Die Entgiftung von zyanidhaltigen Abwässern durch Oxydation mit Hypochlorit

Ohne Zusammenfassung Mitteilung Nr. 84     

40Ar/39Ar dating of the long range dikes,Newfoundland

Stepwise outgassing experiments were performed on eleven whole rock samples from a sequence of diabase dikes from the Great Northern Peninsula. Gas released at high temperatures (> ? 925–950°C) was consistently characterized by anomalously high apparent ages. These are attributed to the release of excess radiogenic argon, gas which probably resides in the mineral augite. At temperatures below ? 700°C, a wide range in apparent age was observed. On the other hand, the medium temperature region (? 700–950°C) is characterized by a relatively small range in apparent age. Data points corresponding to this region are rather well correlated in an isochron-type diagram; the slope of the best-fitting straight line corresponds to an aget = 605 ± 10m.y. We suggest that the outgassing of unaltered plagioclase is dominating the age spectra in this temperature interval. Consequently, we take 605 ± 10 m.y. as the time of emplacement of the Long Range dike swarm. This event may have marked the opening of a proto-Atlantic Ocean. The Acadian Orogeny (perhaps the ocean-closing event ? 380 m.y. ago) appears to be recorded in the low-medium temperature regions in the cases of two rather extensively altered samples.     

华北地区石炭－二叠系煤系地层和轻质油关系研究

对华北地区石炭－二叠系、下第三系、中上元古界沉积物和油样的低环萜烷参数用因子分析方法进行油源对比，表明石炭－二叠系部分样品与该区轻质油的关系密切。进一步分析这套地层的有机地球化学特征后，提出壳质组含量和成熟度是决定石炭－二叠系能否生成轻质油的主要因素，并提出该区煤系地层生成轻质油的成熟度下限是镜质组反射率Ｒ０为１．１％。     

Quantifying Organization of Atmospheric Turbulent Eddy Motion Using Nonlinear Time Series Analysis

Using three methods from nonlinear dynamics, we contrast the level of organization inthe vertical wind velocity (w) time series collected in the atmospheric surface layer(ASL) and the canopy sublayer (CSL) for a wide range of atmospheric stability ()conditions. The nonlinear methods applied include a modified Shannon entropy, waveletthresholding, and mutual information content. Time series measurements collected overa pine forest, a hardwood forest, a grass-covered forest clearing, and a bare soil, desertsurface were used for this purpose. The results from applying all three nonlinear timeseries measures suggest that w in the CSL is more organized than that in the ASL, and that as the flows in both layers evolve from near-neutral to near-convective conditions, the level of organization increases. Furthermore, we found that the degree of organization in w associated with changes in is more significant than the transition from CSL to ASL.     

Climatic control on river discharge simulations,Zackenberg River drainage basin,northeast Greenland

A spatially distributed, physically based, hydrologic modeling system (MIKE SHE) was applied to quantify intra‐ and inter‐annual discharge from the snow and glacierized Zackenberg River drainage basin (512 km²; 20% glacier cover) in northeast Greenland. Evolution of snow accumulation, distribution by wind‐blown snow, blowing‐snow sublimation, and snow and ice surface melt were simulated by a spatially distributed, physically based, snow‐evolution modelling system (SnowModel) and used as input to MIKE SHE. Discharge simulations were performed for three periods 1997–2001 (calibration period), 2001–2005 (validation period), and 2071–2100 (scenario period). The combination of SnowModel and MIKE SHE shows promising results; the timing and magnitude of simulated discharge were generally in accordance with observations (R² = 0·58); however, discrepancies between simulated and observed discharge hydrographs do occur (maximum daily difference up to 44·6 m³ s^?1 and up to 9% difference between observed and simulated cumulative discharge). The model does not perform well when a sudden outburst of glacial dammed water occurs, like the 2005 extreme flood event. The modelling study showed that soil processes related to yearly change in active layer depth and glacial processes (such as changes in yearly glacier area, seasonal changes in the internal glacier drainage system, and the sudden release of glacial bulk water storage) need to be determined, for example, from field studies and incorporated in the models before basin runoff can be quantified more precisely. The SnowModel and MIKE SHE model only include first‐order effects of climate change. For the period 2071–2100, future IPCC A2 and B2 climate scenarios based on the HIRHAM regional climate model and HadCM3 atmosphere–ocean general circulation model simulations indicated a mean annual Zackenberg runoff about 1·5 orders of magnitude greater (around 650 mmWE year^?1) than from today 1997–2005 (around 430 mmWE year^?1), mainly based on changes in negative glacier net mass balance. Copyright © 2007 John Wiley & Sons, Ltd.     

