlorine residual, total manganese and turbidity measurements were recorded during filter run cycles before and after each regeneration event. Results showed that below 500 mV ORP was a more useful measurement for monitoring regeneration events within the media bed than chlorine residual which was not detectable. Results showed a significant increase in turbidity (>2 NTU) and total manganese (> 0.05 mg/L) when the ORP within the filter bed dropped below 400 mV. More frequent cycling of the filters was found to be an effective treatment option to maintain ORP values above 600 mV as an operational threshold. [ABSTRACT FROM AUTHOR]

At its maximum development in the type area on the Devon coast, the Upper Greensand Formation comprises up to 55 m of sandstones and calcarenites with laterally and stratigraphically variable amounts of carbonate cement, glauconite and chert that were deposited in fully marine, shallow-water environments. The formation is divided into three members, in ascending order the Foxmould, Whitecliff Chert and Bindon Sandstone, each of which is bounded by a prominent erosion surface that can be recognised throughout the western part of the Wessex Basin. The full thickness of the formation, up to 60 m, was formerly well exposed in cliffs in the Isle of Purbeck in the steeply dipping limb of the Purbeck Monocline. The upper part of the succession is highly condensed in comparison with the Devon succession and exhibits lateral variations over distances of hundreds of metres that are probably related to penecontemporaneous fault movements. Much of the fauna is not age-diagnostic with the result that the ages of parts of the succession are still poorly known. However, the Isle of Purbeck sections contain diverse ammonite faunas at a few stratigraphically well-defined levels that enable the succession to be correlated with that of east Devon and west Dorset. [ABSTRACT FROM AUTHOR]

Potassium is one of the important nutrients for healthy growth and development of plants. This article explores the possibility of extracting potassium from lean grade indigenous glauconitic sandstone, which is locked in the host matrix. Detail physico-chemical and mineralogical characterization of glauconitic sandstone collected from Guneri area of Kuchchh district, Gujarat (India) was carried out by X-ray diffraction (XRD), Scanning electron microscopy (SEM) followed by Energy-dispersive X-ray (EDX), X-ray fluorescence (XRF), Atomic absorption spectrometer (AAS) and conventional analytical tools. The major matrix of glauconite sample was found to contain 3.93% K 2 O, 10.75% Fe 2 O 3 , 4.41% Al 2 O 3 and 70.35% SiO 2 . The K 2 O content could be enriched from 3.93% to 5.52% by simple screening and rejection of +425 μm particles fraction. Chemical leaching of enriched fraction with hydrochloric acid (HCl) yields very low recovery (<12%) of potassium. Therefore, a combined reduction roasting-leaching method was developed to recover potassium chloride suitable for fertilizer application. The effects of roasting temperature, coke to glauconite ratio during roasting and various leaching parameters such as acid concentration, leaching time and temperature during dissolution of potash were studied. Parameters have been optimized to achieve more than 98% potassium recovery along with recovery of iron value as magnetite. [ABSTRACT FROM AUTHOR]

The study describes the degradation of inkjet ink at low frequency ultrasound (US) and greensand to compare their reactivity. Environmental sonochemistry is a rapidly growing area and an example of the advanced oxidation process (AOP) that deals with the destruction of organic species in aqueous solutions. Greensand is a granular material coated with a thin layer of manganese dioxide (MnO2) which is among the strongest natural oxidants. In our study magenta inkjet water-based printing ink was dissolved in distilled water and the solutions obtained after degradation were analysed in terms of total organic compound (TOC) and absorption curves in the visible spectra. Also used for the process monitoring was high performance liquid chromatography (HPLC). The efficiency of discoloration is significantly affected by the effluent pH. The efficiency of discolouration was higher when the pH of initial solution was 2 with respect to the initial solution pH of 5.5. In all solutions, irrespective of the initial pH value and the processing method the oxidation of polyhydric alcohols occurs. Although the decomposition is significant, surface peaks resulting from HPLC analysis are very small. Decolourization is closely related to the cleavage of the - C=C and -N=N- bonds, and oxidation of polyhydric alcohol to the formation of monosaccharides, carboxylic acids or other low molecular weight compounds with a lesser number of unsaturated double bonds. These compounds have low UV absorbance or they absorb below 200 nm and therefore their detection is impossible. Thus, the obtained total organic compound results indicate a small degree of mineralization. The effectiveness of the low-frequency ultrasound (20 kHz) oxidation is similar to the effectiveness of oxidation by greendsand. [ABSTRACT FROM AUTHOR]

