Notes on the origin of inertinite macerals in coals: Observations on the importance of fungi in the origin of macrinite     

James C. Hower  Jennifer M.K. O'Keefe  Michael A. Watt  Timothy J. Pratt  Cortland F. Eble  J.D. Stucker  Allison R. Richardson  Irena J. Kostova 《International Journal of Coal Geology》2009,80(2):135-143

Macrinite is a, generally, rare inertinite maceral, often incorporating remnants and fragments of other macerals, including vitrinite, liptinite, and other inertinite. The associated inertinites include multiple forms of funginite. Funginite is also commonly found in association with vitrinite of slightly elevated reflectance and with degraded varieties of vitrinite. Together with the highly degraded macrinite, the latter two associations are here inferred to be part of a continuum of fungal and microbial degradation of peat. In any case, the origin of some macrinite is potentially distinct from that of inertinite generated by fire.  相似文献   

Postglacial to Holocene landscape evolution and process rates in steep alpine catchments     

Florian Kober  Kristina Hippe  Bernhard Salcher  Reto Grischott  Raphael Zurfluh  Irka Hajdas  Lukas Wacker  Marcus Christl  Susan Ivy-Ochs 《地球表面变化过程与地形》2019,44(1):242-258

Climate change and high magnitude mass wasting events pose adverse societal effects and hazards, especially in alpine regions. Quantification of such geomorphic processes and their rates is therefore critical but is often hampered by the lack of appropriate techniques and the various spatiotemporal scales involved in these studies. Here we exploit both in situ cosmogenic beryllium-10 (¹⁰Be) and carbon-14 (¹⁴C) nuclide concentrations for deducing exposure ages and tracing of sediment through small alpine debris flow catchments in central Switzerland. The sediment cascade and modern processes we track from the source areas, through debris flow torrents to their final export out into sink regions with cosmogenic nuclides over an unprecedented five-year time series with seasonal resolution. Data from a seismic survey and a 90 m core revealed a glacially overdeepened basin, filled with glacial and paraglacial sediments. Surface exposure dating of fan boulders and radiocarbon ages constrain the valley fill from the last deglaciation until the Holocene and show that most of the fan existed in early Holocene times already. Current fan processes are controlled by episodic debris flow activity, snow (firn) and rock avalanches. Field investigations, digital elevation models (DEMs) of difference and geomorphic analysis agree with sediment fingerprinting with cosmogenic nuclides, highlighting that the bulk of material exported today at the outlet of the subcatchments derives from the lower fans. Cosmogenic nuclide concentrations steadily decrease from headwater sources to distal fan channels due to the incorporation of material with lower nuclide concentrations. Further downstream the admixture of sediment from catchments with less frequent debris flow activity can dilute the cosmogenic nuclide signals from debris flow dominated catchments but may also reach thresholds where buffering is limited. Consequently, careful assessment of boundary conditions and driving forces is required when apparent denudation rates derived from cosmogenic nuclide analysis are upscaled to larger regions. © 2018 John Wiley & Sons, Ltd.  相似文献   

The Effect of Atmospheric Organic Compounds on the Fe-Catalyzed S(IV) Autoxidation in Aqueous Solution     

Irena Grgić  Andreja Dovžan  Gorazd Berčič  Vida Hudnik 《Journal of Atmospheric Chemistry》1998,29(3):315-337