A systematic approach to the input determination for neural network rainfall–runoff models

Input determination has a great influence on the performance of artificial neural network (ANN) rainfall–runoff models. To improve the performance of ANN models, a systematic approach to the input determination for ANN models is proposed. In the proposed approach, the irrelevant inputs are removed. Then an adequate ANN model, which only includes highly relevant inputs, is constructed. Unlike the trial‐and‐error procedure, the proposed approach is more systematic and avoids unnecessary trials. To demonstrate the effectiveness of the proposed approach, an application to actual typhoon events is presented. The results show that the proposed ANN model, which is constructed by the proposed approach, has advantages over those obtained by the trial‐and‐error procedure. The proposed ANN model has a simpler architecture, needs less training time, and performs better. The proposed ANN model is recommended as an alternative to existing rainfall–runoff ANN models. Copyright © 2007 John Wiley & Sons, Ltd.     

Late Cretaceous blueschist facies metamorphism in southern Thrace (Turkey) and its geodynamic implications

A blueschist facies tectonic sliver, 9 km long and 1 km wide, crops out within the Miocene clastic rocks bounded by the strands of the North Anatolian Fault zone in southern Thrace, NW Turkey. Two types of blueschist facies rock assemblages occur in the sliver: (i) A serpentinite body with numerous dykes of incipient blueschist facies metadiabase (ii) a well‐foliated and thoroughly recrystallized rock assemblage consisting of blueschist, marble and metachert. Both are partially enveloped by an Upper Eocene wildflysch, which includes olistoliths of serpentinite–metadiabase, Upper Cretaceous and Palaeogene pelagic limestone, Upper Eocene reefal limestone, radiolarian chert, quartzite and minor greenschist. Field relations in combination with the bore core data suggest that the tectonic sliver forms a positive flower structure within the Miocene clastic rocks in a transpressional strike–slip setting, and represents an uplifted part of the pre‐Eocene basement. The blueschists are represented by lawsonite–glaucophane‐bearing assemblages equilibrated at 270–310 °C and ～0.8 GPa. The metadiabase dykes in the serpentinite, on the other hand, are represented by pumpellyite–glaucophane–lawsonite‐assemblages that most probably equilibrated below 290 °C and at 0.75 GPa. One metadiabase olistolith in the Upper Eocene flysch sequence contains the mineral assemblage epidote + pumpellyite + glaucophane, recording P–T conditions of 290–350 °C and 0.65–0.78 GPa, indicative of slightly lower depths and different thermal setting. Timing of the blueschist facies metamorphism is constrained to c. 86 Ma (Coniacian/Santonian) by Rb–Sr phengite–whole rock and incremental ⁴⁰Ar–³⁹Ar phengite dating on blueschists. The activity of the strike–slip fault post‐dates the blueschist facies metamorphism and exhumation, and is only responsible for the present outcrop pattern and post‐Miocene exhumation (～2 km). The high‐P/T metamorphic rocks of southern Thrace and the Biga Peninsula are located to the southeast of the Circum Rhodope Belt and indicate Late Cretaceous subduction and accretion under the northern continent, i.e. the Rhodope Massif, enveloped by the Circum Rhodope Belt. The Late Cretaceous is therefore a time of continued accretionary growth of this continental domain.     

Numbers,types, and compositions of an unbiased collection of cosmic spherules

Abstract— Micrometeorites collected from the bottom of the South Pole water well (SPWW) may represent a complete, well‐preserved sample of the cosmic dust that accreted on Earth from 1100–1500 A.D. We classified 1588 cosmic spherules in the size range 50–800 μm. The collection has 41% barred olivine spherules, 17% glass spheres, 12% cryptocrystalline spherules, 11% porphyritic olivine spherules, 12% relicgrain‐bearing spherules, 3% scoriaceous spherules, 2% I‐type spherules, 1% Ca‐AI‐Ti‐rich (CAT) spherules, and 1% G‐type spherules. We also found bubbly glass spherules, spherules with glass caps, and ones with sulfide coatings—particles that are absent from other collections. A classification sequence of the stony spherules (scoriaceous, relic‐grain‐bearing, porphyritic, barred olivine, cryptocrystalline, glass, and CAT) is consistent with progressive heating and evaporation of Fe from chondritic materials. The modern‐day accretion rate and size distribution measured at the SPWW can account for the stony spherules present in deep‐sea collection through preferential dissolution of glass and small stony spherules. However, weathering alone cannot account for the high accretion rate of I‐type spherules determined for two deep‐sea collections. The SPWW collection provides data to constrain models of atmospheric‐entry heating and to assess the effects of terrestrial weathering.