The need for control of raw materials is critical to the success of iron casting production from greensand systems. The base silica sand is often overlooked with the main focus on bentonite additions.Carbonaceous additives can be considered a “necessary evil” to ensure a good surface fi nish and reduction in sand related surface defects. Other additives are used when systems get out of balance and these in turn add further to the complex nature of greensand systems.For castings requiring cores this becomes a bigger issue as many differing resin systems are employed for core production and these must be taken into consideration when controlling both the carbonaceous levels and the overall grading of the sand system. The twin effects on additional carbon and loss-on-ignition and overall sand grading need careful understanding and control. Various control methods are examined including traditional methods such as volatiles and loss-on-ignition along with bentonite determination methods and grading methods. Newer control methods such as total carbon are reviewed along with the overall package of testing and control methods. Various predictive methods are looked at as a control feature as well.The quality of additives and their role and more importantly their interaction is highlighted, as this is an area often neglected as foundrymen battle for success in consistent quality castings. Suggested in-coming control tests are discussed allied to additions at the mixer. Also reviewed is the interpretation of results and the action required to ensure control and more importantly consistent quality castings from greensand systems with the emphasis on the understanding and control of carbonaceous additive on casting performance.

Two Late Cenomanian - Early Turonian (C-T) intervals of the eastern part of the Kopet-Dagh basin, NE Iran have been investigated to evaluate the response of planktonic foraminifera to the geological event OAE2. The Gharesu and Taherabad sections with the thicknesses of 30 m and 22.5 m are composed of shale and marl interbedded with glauconitic sandstone. Three biozones Rotalipora cushmani, Whiteinella archaeocretacea and Helvetoglobotruncana helvetica were recognized based on study of planktonic foraminifera, in these sections. We observed the patterns of planktonic foraminiferal assemblage changes around the C-T boundary and divided this succession into several successive intervals. This study confirms that OAE2 was a long term event. A gradual perturbation in the study successions starts in the interval 1 with low abundance and diversity of planktonic foraminifera. An enhanced oxygen minimum zone (OMZ) occurs in the interval 3 which coincides with a temporary absence of planktonic foraminifera and sedimentation of framboidal pyrite. High diversity of planktonic foraminifera and appearance of new genera in the interval 5 indicate return of normal conditions to the basin. A significant short-term sea surface temperature cooling is also indicated by planktonic foraminiferal turnover and carbonate contents in the interval 2 which is comparable with other parts of the Tethys Ocean, Boreal sea and Atlantic region. [ABSTRACT FROM AUTHOR]

The Turonian successions of the southern Corbieres comprise three transgressive-regressive cycles in which ammonites occur in three intervals. The lowest comes from the glauconitic basal transgressive unit of the first cycle, and comprises 21 species, including Kamerunoceras douvillei (Pervinquiere, 1907), Kamerunoceras turoniense (d'Orbigny, 1850), Spathites (Jeanrogericeras) revelerianus (Courtiller, 1860), Spathites (Jeanrogericeras) combesi (d'Orbigny, 1856), Mammites nodosoides (Schluter, 1871), Mammites powelli Kennedy, Wright and Hancock, 1987, Fagesia tevestensis (Peron, 1896), Neoptychites cephalotus (Coutiller, 1860), Thomasites rollandi (Thomas and Peron, 1889), Wrightoceras wallsi Reyment, 1954, and Choffaticeras (Choffaticeras) quaasi (Peron, 1904). This is a Lower Turonian assemblage referred to the Mammites nodosoides Zone, although the possibility that elements from the preceding Fagesia catinus Zone are also present cannot be excluded. The fauna from the transgressive glauconitic interval of the succeeding cycle comprises nine species, including Romaniceras (Romaniceras) mexicanum Jones, 1938, Romaniceras (Yubariceras) ornatissimum (Stoliczka, 1864), Pseudotissotia galliennei (d'Orbigny, 1850), Collignoniceras woollgari (Mantell, 1822) sensu lato, Coilopoceras springeri Hyatt, 1903, and Eubostrychoceras (Eubostrychoceras) saxonicum (Schluter, 1872). They indicate the Middle Turonian Romaniceras (R.) mexicanum and R. (Y.) ornatissimum zones. The highest fauna, from the Marnes superieurs de Saint-Louis of the Saint-Louis syncline, is: Subprionocyclus sp. juv., Prionocyclus sp. and Worthoceras cf. rochatianum (d'Orbigny, 1850). The Subprionocyclus are minute individuals that resemble S. bravaisianus (d'Orbigny, 1841), and suggest the presence of the lower Upper Turonian bravaisianus Zone. [ABSTRACT FROM AUTHOR]

