Kaolin-Kohlentonsteine im flözführenden Oberkarbon des Niederrheinisch-Westfälischen Steinkohlenreviers

Starting from general considerations of the rocks existing in the Ruhr Carboniferous and the mineral layers in coal seams, an informative review is given about the definition of clay stones and kaolin coal tonsteins as well as about the stratigraphic distribution of key horizons with special regard to the kaolin coal tonsteins. Information follows about the first evidence of individual kaolin coal tonsteins, their existence in the normal geologic columns and more recent stratigraphic sections as well as about the concentration of repositories. Besides, the kaolin coal tonsteins are characterized according to their macroscopic and microscopic external form. The paper reports about their material constituents (mineral components, trace elements, anorganic chemical constituents and organic substances in form of coal hydrates and amino acids). The paper closes with some statements about the importance and utilization of kaolin coal tonsteins to solve local and regional duties in mining geology.     

二氧化碳地质存储过程中沿井筒渗漏定性分析

二氧化碳沿井筒渗漏是二氧化碳地质埋存过程中所面临的重要风险之一.尤其是对于已经封堵的废弃井,由于获取井下的信息比较困难,因此评价废弃井的完整性是一个比较大的挑战.本文为评估二氧化碳沿废弃井渗漏提出了风险分析的方法.该方法包括了三个主要步骤:渗漏方案的制定,定量模拟及结果分析.所制定的渗漏方案将通过数值模拟进行定量分析及评价.本文将阐述该评价方法的第一步骤:渗漏方案的制定.该步骤为渗漏的定量模拟提供了理论基础.该方法被广泛接受并现场应用于德国某大型二氧化碳存储及提高天然气采收率项目中.     

Separation of iron from manganese and growth of manganese nodules as a consequence of diagenetic ageing of radiolarians

111 samples of diagenetically aged radiolarians sampled in the Central Pacific manganese nodules belt were investigated chemically and microscopically.

Authigenic clays of the smectite group are precipitated in the cavities of radiolarian tests; metal oxides are precipitated on the surfaces of radiolarian tests. During these processes a separation of iron from manganese takes place: about 96% of the iron is bound to smectites and all of the manganese is bound to the oxide coatings of the radiolarians.

With further diagenesis, radiolarian tests are dissolved together with their oxide coatings. This dissolution of the oxide coatings provides material for the growth of manganese nodules, material which is depleted in Fe and enriched in Mn, Cu, and Zn.

The smectite aggregates that fill the cavities of radiolarian tests contain iron bound to their crystal lattice. Whereas radiolarian tests are dissolved during the diagenesis, these smectite aggregates do not dissolve and thus become enriched in older samples.     

Some geochemical indicators for discrimination between diagenetic and hydrothermal metalliferous sediments

Two types of metalliferous sediments are known: hydrothermal (associated with tectonic faults) and diagenetic (enriched in precipitates from seawater). They are similar in their appearance and chemical composition.Only the first type is an indicator for hydrothermal discharge. Therefore, in exploration criteria for differentiating between the two are needed. Four possible indicators have been investigated and are discussed: (a) differences in P/Y correlation; (b) differences in Cr/Zr correlation; (c) different distribution patterns of REE; and (d) different As contents.The As content is easy to determine and seems to be (at the present time) the most suitable criterion for determining the genesis of the metalliferous sediments.     

Structure and resilience of overwintering habitats of Calanus finmarchicus in the Eastern Norwegian Sea

Very high concentrations of overwintering Calanus finmarchicus were found in the eastern Lofoten Basin of the Norwegian Sea close to the shelf break in January 2001–2002. A coupled 3D hydrodynamic and ecological model was used to study the formation of this deep overwintering aggregation and its stability. The ecological model includes nutrients, phytoplankton and microzooplankton in addition to a stage-structured model of C. finmarchicus. Using a Eulerian approach, the model was initiated with an overwintering stock evenly distributed in the oceanic regions of the Norwegian Sea, i.e. where depths>600 m. Spawning and development of the new generation take place in response to vertical mixing and phytoplankton development. Animals are assumed to begin their descent to overwintering depths of 700–1000 m as late stage Vs. Model results show that, in late summer, high concentrations of animals were found at overwintering depths near the shelf break north of the North Sea, off the northeastern Vøring Plateau and in the eastern Lofoten Basin along the slope of the Barents Sea shelf. They remained there for months due to deep eddies and southward, deep currents along the Norwegian shelf. The simulation experiments indicate that the combined effect of deep anticyclonic circulation and vertical migration behavior of the animals may explain the high concentrations of overwintering C. finmarchicus found in field surveys in the Eastern Lofoten Basin, close to the shelf break.     

An abyssal recipe

Fine- and microstructure observations indicate bottom-intensified turbulent dissipation above rough bathymetry associated with internal wave breaking. Simple analytic representations for the depth profile of turbulent dissipation are proposed here under the assumption that the near bottom wavefield is dominated by a baroclinic tide. This scheme is intended for use in numerical models and thus captures only the gross features of detailed solutions to the energy balance of the internal wavefield. The possible sensitivity of the magnitude and vertical variability of the dissipation rate profile to various environmental parameters is discussed. An expression for the diapycnal buoyancy flux is presented that explicitly treats the difference between the height of an isopycnal above the mean bottom and the actual bottom. This returns a diapycnal velocity estimate that is consistent with both tracer observations of downwelling and a basin scale mass budget that requires upwelling.     

Aftershock Distribution as a Constraint on the Geodetic Model of Coseismic Slip for the 2004 Parkfield Earthquake

Several studies of the 2004 Parkfield earthquake have linked the spatial distribution of the event’s aftershocks to the mainshock slip distribution on the fault. Using geodetic data, we find a model of coseismic slip for the 2004 Parkfield earthquake with the constraint that the edges of coseismic slip patches align with aftershocks. The constraint is applied by encouraging the curvature of coseismic slip in each model cell to be equal to the negative of the curvature of seismicity density. The large patch of peak slip about 15 km northwest of the 2004 hypocenter found in the curvature-constrained model is in good agreement in location and amplitude with previous geodetic studies and the majority of strong motion studies. The curvature-constrained solution shows slip primarily between aftershock “streaks” with the continuation of moderate levels of slip to the southeast. These observations are in good agreement with strong motion studies, but inconsistent with the majority of published geodetic slip models. Southeast of the 2004 hypocenter, a patch of peak slip observed in strong motion studies is absent from our curvature-constrained model, but the available GPS data do not resolve slip in this region. We conclude that the geodetic slip model constrained by the aftershock distribution fits the geodetic data quite well and that inconsistencies between models derived from seismic and geodetic data can be attributed largely to resolution issues.