Laboratory experiments were conducted with real atmospheric aerosol particles as well as with synthetic solutions under dark conditions, to simulate some of the chemical features of aerosols. In solutions obtained by the leaching of aerosols (size range >D _ae: 0.4–1.6 m) that contained sufficient amounts of transition metal ions (e.g. Fe) and organic species (e.g. oxalate), S(IV) oxidation rates were significantly lower than those expected from the Fe-catalyzed S(IV) autoxidation in Milli-Q water. The results suggest that oxalate is responsible for much of the observed inhibition. Acetate and formate also inhibit the reaction, but to a much lesser extent. Oxalate has a strong inhibiting effect on the Fe-catalyzed S(IV) autoxidation at all investigated pH values (2.8, 3.7 and 4.5). It was established that Fe(III)-oxalato complexes affect the redox cycling of Fe(II)/Fe(III) and that the observed decrease of the reaction rate is caused by the reduced amount of catalytically active Fe(III) due to the complexation with oxalate. For the system Fe-S(IV)-O₂-oxalate at initial pH 3.7 the reaction rate was calculated using exponential simplification to account for oxalate influence on the amount of free Fe(III) by the following equation:–r_S(IV) = k · [S(IV)] · [Fe(III))] · e ^-b·[Ox]  相似文献   

Landslide deposits as stratigraphical markers for a sequence‐based glacial stratigraphy: a case study of a Younger Dryas system in the Eastern Alps          下载免费PDF全文

Mathias G. Bichler  Martin Reindl  Jürgen M. Reitner  Ruth Drescher‐Schneider  Christian Wirsig  Marcus Christl  Irka Hajdas  Susan Ivy‐Ochs 《Boreas: An International Journal of Quaternary Research》2016,45(3):537-551

Detailed ¹⁰Be and ¹⁴C dating and supporting pollen analysis of Alpine Lateglacial glacial and landslide deposits in the Hohen Tauern Mountains (Austria) constrain a sequence‐based stratigraphy comprising a major landslide (13.0±1.1 ka) overlain by till and termino‐lateral moraines of an advancing (12.6±1.0 ka) and retreating (11.3±0.8 ka) glacier in turn overlain by a minor landslide (10.8±1.1 ka). These results define glacier activity during the Younger Dryas age Egesen stadial bracketed by landslide activities during the Bølling‐Allerød interstadial and the Preboreal. In contrast to recent studies on Holocene glaciation in the Alps, no traces of any Holocene glacier advance bigger than during the Little Ice Age are documented. Furthermore, this study demonstrates the advantages of using an allostratigraphical approach based on unconformity‐bounded sedimentary units as a tool for glacial stratigraphy in formerly glaciated mountain regions, rather than a stratigraphy based on either isolated morphological features or lithostratigraphical characteristics.  相似文献   

An Impacting Descent Probe for Europa and the Other Galilean Moons of Jupiter     

P. Wurz  D. Lasi  N. Thomas  D. Piazza  A. Galli  M. Jutzi  S. Barabash  M. Wieser  W. Magnes  H. Lammer  U. Auster  L. I. Gurvits  W. Hajdas 《Earth, Moon, and Planets》2017,120(2):113-146

We present a study of an impacting descent probe that increases the science return of spacecraft orbiting or passing an atmosphere-less planetary bodies of the solar system, such as the Galilean moons of Jupiter. The descent probe is a carry-on small spacecraft (<100 kg), to be deployed by the mother spacecraft, that brings itself onto a collisional trajectory with the targeted planetary body in a simple manner. A possible science payload includes instruments for surface imaging, characterisation of the neutral exosphere, and magnetic field and plasma measurement near the target body down to very low-altitudes (~1 km), during the probe’s fast (~km/s) descent to the surface until impact. The science goals and the concept of operation are discussed with particular reference to Europa, including options for flying through water plumes and after-impact retrieval of very-low altitude science data. All in all, it is demonstrated how the descent probe has the potential to provide a high science return to a mission at a low extra level of complexity, engineering effort, and risk. This study builds upon earlier studies for a Callisto Descent Probe for the former Europa-Jupiter System Mission of ESA and NASA, and extends them with a detailed assessment of a descent probe designed to be an additional science payload for the NASA Europa Mission.  相似文献   

Weathering of fuel oil spill on the east Mediterranean coast, Ashdod, Israel   总被引：1，自引：0，他引：1  

Shai Ezra  Shimon Feinstein  Ithamar Pelly  Dan Bauman  Irena Miloslavsky 《Organic Geochemistry》2000,31(12)