Thermal and chemical treatments were used to investigate the solubilization of potassium from verdete, a glauconitic rock. Fluxing agents were evaluated at distinct temperatures and proportions. Chemical dissolution of verdete was studied with increasing amounts of acids or bases at different temperatures and reaction times. In the calcination test, the presence of fluxing agents was critical to increasing the rock solubility, in addition to the effects of temperature and material ratios. The content of water-soluble K was 100, 100, 85, and 42% when using the salts LiCl, CaCl 2. 2H 2 O, Na 2 CO 3 , NaCl, respectively, as fluxing agents. The salts CaSO 4 , CaCO 3 and Ca 3 (PO 4 ) 2 were ineffective as fluxing agents. In the chemical treatments, the reaction with the base NaOH was more efficient than the acids to solubilize K. It was possible to solubilize up to 60% of K from verdete with 4.0 mol L − 1 NaOH, at 150 °C for 120 min. Among the acids, H 3 PO 4 was the most efficient, promoting solubilization of up to 42% K, with 4.0 mol L − 1 H 3 PO 4 , at 225 °C, for 120 min. When using the concentrated acid waste and shaking for 144 h, up to 75% of K could be solubilized from the rock. It was concluded that the heated treatments were most effective in solubilizing verdete, followed by the acid waste, which are processes required for the production of soluble potassium fertilizers from unconventional sources of low reactivity. [ABSTRACT FROM AUTHOR]

The Main Glauconite Bed (MGB) is a pelleted greensand located at Stone City Bluff on the south bank of the Brazos River in Burleson County, Texas. It was deposited during the Middle Eocene regional transgression on the Texas Gulf Coastal Plain. Stratigraphically it lies in the upper Stone City Member, Crockett Formation, Claiborne Group. Its mineralogy and geochemistry were examined in detail, and verdine facies minerals, predominantly odinite, were identified. Few glauconitic minerals were found in the green pelleted sediments of the MGB. Without detailed mineralogical work, glaucony facies minerals and verdine facies minerals are easily mistaken for one another. Their distinction has value in assessing paleoenvironments. In this study, several analytical techniques were employed to assess the mineralogy. X-ray diffraction of oriented and un-oriented clay samples indicated a clay mixture dominated by 7 and 14Å diffraction peaks. Unit cell calculations from XRD data for MGB pellets match the odinite-1M data base. Electron microprobe analyses (EMPA) from the average of 31 data points from clay pellets accompanied with Mössbauer analyses were used to calculate the structural formula which is that of odinite: Fe3+0.89 Mg0.45 Al0.67 Fe2+0.30 Ti0.01 Mn0.01) Σ = 2.33 (Si1.77 Al0.23) O5.00 (OH)4.00. QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) data provided mineral maps of quantitative proportions of the constituent clays. The verdine facies is a clay mineral facies associated with shallow marine shelf and lagoonal environments at tropical latitudes with iron influx from nearby runoff. Its depositional environment is well documented in modern nearshore locations. Recognition of verdine facies clays as the dominant constituent of the MGB clay pellets, rather than glaucony facies clays, allows for a more precise assessment of paleoenvironmental conditions. [ABSTRACT FROM AUTHOR]

The quality of cast products in green sand moulds is largely influenced by the mould properties, such as green compression strength, permeability, hardness and others, which depend on the input (process) parameters (that is, grain fineness number, percentage of clay, percentage of water and number of strokes). This paper presents multi-objective optimization of green sand mould system using evolutionary algorithms, such as genetic algorithm (GA) and particle swarm optimization (PSO). In this study, non-linear regression equations developed between the control factors (process parameters) and responses like green compression strength, permeability, hardness and bulk density have been considered for optimization utilizing GA and PSO. As the green sand mould system contains four objectives, an attempt is being made to form a single objective, after considering all the four individual objectives, to obtain a compromise solution, which satisfies all the four objectives. The results of this study show a good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

n optimization technique for process parameters of green sand casting of a cast iron differential housing cover based on the Taguchi parameter design approach is proposed in this paper. The process parameters considered are green strength, moisture content, pouring temperature, and mould hardness vertical and horizontal. An attempt has been made to obtain optimal level of the process parameters in order to yield the optimum quality characteristics of the cast iron differential housing cover castings. An orthogonal array, the signal-to-noise (S/N) ratio, and analysis of variance are used to analyze the effect of selected process parameters and their levels on the casting defects. The results indicate that the selected process parameters significantly affect the casting defects of grey cast iron differential housing cover castings. A confirmation run is used to verify the results, which indicated that this method is more efficient in determining the best casting parameters for differential housing cover. [ABSTRACT FROM AUTHOR]

Cirripede remains (Thoracica, Verrucomorpha), found associated with the mosasaur Prognathodon waiparaensis in glauconitic sands of the Late Cretaceous Conway Formation exposed along the Waipara River bank (mid-Canterbury, New Zealand), are identified as a new species, Verruca sauria sp. nov. On the basis of taphonomy, it is deduced that these verrucids grew on a postmortem accumulation of mosasaur bones under very quiescent conditions. The current amphitropical distribution of the earliest known verrucids, i.e. V. sauria sp. nov., V. prisca , V. pusilla and V. tasmanica , is rationalized in the light of Tethyan palaeogeography. [ABSTRACT FROM AUTHOR]

Abstract: Contamination of fresh groundwater is one of the environmental issues of Carbon Capture and Storage. We simulate with the reactive transport code TOUGHREACT the intrusion of CO2+ impurities from oxycombustion capture in a freshwater aquifer model based on a glauconitic sandstone aquifer. We choose an unfavorable scenario where the contaminant gas presents maximal contents in SO x , NO x and O2. Water quality changes after a 10 years intrusion are exposed. French quality standards in pH, Fe, Mn and sulphates concentrations for drinking water are reminded in the results for reference. Acidification and carbonation of water induces Fe- and Mn-bearing minerals dissolution that increases the concentration of these metals in water. Contamination by sulphates is due to the SO2 oxidation by O2, both of these components being carried by the contaminant gas. The vertical extent of contamination is enhanced by both the upward migration of gaseous CO2 and downward migration of dense carbonated water. The presence of SO2 and NO in the contaminant gas, even in very low concentrations, induces a negative local pH shift of 1 unit by comparison with a pure- CO2 contaminant gas. This pH shift has consequences on Fe and Mn release amplitude. The code does not allow realistic modelling of the fate of NO x in the aquifer. But we hypothesize this component to be oxidized by O2 into nitrite or nitrates (health-significant substances) that persist into the aquifer. Perspectives are addressed. [Copyright &y& Elsevier]

Bioturbated, glauconitic siltstones and sandstones are overlain by presumed Upper Triassic deposits at coastal exposures at Julegård on the south coast of Bornholm. These glauconitic deposits have not previously been dated. A 40Ar-39Ar dating of the glaucony gives an age of 493 ± 2 Ma suggesting the deposits belong to the Lower Cambrian Norretorp Member of the Læså Formation. The shallow marine deposits are strongly bioturbated, but only a single ichnoassociation is represented. The ichnogenus is referable to either Trichophycus Miller and Dyer, 1878 or Teichichnus Seilacher, 1955. Rare examples of Rusophycus Hall, 1852, probably trilobite trace fossils, are also represented. [ABSTRACT FROM AUTHOR]

Abstract: Green sandstones from the eastern part of the Bohemian Cretaceous Basin represent the traditional stone-cutting material used in the region of Eastern Bohemia since the 14th century. Sandstones of the Cenomanian age are shallow-water marine sediments dominated by pores over 5 µm in size. The green colour of the sandstone is caused by a content of glauconite with a high proportion of Fe 3+ in the structure, which is very stable under oxidative open-air conditions. A typical feature of this rock is its rapid absorption and humidity exchange rates between the rock and its immediate environment by vaporization as well as good thermal stability up to temperatures of approximately 550 °C. The rock is resistant to weathering if recommended conditions are observed when used in construction. The rock can be used in external architecture as well as in interiors of modern buildings. The data about the properties and stability of the rock published in this paper will serve as a basis for a historical–structural survey of buildings, for searches of authentic stone deposits for the preservation and restoration of buildings and as a recommendation for conservation work. [Copyright &y& Elsevier]

Abstract: 30 km southwest of Tunis, two thin flaky ‘Triassic’ intrusions underline the two flanks of the Atlasic anticline of Bir Afou. These evaporites are interbedded within the Clansayesian shales, and are under and overlain by glauconitic conglomeratic contacts. The ‘Triassic’ flakes, topic of our study, are sourced from the Bir Afou Triassic mass after a rapid pouring out during Late Aptian extensional tectonics. This structure corresponds, for us, to a ‘salt glacier’, similar to that one described at Ben Gasseur by Vila and al. [J.M. Vila, M. Ben Youssef, M. Chikhaoui, M. Ghanmi, Bull. Soc. géol. France 167 (1996) 235–246], which was subsequently folded during Lower Eocene times. Middle and Upper Eocene transgressive formations unconformably deposited on top of the Aptian anticlinal hinge. The major Late Miocene compressive phase is responsible for the present structures and that are superimposed onto the pre-existing ‘salt glacier’. This salifereous system extends the ‘salt glacier’ domain towards the eastern part of the Tunisian Atlas. To cite this article: M. Ben Chelbi et al., C. R. Geoscience 338 (2006). [Copyright &y& Elsevier]

A detailed study of the conodont distribution within the condensed carbonate beds around the boundary of Billingen and Volkhov Stages (Lower Ordovician, Arenig) in northwestern Russia confirms the presence of a continuous succession of conodont biownes recognized in contemporaneous sequences in Scandinavia. The Baltoniodus triangularis and Microzarkodina sp. A zones are reported for the first time from East Baltica, where carbonates of this interval underwent extensive bioturbation and are characterized by a number of closely spaced and distinctive glauconitic hardground surfaces. It has been revealed that the distribution of conodont elements around the hardground surfaces is strongly affected by bioturbation. [ABSTRACT FROM AUTHOR]