Residual fuel oil spilled into the sea from the Eshkol power station on 8 February, 1998 contaminated about 9 km of the foreshore north of the Ashdod harbour. A study of the aliphatic, polycyclic alkane and polyaromatic hydrocarbon (PAH) composition of the spilled oil shows rapid weathering in the early stages followed by gradual slowdown after about three months. Weathering of isoprenoids and PAH compounds and variation in Pr/Ph ratio appear to occur almost contemporaneously with that of n-alkanes, at a relatively moderate level of degradation, when much of the >C₂₀ n-alkane envelope is still well preserved. Depletion of various compounds in accordance with molecular size rather than molecular structure appears to imply that physical weathering processes, i.e. evaporation and perhaps flushing due to wave energy, might have played an important role in the degradation of the spilled residual fuel oil in this study case.  相似文献   

Book Review     

Irena Lucifredi 《Pure and Applied Geophysics》2011,168(5):947-948

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Macroalgal diversity along the Baltic Sea salinity gradient challenges Remane's species-minimum concept     

Schubert H  Feuerpfeil P  Marquardt R  Telesh I  Skarlato S 《Marine pollution bulletin》2011,62(9):1948-1956

Remane’s species-minimum concept, which states that the lowest number of taxa occurs at the horohalinicum (5-8 psu), was tested by investigating macroalgal diversity on hard substrates along the natural salinity gradient in the Baltic Sea. Field data on species occurrence and abundance were collected by SCUBA diving along 10 transects of the Finnish, Swedish and German coasts, covering a salinity range from 3.9 to 27 psu. Macroalgal species numbers declined steadily with salinity, decreasing until 7.2 psu was reached, but in the horohalinicum, a marked reduction of species number and a change in diversity were indicated by the Shannon index and evenness values. The non-linear decrease in macroalgal diversity at 5-8 psu and the lack of increase in species numbers at salinities below 5 psu imply a restricted applicability of Remane’s species-minimum concept to macroalgae.  相似文献   

Planktonic rotifers in mining lakes in the Silesian Upland: Relationship to environmental parameters   总被引：1，自引：0，他引：1  

Irena Bielańska-Grajner  Anna G?adysz 《Limnologica》2010,40(1):67-72

The effects of coal-mine waters on the structure and the density of planktonic rotifer communities were studied in lakes formed as a result of subsidence due to mining (collapse of underground tunnels). Water samples were collected according to the standard methods from four mining lakes in Tychy-Czu?ów (near Katowice, southern Poland), twice a month from June till October in 2004-2006. Two of the studied lakes were fed by mine waters but differed in flow rate, conductivity, water pH, and the amount of aquatic vegetation. The effects of those factors on the planktonic rotifer communities were analysed. In total, 83 species and forms of rotifers were recorded. The highest diversity of rotifers was found in the lakes with the largest patches of aquatic vegetation, while the highest density of rotifers was observed in the smallest and the most eutrophicated lake. High-water conductivity limited both species diversity and densities of rotifers. The rotifer communities of the studied lakes differed significantly in species diversity, although all the lakes were dominated by eurytopic species: Keratella cochlearis, Brachionus angularis, Brachionus calyciflorus, and Polyarthra sp. In the largest lake, characterized by the lowest conductivity and pH, the superdominant was Polyarthra luminosa, which in the other lakes was rare or absent. Higher conductivity was correlated with a lower density of P. luminosa, Brachionus diversicornis, K. cochlearis f. tecta, and a higher density of B. calyciflorus. In the lakes with the largest patches of aquatic vegetation, conductivity affected the number of dominant rotifer species. Apparently no other abiotic factors (pH, phosphates, and nitrates) affected the rotifer communities.  相似文献   

Experimental Infiltration Tests on Existing Permeable Pavement Surfaces          下载免费PDF全文

Sara Simona Cipolla  Marco Maglionico  Irena Stojkov 《洁净——土壤、空气、水》2016,44(1):89-95

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